A visit to Trang An, Vietnam

 

Tràng An is a scenic area near Ninh Bình, Vietnam renowned for its boat cave tours. Tthe Trang An Scenic Landscape Complex was inscribed as a UNESCO World Heritage Site 23 June 2014, at the 38th session of the World Heritage Committee in Doha

 

A visit to Vietnam is incomplete without visiting Trang An.

The tourist boats are safe factory made ones with no seams

 

There are lots of tourists visiting Trang An

 

The female rowers can take a boat load of 4 passengers on about half an hour’s rowing sightseeing. I rowed for a while and got tired.

 

Passenger safety is taken seriously, and all have to wear life jackets although the female rowers do not.

 

 

 

 

 

we passed by a temple

the boats enter a tunnel

 

 

We entered the subterranean tunnel

 

 

 

it was dark inside as the tunnel was long

 

there were lights at points inside

 

 

 

at places the roof was low

 

 

and the side wall close at times

 

 

 

light at the end of the tunnel

 

outside at last

 

 

 

 

 

 

ore beautiful scene

 

 

we entered another tunnel

 

this tunnel is shorter

 

 

 

 

 

there were no lights inside and we were out in no time

 

 

again another tunnel, this one near human habitation or place of worship

 

a wide and short one

 

 

more beautiful scenes

 

 

 

 

boats of locals are different

 

 

 

 

 

 

another tunnel again!

 

and shorter too

 

 

 

we finally got ashore

 

 

Trang An, Vietnam, was a memorable trip

Loch Ness monster

Loch Ness monster statute at the boat ride stop

 

We went to Loch Ness during my recent visit to Edinburgh, not to see the Loch Ness monster but to see the famous Loch Ness which is the second largest Scottish Loch.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Loch Ness is the second largest Scottish loch by surface area at 22 sq mi (56 km2) after Loch Lomond, but due to its great depth, it is the largest by volume in the British Isles. Its deepest point is 755 ft (230 m), making it the second deepest loch in Scotland after Loch Morar. A 2016 survey claimed to have discovered a crevice that pushed the depth to 889 ft (271 m) but further research determined it to be a sonar anomaly. It contains more fresh water than all the lakes in England and Wales combined, and is the largest body of water on the Great Glen Fault, which runs from Inverness in the north to Fort William in the south.

 

 

 

 

 

 

 

 

 

Geology

Loch Ness lies along the Great Glen Fault, which forms a line of weakness in the rocks which has been excavated by glacial erosion, forming the Great Glen and the basins of Loch Lochy, Loch Oich and Loch Ness.

It is because it is on the Great Glen Fault that the Loch Ness is so straight (as with the 3rd Ayeyarwaddy defile at Thabeik Kyinn).

 

Loch Ness is narrow and long.

Loch Ness (/ˌlɒx ˈnɛs/; Scottish Gaelic: Loch Nis, [l̪ˠɔxˈniʃ]) is a large, deep, freshwater loch in the Scottish Highlands extending for approximately 23 miles (37 km) southwest of Inverness. Its surface is 52 ft (16 m) above sea level. Loch Ness is best known for alleged sightings of the cryptozoological Loch Ness Monster, also known affectionately as “Nessie”. It is connected at the southern end by the River Oich and a section of the Caledonian Canal to Loch Oich. At the northern end there is the Bona Narrows which opens out into Loch Dochfour, which feeds the River Ness and a further section of canal to Inverness. It is one of a series of interconnected, murky bodies of water in Scotland; its water visibility is exceptionally low due to a high peat content in the surrounding soil.

 

Loch Ness Monster

 

 

Loch Ness is thought by some to be the home of the Loch Ness Monster (also known as “Nessie“), a cryptid, reputedly a large unknown animal. It is similar to other supposed lake monsters in Scotland and elsewhere, though its description varies from one account to the next. Popular interest and belief in the animal’s existence has varied since it was first brought to the world’s attention in 1933.

Spicers (1933)

Modern interest in the monster was sparked by a sighting on 22 July 1933, when George Spicer and his wife saw “a most extraordinary form of animal” cross the road in front of their car. They described the creature as having a large body (about 4 feet (1.2 m) high and 25 feet (8 m) long) and a long, wavy, narrow neck, slightly thicker than an elephant’s trunk and as long as the 10–12-foot (3–4 m) width of the road. They saw no limbs. It lurched across the road towards the loch 20 yards (20 m) away, leaving a trail of broken undergrowth in its wake.

In August 1933 a motorcyclist, Arthur Grant, claimed to have nearly hit the creature while approaching Abriachan (near the north-eastern end of the loch) at about 1 a.m. on a moonlit night. According to Grant, it had a small head attached to a long neck; the creature saw him, and crossed the road back to the loch. Grant, a veterinary student, described it as a cross between a seal and a plesiosaur. He said he dismounted and followed it to the loch, but only saw ripples. Some interpret the story as a humorous explanation of a motorcycle accident.

Sightings of the monster increased after a road was built along the loch in early 1933, bringing workers and tourists to the formerly-isolated area. Sporadic land sightings continued until 1963, when poor-quality film of the creature was shot in the loch from a distance of 4 kilometres (2.5 mi).

This photo was later proved to be a hoax but interest and popularity soared.

 

In folklore, the Loch Ness Monster is an aquatic being which reputedly inhabits Loch Ness in the Scottish Highlands. It is similar to other supposed lake monsters in Scotland and elsewhere, although its description varies; it is described by most as large. Popular interest and belief in the creature has varied since it was brought to worldwide attention in 1933. Evidence of its existence is anecdotal, with few, disputed photographs and sonar readings.

The most common speculation among believers is that the creature represents a line of long-surviving plesiosaurs.^[5] While adherents of cryptozoology, a pseudoscience, describe the creature as a cryptid,^[6] the scientific community regards the Loch Ness Monster as a myth, explaining sightings as misidentifications of mundane objects, hoaxes, and wishful thinking.^[7] The creature has been affectionately called Nessie^[b] (Scottish Gaelic: Niseag)^[8] since the 1940s.

 

Origins

The word “monster” was reportedly applied for the first time to the creature on 2 May 1933 by Alex Campbell, water bailiff for Loch Ness and a part-time journalist, in an Inverness Courier report.^[10][11][12] On 4 August 1933 the Courier published a report by Londoner George Spicer that several weeks earlier, while they were driving around the loch, he and his wife saw “the nearest approach to a dragon or pre-historic animal that I have ever seen in my life” trundling across the road toward the loch with “an animal” in its mouth.^[13] Letters began appearing in the Courier, often anonymously, claiming land or water sightings by the writer, their family or acquaintances or remembered stories.^[14] The accounts reached the media, which described a “monster fish”, “sea serpent”, or “dragon”^[15] and eventually settled on “Loch Ness monster”.^[16]

On 6 December 1933 the first purported photograph of the monster, taken by Hugh Gray, was published in the Daily Express;^[17] the Secretary of State for Scotland soon ordered police to prevent any attacks on it.^[18] In 1934, interest was further piqued by the “surgeon’s photograph”. That year, R. T. Gould published an account^[19] of the author’s investigation and a record of reports predating 1933. Other authors have claimed sightings of the monster dating to the sixth century AD.

 

History

Saint Columba (565)

The earliest report of a monster in the vicinity of Loch Ness appears in the Life of St. Columba by Adomnán, written in the seventh century AD.^[20] According to Adomnán, writing about a century after the events described, Irish monk Saint Columba was staying in the land of the Picts with his companions when he encountered local residents burying a man by the River Ness. They explained that the man was swimming in the river when he was attacked by a “water beast” which mauled him and dragged him underwater. Although they tried to rescue him in a boat, he was dead. Columba sent a follower, Luigne moccu Min, to swim across the river. The beast approached him, but Columba made the sign of the cross and said: “Go no further. Do not touch the man. Go back at once.”^[21] The creature stopped as if it had been “pulled back with ropes” and fled, and Columba’s men and the Picts gave thanks for what they perceived as a miracle.^[21] The oldest manuscript relating to this story was put online in 2012.^[22]

Believers in the monster point to this story, set in the River Ness rather than the loch itself, as evidence for the creature’s existence as early as the sixth century.^[23] Sceptics question the narrative’s reliability, noting that water-beast stories were extremely common in medieval hagiographies and Adomnán’s tale probably recycles a common motif attached to a local landmark.^[24] According to sceptics, Adomnán’s story may be independent of the modern Loch Ness Monster legend and became attached to it by believers seeking to bolster their claims.^[23] According to R. Binns, this account is the most credible of the early sightings of the monster; all other claims before 1933 are dubious and do not prove a tradition of sightings before that date.^[11]

D. Mackenzie (1871–72)

Pre-1933 sightings of the creature were rare.^[25] In October 1871 (or 1872), D. Mackenzie of Balnain reportedly saw an object resembling a log or an upturned boat “wriggling and churning up the water”. The object moved slowly at first, disappearing at a faster speed.^[26][27] Mackenzie sent his story in a letter to Rupert Gould in 1934, shortly after popular interest in the monster increased.^[27]

William Fraser (1938)

In 1938 William Fraser, chief constable of Inverness-shire, wrote a letter that the monster existed beyond doubt and expressed concern about a hunting party which had arrived (with a custom-made harpoon gun) determined to catch the monster “dead or alive”. He believed his power to protect the monster from the hunters was “very doubtful”. The letter was released by the National Archives of Scotland on 27 April 2010.^[33][34]

C. B. Farrel (1943)

In May 1943, C. B. Farrel of the Royal Observer Corps was reportedly distracted from his duties by a Nessie sighting. He claimed to have been about 230 metres (750 ft) away from a large-eyed, “finned” creature with a 6-to-9-metre (20 to 30 ft) long body and a neck which protruded about 1.2 to 1.5 m (4 to 5 ft) out of the water.^[35]

Sonar readings (1954)

In December 1954, sonar readings were taken by the fishing boat Rival III. Its crew noted a large object keeping pace with the vessel at a depth of 146 metres (479 ft). It was detected for 800 m (2,600 ft) before contact was lost and regained.^[35] Previous sonar attempts were inconclusive or negative.

 

Photos and video

Hugh Gray photograph (1933)

On 12 November 1933, Hugh Gray was walking along the loch after church when he reportedly saw a large creature rising from the lake. Gray took several pictures, but only one was successfully developed. The blurry image appeared to show a creature with a long tail and thick body on the surface of the loch.^[36] Although critics have claimed that the photograph is of Gray’s Labrador Retriever swimming towards the camera (possibly carrying a stick), researcher Roland Watson suggests that there is an eel-like head on the right side of the image.^[37] This is the first known photograph of the creature.

“Surgeon’s photograph” (1934)

The “surgeon’s photograph” is reportedly the first photo of the creature’s head and neck.^[38] Supposedly taken by Robert Kenneth Wilson, a London gynaecologist, it was published in the Daily Mail on 21 April 1934.^[39] Wilson’s refusal to have his name associated with its led to its being known as the “surgeon’s photograph”.^[40] According to Wilson, he was looking at the loch when he saw the monster, grabbed his camera and snapped four photos. Only two exposures came out clearly; the first reportedly shows a small head and back, and the second shows a similar head in a diving position. The first photo became well-known, and the second attracted little publicity because of its blurriness.

Although for a number of years the photo was considered evidence of the monster, sceptics dismissed it as driftwood,^[27] an elephant,^[41] an otter, or a bird. The photo’s scale was controversial; it is often shown cropped (making the creature seem large and the ripples like waves), while the uncropped shot shows the other end of the loch and the monster in the centre. The ripples in the photo were found to fit the size and pattern of small ripples, unlike large waves photographed up close. Analysis of the original image fostered further doubt. In 1993, the makers of the Discovery Communications documentary Loch Ness Discovered analysed the uncropped image and found a white object visible in every version of the photo (implying that it was on the negative). It was believed to be the cause of the ripples, as if the object was being towed, although the possibility of a blemish on the negative could not be ruled out. An analysis of the full photograph indicated that the object was small, about 60 to 90 cm (2 to 3 ft) long.^[40]

Since 1994, most agree that the photo was an elaborate hoax.^[40] It had been accused of being a fake in a 7 December 1975 Sunday Telegraph article which fell into obscurity.^[42] Details of how the photo was taken were published in the 1999 book, Nessie – the Surgeon’s Photograph Exposed, which contains a facsimile of the 1975 Sunday Telegraph article.^[43] The creature was reportedly a toy submarine built by Christian Spurling, the son-in-law of Marmaduke Wetherell. Wetherell had been publicly ridiculed by his employer, the Daily Mail, after he found “Nessie footprints” which turned out to be a hoax. To get revenge on the Mail, Wetherell perpetrated his hoax with co-conspirators Spurling (sculpture specialist), Ian Wetherell (his son, who bought the material for the fake), and Maurice Chambers (an insurance agent).^[44] The toy submarine was bought from F. W. Woolworths, and its head and neck were made from wood putty. After testing it in a local pond the group went to Loch Ness, where Ian Wetherell took the photos near the Altsaigh Tea House. When they heard a water bailiff approaching, Duke Wetherell sank the model with his foot and it is “presumably still somewhere in Loch Ness”.^[27] Chambers gave the photographic plates to Wilson, a friend of his who enjoyed “a good practical joke”. Wilson brought the plates to Ogston’s, an Inverness chemist, and gave them to George Morrison for development. He sold the first photo to the Daily Mail,^[45] who then announced that the monster had been photographed.^[27]

Little is known of the second photo; it is often ignored by researchers, who believe its quality too poor and its differences from the first photo too great to warrant analysis. It shows a head similar to the first photo, with a more turbulent wave pattern and possibly taken at a different time and location in the loch. Some believe it to be an earlier, cruder attempt at a hoax,^[46] and others (including Roy Mackal and Maurice Burton) consider it a picture of a diving bird or otter which Wilson mistook for the monster.^[26] According to Morrison, when the plates were developed Wilson was uninterested in the second photo; he allowed Morrison to keep the negative, and the second photo was rediscovered years later.^[47] When asked about the second photo by the Ness Information Service Newsletter, Spurling ” … was vague, thought it might have been a piece of wood they were trying out as a monster, but [was] not sure.”^[48]

The hoax story is disputed by Henry Bauer, who claims that the debunking is evidence of bias and asks why the perpetrators did not reveal their plot earlier to embarrass the newspaper.^[49] According to Alastair Boyd, a researcher who uncovered the hoax, the Loch Ness Monster is real; the surgeon’s photo hoax does not mean that other photos, eyewitness reports, and footage of the creature are also, and he claims to have seen it.^[50]

Tim Dinsdale disputes the claim that the photograph is a hoax in his book, Loch Ness Monster, after reportedly extensively studying the photograph from a number of angles: “Upon really close examination, there are certain rather obscure features in the picture which have a profound significance.”^[51] Two are a solid object breaking the surface to the right of the neck and a mark to the left and behind the neck.^[52] According to Dinsdale, the objects are either a subtle fake or part of the monster.^[53] Others are vague, small ripples behind the neck, apparently after the neck broke the surface.^[53]

Taylor film (1938)

In 1938, South African tourist G. E. Taylor filmed something in the loch for three minutes on 16 mm colour film. The film was obtained by popular-science writer Maurice Burton, who did not show it to author Peter Costello and the Loch Ness Investigation Bureau.^{[citation needed]} A single frame was published in his 1961 book, The Elusive Monster.

Dinsdale film (1960)

Aeronautical engineer Tim Dinsdale filmed a hump which left a wake crossing Loch Ness in 1960.^[54] Dinsdale, who reportedly had the sighting on his final day of search, described it as reddish with a blotch on its side. He said that when he mounted his camera the object began to move, and he shot 40 feet of film. According to JARIC, the object was “probably animate”.^{[55][third-party source needed]} Others were sceptical, saying that the “hump” cannot be ruled out as being a boat^[56] and when the contrast is increased, a man in a boat can be seen.^[55]

In 1993 Discovery Communications produced a documentary, Loch Ness Discovered, with a digital enhancement of the Dinsdale film. A person who enhanced the film noticed a shadow in the negative which was not obvious in the developed film. By enhancing and overlaying frames, he found what appeared to be the rear body of a creature underwater: “Before I saw the film, I thought the Loch Ness Monster was a load of rubbish. Having done the enhancement, I’m not so sure”.^[50] According to sceptics, the angle of the film from the horizontal and the sun’s angle that day made underwater shadows unlikely.^[57] Although the darker water is coincidentally shaped like a body,^[58] there may be a smaller object (a second hump or a head) in front of the hump.^[58]

“Loch Ness Muppet” (1977)

On 21 May 1977 Anthony “Doc” Shiels, camping next to Urquhart Castle, took “some of the clearest pictures of the monster until this day”.^{[citation needed]} Shiels, a magician and psychic, claimed to have summoned the animal out of the water. He later described it as an “elephant squid”, claiming the long neck shown in the photograph is actually the squid’s “trunk” and that white spot at the base of the neck is its eye. Due to the lack of ripples, it has been declared a hoax by a number of people and received its name because of its staged look.^[59][60][61]

Holmes video (2007)

On 26 May 2007, 55-year-old laboratory technician Gordon Holmes videotaped what he said was “this jet black thing, about 14 metres (46 ft) long, moving fairly fast in the water.”^[62] Adrian Shine, a marine biologist at the Loch Ness 2000 Centre in Drumnadrochit, described the footage as among “the best footage [he had] ever seen.”^[62] BBC Scotland broadcast the video on 29 May 2007.^[63] STV News North Tonight aired the footage on 28 May 2007 and interviewed Holmes. Shine was also interviewed, and suggested that the footage was an otter, seal or water bird.^[64] According to Joe Nickell, the footage shows a beaver or otter swimming in the loch.^[65]

Sonar image (2011)

On 24 August 2011 Loch Ness boat captain Marcus Atkinson photographed a sonar image of a 1.5-metre (4 ft 11 in), unidentified object which seemed to follow his boat for two minutes at a depth of 23 m (75 ft), and ruled out the possibility of a small fish or seal. In April 2012, a scientist from the National Oceanography Centre said that the image is a bloom of algae and zooplankton.^[66]

George Edwards photograph (2011)

On 3 August 2012, skipper George Edwards published what he claimed to be “the most convincing Nessie photograph ever”,^{[citation needed]} which he said he took on 2 November 2011. Edwards’ photograph shows a hump above the water which, he said, remained there for five to ten minutes. According to Edwards, the photograph was independently verified by a Nessie sighting specialist and a group of US military monster experts. Edwards reportedly spent 60 hours per week on the loch aboard his boat, Nessie Hunter IV, on which he takes tourists for rides on the lake and claimed to have searched for the monster for 26 years.^[67][68] Edwards said, “In my opinion, it probably looks kind of like a manatee, but not a mammal. When people see three humps, they’re probably just seeing three separate monsters.”^[69]

Other researchers have questioned the photograph’s authenticity, and Loch Ness researcher Steve Feltham suggested that the object in the water is a fibreglass hump used in a National Geographic Channel documentary in which Edwards had participated.^[70] Researcher Dick Raynor has questioned Edwards’ claim of discovering a deeper bottom of Loch Ness, which Raynor calls “Edwards Deep”. He found inconsistencies between Edwards’ claims for the location and conditions of the photograph and the actual location and weather conditions that day. According to Raynor, Edwards told him he had faked a photograph in 1986 which he claimed was genuine in the Nat Geo documentary.^[71] Although Edwards admitted in October 2013 that his 2011 photograph was a hoax,^[72] he insisted that the 1986 photograph was genuine.^[73]

David Elder video (2013)

On 27 August 2013, tourist David Elder presented a five-minute video of a “mysterious wave” in the loch. According to Elder, the wave was produced by a 4.5 m (15 ft) “solid black object” just under the surface of the water.^[74] Elder, 50, from East Kilbride, South Lanarkshire, was taking a picture of a swan at the Fort Augustus pier on the south-western end of the loch,^[75] when he captured the movement.^[76] He said, “The water was very still at the time and there were no ripples coming off the wave and no other activity on the water.”^[76] Sceptics suggested that the wave may have been caused by a wind gust.^[77]

Apple Maps photograph (2014)

On 19 April 2014, it was reported^[4] that a satellite image on Apple Maps showed what appeared to be a large creature (thought by some to be the Loch Ness Monster) just below the surface of Loch Ness. At the loch’s far north, the image appeared about 30 metres (98 ft) long. Possible explanations were the wake of a boat (with the boat itself lost in image stitching or low contrast), seal-caused ripples, or floating wood.^[78][79]

Google Street View (2015)

Google commemorated the 81st anniversary of the “surgeon’s photograph” with a Google Doodle,^[80] and added a new feature to Google Street View with which users can explore the loch above and below the water.^[81][82] Google reportedly spent a week at Loch Ness collecting imagery with a street-view “trekker” camera, attaching it to a boat to photograph above the surface and collaborating with members of the Catlin Seaview Survey to photograph underwater.^[83]

 

Searches

Edward Mountain expedition (1934)

After reading Rupert Gould‘s The Loch Ness Monster and Others,^[19] Edward Mountain financed a search. Twenty men with binoculars and cameras positioned themselves around the loch from 9 am to 6 pm for five weeks, beginning on 13 July 1934. Although 21 photographs were taken, none was considered conclusive. Supervisor James Fraser remained by the loch filming on 15 September 1934; the film is now lost.^[84] Zoologists and professors of natural history concluded that the film showed a seal, possibly a grey seal.^[85]

Loch Ness Phenomena Investigation Bureau (1962–1972)

The Loch Ness Phenomena Investigation Bureau (LNPIB) was a UK-based society formed in 1962 by Norman Collins, R. S. R. Fitter, politician David James, Peter Scott and Constance Whyte^[86] “to study Loch Ness to identify the creature known as the Loch Ness Monster or determine the causes of reports of it.”^[87] The society’s name was later shortened to the Loch Ness Investigation Bureau (LNIB), and it disbanded in 1972. The LNIB had an annual subscription charge, which covered administration. Its main activity was encouraging groups of self-funded volunteers to watch the loch from vantage points with film cameras with telescopic lenses. From 1965 to 1972 it had a caravan camp and viewing platform at Achnahannet, and sent observers to other locations up and down the loch.^[88] According to the bureau’s 1969 annual report ^[89] it had 1,030 members, of whom 588 were from the UK.

Sonar study (1967–1968)

D. Gordon Tucker, chair of the Department of Electronic and Electrical Engineering at the University of Birmingham, volunteered his services as a sonar developer and expert at Loch Ness in 1968.^[90] His gesture, part of a larger effort led by the LNPIB from 1967 to 1968, involved collaboration between volunteers and professionals in a number of fields. Tucker had chosen Loch Ness as the test site for a prototype sonar transducer with a maximum range of 800 m (2,600 ft). The device was fixed underwater at Temple Pier in Urquhart Bay and directed at the opposite shore, drawing an acoustic “net” across the loch through which no moving object could pass undetected. During the two-week trial in August, multiple targets 6 m (20 ft) in length were identified rising from and diving to the loch bottom. Analysis of diving profiles ruled out air-breathers, because the targets never surfaced or moved shallower than midwater.^{[citation needed]}

Robert Rines studies (1972, 1975, 2001, 2008)

In 1972, a group of researchers from the Academy of Applied Science led by Robert H. Rines conducted a search for the monster involving sonar examination of the loch depths for unusual activity. Rines took precautions to avoid murky water with floating wood and peat.^{[citation needed]} A submersible camera with a floodlight was deployed to record images below the surface. If Rines detected anything on the sonar, he turned the light on and took pictures.

On 8 August Rines’ Raytheon DE-725C sonar unit, operating at a frequency of 200 kHz and anchored at a depth of 11 metres (36 ft), identified a moving target (or targets) estimated by echo strength at 6 to 9 metres (20 to 30 ft) in length. Specialists from Raytheon, Simrad (now Kongsberg Maritime), Hydroacoustics, Marty Klein of MIT and Klein Associates (a side-scan sonar producer) and Ira Dyer of MIT’s Department of Ocean Engineering were on hand to examine the data. P. Skitzki of Raytheon suggested that the data indicated a 3-metre (10 ft) protuberance projecting from one of the echoes. According to author Roy Mackal, the shape was a “highly flexible laterally flattened tail” or the misinterpreted return from two animals swimming together.^[91]

Concurrent with the sonar readings, the floodlit camera obtained a pair of underwater photographs. Both depicted what appeared to be a rhomboid flipper, although sceptics have dismissed the images as the bottom of the loch, air bubbles, a rock, or a fish fin. The apparent flipper was photographed in different positions, indicating movement.^[92] The first flipper photo is better-known than the second, and both were enhanced and retouched from the original negatives. According to team member Charles Wyckoff, the photos were retouched to superimpose the flipper; the original enhancement showed a considerably less-distinct object. No one is sure how the originals were altered.^[93]

British naturalist Peter Scott announced in 1975, on the basis of the photographs, that the creature’s scientific name would be Nessiteras rhombopteryx (Greek for “Ness monster with diamond-shaped fin”).^[94] Scott intended that the name would enable the creature to be added to the British register of protected wildlife. Scottish politician Nicholas Fairbairn called the name an anagram for “Monster hoax by Sir Peter S”.^[95][96]

Another sonar contact was made, this time with two objects estimated to be about 9 metres (30 ft). The strobe camera photographed two large, white, lumpy objects surrounded by a flurry of bubbles. Some interpreted the objects as two plesiosaur-like animals, suggesting several large animals living in Loch Ness. This photograph has rarely been published.

In 2001, Rines’ Academy of Applied Science videotaped a V-shaped wake traversing still water on a calm day. The academy also videotaped an object on the floor of the loch resembling a carcass and found marine clamshells and a fungus-like organism not normally found in freshwater lochs, a suggested connection to the sea and a possible entry for the creature.^[97]

In 2008 Rines theorised that the creature may have become extinct, citing the lack of significant sonar readings and a decline in eyewitness accounts. He undertook a final expedition, using sonar and an underwater camera in an attempt to find a carcass. Rines believed that the animals may have failed to adapt to temperature changes resulting from global warming.^[98]

Operation Deepscan (1987)

Operation Deepscan was conducted in 1987.^[99] Twenty-four boats equipped with echosounder equipment were deployed across the width of the loch, and simultaneously sent acoustic waves. According to BBC News the scientists had made sonar contact with an unidentified object of unusual size.^{[citation needed]} The researchers returned, re-scanning the area. Analysis of the echosounder images seemed to indicate debris at the bottom of the loch, although there was motion in three of the pictures. Adrian Shine speculated, based on size, that they might be seals which had entered the loch.^[100]

Sonar expert Darrell Lowrance, founder of Lowrance Electronics, donated a number of echosounder units used in the operation. After examining a sonar return indicating a large, moving object at a depth of 180 metres (590 ft) near Urquhart Bay, Lowrance said: “There’s something here that we don’t understand, and there’s something here that’s larger than a fish, maybe some species that hasn’t been detected before. I don’t know.”^[101]

Searching for the Loch Ness Monster (2003)

In 2003, the BBC sponsored a search of the loch using 600 sonar beams and satellite tracking. The search had sufficient resolution to identify a small buoy. No animal of substantial size was found and, despite their high hopes, the scientists involved admitted that this proved the Loch Ness Monster was a myth. Searching for the Loch Ness Monster aired on BBC One.^[102]

Explanations

A number of explanations have been suggested to account for sightings of the creature. They may be categorised as misidentifications of known animals, misidentifications of inanimate objects or effects, reinterpretations of Scottish folklore, hoaxes, and exotic species of large animals.

Misidentification of known animals

Bird wakes

Wakes have been reported when the loch is calm, with no boats nearby. Bartender David Munro reported a wake he believed was a creature zigzagging, diving, and reappearing; there were reportedly 26 other witnesses from a nearby car park.^{[93][better source needed]} Although some sightings describe a V-shaped wake similar to a boat’s,^[97] others report something not conforming to the shape of a boat.^[50] Under calm conditions, creatures invisible to the naked eye (such as a group of swimming birds) may leave a V-shaped wake. They can leave the water and land again, leaving a series of wakes like an object breaking the surface (which Dick Raynor cites as a possible explanation of his film).^[103]

Eels

A large eel was an early suggestion.^[18] Eels are found in Loch Ness, and an unusually-large one would explain many sightings.^[104] Dinsdale dismissed the hypotheses, because eels undulate side to side like snakes.^[105] Sightings in 1856 of a “sea-serpent” (or kelpie in a freshwater lake near Leurbost in the Outer Hebrides were explained as those of an oversized eel, also believed common in “Highland lakes””^[106]

On 2 May 2001, two conger eels were found on the shore of the loch. Since that fish is a marine species, they were considered a hoax.^[107]

Elephant

In a 1979 article, California biologist Dennis Power and geographer Donald Johnson claimed that the “surgeon’s photograph” was the top of the head, extended trunk and flared nostrils of a swimming elephant photographed elsewhere and claimed to be from Loch Ness.^[41] In 2006, palaeontologist and artist Neil Clark suggested that travelling circuses might have allowed elephants to bathe in the loch; the trunk could be the perceived head and neck, with the head and back the perceived humps. In support of this, Clark provided a painting.^[108]

Greenland shark

Angler and television presenter Jeremy Wade investigated the creature in 2013 as part of the series River Monsters, and concluded that it is a Greenland shark. The Greenland shark, which can reach up to 20 feet in length, inhabits the North Atlantic Ocean around Canada, Greenland, Iceland, Norway, and possibly Scotland. It is dark in colour, with a small dorsal fin.^[109] According to biologist Bruce Wright, the Greenland shark could survive in fresh water (possibly using rivers and lakes to find food) and Loch Ness has an abundance of salmon and other fish.^[110][111]

Wels catfish

In July 2015 three news outlets reported that Steve Feltham, after a vigil at the loch which was recognized by the Guinness Book of Records, theorised that the monster is an unusually-large specimen of Wels catfish (Silurus glanis) which may have been released during the late 19th century.^{[112][113][114]}

Resident animals

It is difficult to judge the size of an object in water through a telescope or binoculars with no external reference. Loch Ness has resident otters, and photos of them and deer swimming in the loch which were cited by author Ronald Binns^[115] may have been misinterpreted. According to Binns, birds may be mistaken for a “head and neck” sighting.^[116]

Seals

During the 1930s, Dutch zoologist Antoon Cornelis Oudemans proposed that the creature might be an unknown form of long-necked pinniped (semi-aquatic mammal, including the seals). In 1892, he concluded that several sightings of sea serpents were probably large, plesiosaur-like pinnipeds and named a hypothetical species of long-necked pinniped Megophias megophias. According to Oudemans, the Loch Ness Monster was a freshwater version of Megophias megophias.^{[citation needed]}

A number of photographs and a video have confirmed the presence of seals in the loch for as long as several months at a time.^[117][118] In 1934 the Edward Mountain expedition analysed film taken that year and concluded that the monster was a species of seal; a Daily Mirror headline read, “Loch Ness Riddle Solved – Official”.^[119] A long-necked seal was hypothesised by Peter Costello for Nessie and for other reported lake monsters.^[120] According to R. T. Gould, “A grey seal has a long and surprisingly extensible neck; it swims with a paddling action; its colour fits the bill; and there is nothing surprising in its being seen on the shore of the loch, or crossing a road.”^[19] This explains sightings of lake monsters on land in which the creature reportedly waddled into the loch when startled, consistent with seal behaviour.^[120] Seals would account for sonar traces of animate objects. However, it has been argued that all known pinnipeds sunbathe on land during the day.^[121]

Misidentifications of inanimate objects or effects

Trees

In 1933, the Daily Mirror published a picture with the caption: “This queerly-shaped tree-trunk, washed ashore at Foyers [on Loch Ness] may, it is thought, be responsible for the reported appearance of a ‘Monster'”.^[122] In a 1982 series of articles for New Scientist, Maurice Burton proposed that sightings of Nessie and similar creatures may be fermenting Scots pine logs rising to the surface of the loch. A decomposing log could not initially release gases caused by decay because of its high resin level. Gas pressure would eventually rupture a resin seal at one end of the log, propelling it through the water (sometimes to the surface). According to Burton, the shape of tree logs (with their branch stumps) closely resembles descriptions of the monster.^{[123][124][125]}

Four Scottish lochs, including Loch Morar, Loch Ness and Loch Lomond, are very deep. Only lochs with pine forests on their shores have monster legends; Loch Lomond, with no such forests, does not. Gaseous emissions and surfactants resulting from log decay can cause the foamy wake reported in some sightings, and beached pine logs showing evidence of deep-water fermentation have been found. However, believers say that some lakes have reports of monsters despite an absence of pines; one example is the Irish lough monsters.^{[126][better source needed]}

Seiches and wakes

Loch Ness, because of its long, straight shape, is subject to unusual ripples affecting its surface. A seiche is a large oscillation of a lake, caused by water reverting to its natural level after being blown to one end of the lake (resulting in a standing wave); the Loch Ness oscillation period is 31.5 minutes.^[127]

Boat wakes can produce strange effects in the loch. As a wake spreads from a boat passing the centre of the loch, it hits both sides almost simultaneously and deflects back to meet in the middle. The movement produces standing waves larger than the original wake, which may appear humped. Since the boat has passed, the unusual waves are all that can be seen.^[128][129]

Optical effects

Wind conditions can give a choppy, matte appearance to the water, with calm patches appearing dark from the shore (reflecting the mountains). In 1979 W. H. Lehn showed that atmospheric refraction could distort the shape and size of objects and animals,^[130] and later published a photograph of a mirage of a rock on Lake Winnipeg which resembled a head and neck.^[131]

Seismic gas

Italian geologist Luigi Piccardi has proposed geological explanations for ancient legends and myths. Piccardi noted that in the earliest recorded sighting of a creature (the Life of Saint Columba), the creature’s emergence was accompanied “cum ingenti fremitu” (“with loud roaring”). The Loch Ness is along the Great Glen Fault, and this could be a description of an earthquake. Many reports consist only of a large disturbance on the surface of the water; this could be a release of gas through the fault, although it may be mistaken for something swimming below the surface.^[132]

According to Ronald Binns, there is probably no one explanation of the monster. A wide range of natural phenomena have been hypothesised, including otters, swimming deer, and unusual waves. Binns wrote that an aspect of human psychology is the ability of the eye to see what it wants, and expects, to see.^[11]

Folklore

In 1980 Swedish naturalist and author Bengt Sjögren wrote that present beliefs in lake monsters such as the Loch Ness Monster are associated with kelpie legends. According to Sjögren, accounts of loch monsters have changed over time; originally describing horse-like creatures, they were intended to keep children away from the loch. Sjögren wrote that the kelpie legends have developed into descriptions reflecting a modern awareness of plesiosaurs..^[133]

The kelpie as a water horse in Loch Ness was mentioned in an 1879 Scottish newspaper,^[134] and inspired Tim Dinsdale‘s Project Water Horse.^[135] A study of pre-1933 Highland folklore references to kelpies, water horses and water bulls indicated that Ness was the loch most frequently cited.^[136]

Hoaxes

A number of hoax attempts have been made, some of which were successful. Other hoaxes were revealed rather quickly by the perpetrators or exposed after diligent research. A few examples follow.

In August 1933, Italian journalist Francesco Gasparini submitted what he said was the first news article on the Loch Ness Monster. In 1959, he reported sighting a “strange fish” and fabricated eyewitness accounts: “I had the inspiration to get hold of the item about the strange fish. The idea of the monster had never dawned on me, but then I noted that the strange fish would not yield a long article, and I decided to promote the imaginary being to the rank of monster without further ado.”^[137]

In the 1930s, big-game hunter Marmaduke Wetherell went to Loch Ness to look for the monster. Wetherell claimed to have found footprints, but when casts of the footprints were sent to scientists for analysis they turned out to be from a hippopotamus; a prankster had used a hippopotamus-foot umbrella stand.^[138]

In 1972 a team of zoologists from Yorkshire’s Flamingo Park Zoo, searching for the monster, discovered a large body floating in the water. The corpse, 4.9–5.4 m (16–18 ft) long and weighing as much as 1.5 tonnes, was described by the Press Association as having “a bear’s head and a brown scaly body with clawlike fins.” The creature was placed in a van to be carried away for testing, but police seized the cadaver under an act of parliament prohibiting the removal of “unidentified creatures” from Loch Ness. It was later revealed that Flamingo Park education officer John Shields shaved the whiskers and otherwise disfigured a bull elephant seal which had died the week before and dumped it in Loch Ness to dupe his colleagues.^{[citation needed]} On 2 July 2003, Gerald McSorely a fossil supposedly from the creature when he tripped and fell into the loch. After examination, it was clear that the fossil had been planted.^[107]

In 2004 a Five TV documentary team, using cinematic special-effects experts, tried to convince people that there was something in the loch. They constructed an animatronic model of a plesiosaur, calling it “Lucy”. Despite setbacks (including Lucy falling to the bottom of the loch), about 600 sightings were reported where she was placed.^[139][140]

In 2005, two students claimed to have found a large tooth embedded in the body of a deer on the loch shore. They publicised the find, setting up a website, but expert analysis soon revealed that the “tooth” was the antler of a muntjac.^[141] The tooth was a publicity stunt to promote a horror novel by Steve Alten, The Loch.^[107]

In 2007, a video reportedly showing Nessie jumping into the air appeared on YouTube. It was unmasked by eSkeptic as an advertisement for Sony Pictures’ The Water Horse,^[142] since the video contained footage from the film.

Exotic large-animal species

Plesiosaur

In 1933 it was suggested that the creature “bears a striking resemblance to the supposedly extinct plesiosaur“,^[143] a long-necked aquatic reptile which became extinct during the Cretaceous–Paleogene extinction event. A popular explanation at the time, the following arguments have been made against it:

• Plesiosaurs were probably cold-blooded reptiles needing warm tropical waters; the average temperature of Loch Ness is only about 5.5 °C (42 °F).^[144] If the plesiosaurs were warm-blooded, they would require a food supply beyond that supplied by Loch Ness.^[145]
• In an October 2006 New Scientist article, “Why the Loch Ness Monster is no plesiosaur”, Leslie Noè of the Sedgwick Museum in Cambridge said: “The osteology of the neck makes it absolutely certain that the plesiosaur could not lift its head up swan-like out of the water”.^[146]
• The loch is only about 10,000 years old, dating to the end of the last ice age. Before then, it was frozen for about 20,000 years.^[147]
• If creatures similar to plesiosaurs lived in Loch Ness they would be seen frequently, since they would have to surface several times a day to breathe.^[100]

In response to these criticisms, Tim Dinsdale, Peter Scott and Roy Mackal postulate a trapped marine creature which evolved from a plesiosaur directly or by convergent evolution.^[148] Robert Rines explained that the “horns” in some sightings as breathing tubes (or nostrils), allowing it to breathe without breaking the surface.

Long-necked giant amphibian

R. T. Gould suggested a long-necked newt;^[19][149] Roy Mackal examined the possibility, giving it the highest score (88 percent) on his list of possible candidates.^[150]

Invertebrate

In 1968 F. W. (Ted) Holiday proposed that Nessie and other lake monsters, such as Morag, may be a large invertebrate such as a bristleworm; he cited the extinct Tullimonstrum as an example of the shape.^[151] According to Holiday, this explains the land sightings and the variable back shape; he likened it to the medieval description of dragons as “worms”. Although this theory was considered by Mackal, he found it less convincing than eels, amphibians or plesiosaurs.^[

 

 

 

 

 

 

 

 

 

 

Quicksand, Sinkholes, Blowouts and the Swallowing up of Devatta / Daywatat ေဒ၀ဒတ္ and Cina Manakiva / Zeinzamarna ဇိဥၨမာန by the earth ေျမျမိဳခံရျခင္း

Of the Eight Glorious Victories of Buddha ေအာင္ျခင္း ၈ ပါး are (3) the Subduing the fierce elephant, Nalagiri, released by Devadatta, the third Victory တတိယ ေအာင္ျခင္း and (5) Exposing the tricks of the beautiful Cinca Manavika, the fifth Victory ပဥၥမ ေအာင္ျခင္း။

Buddha subduing the drunken fierce man-killer elephant Nalagiri sent by Devadatta

Cinca Manavika making a false accusation against Buddha

Both Devadatta and Cinca Manavika were swallowed up by the earth near the Jevatana / Zatawun monastery ေဇတ၀န္ေက်ာင္း gates for their misdeeds and went down alive to Avici အ၀ီစိ.

Devadatta being swallowed by the earth.

Place near Jevatana / Zatawun monastery ေဇတ၀န္ေက်ာင္း where Devadatta was swallowed by the earth

Place near Jevatana / Zatawun monastery ေဇတ၀န္ေက်ာင္း where Cina Manavika was swallowed by the earth and went alive to Avici အ၀ီစိ.

Devadatta, brother in law and cousin of Buddha, was a misled monk with many followers. He planned to kill Buddha, first by hiring assasins, and when it failed, he himself climbed on the hill near the Vulture’s Rock while Buddha was walking and hurled a a huge stone at Buddha, which, although it missed, struck another rock and a splinter wounded Buddha’s foot. His third attempt, using the fierce man-killer elephant Nalagiri after making it drunk with liquor also failed when Buddha‘s loving kindness conquered it.

The Vulture’s Rock / Gigzagote hill ဂဇၨဂုတ္ေတာင္ where Buddha resided and meditated during His stay in Rajgir / Yarzagyo ရာဇျဂိဳလ္

Devadatta pushing a stone from the hill near the Vulture’s Rock while Buddha was walking beneath

< Devadatta>

Devadatta’s third attempt on Buddha, using the fierce man-killer elephant Nalagiri after making it drunk with liquor

The hill near the Vulture’s Rock / Gigzagote hill ဂဇၨဂုတ္ေတာင္ from which Devadatta pushed a stone down on Buddha

Cina Manavika is a paribbajika of some ascetic Order. She was very beautiful and was enlisted by the heretics of this Order in their attempt to discredit Buddha as their gains were getting less. She pretended to pay visits to Buddha at Jetavana and after some time, simulated pregnancy and appeared before Buddha as He was preaching to a large congregation. She falsely accused Him of being the cause of her pregnancy in front of others.

< Cinca Manavika life-of-buddha-46>

Buddha, without refuting, said that only she and He know the truth. Sakka သိၾကားမင္း, king of the devas နတ္, came to the rescue by sendning four of his devas in form of rats to cut the cords of the wooden disc (or cloth in another version) which is used to feign pregnancy. It fell down and her deception was established and she ran away and was swallowed up by the earth nearby.

The swallowing up of people by the earth ေျမျမိဳခံရျခင္း  has been mentioned in Buddhawin and Myanmar folklore and even in present day period such an incident was reported in Thanlyin not so long ago. However, apart from quick sand, which is a naturally occuring phenomenon, the occurences in Buddhawin are said to occur on firm ground as a supernatural phenomenon.

A sinkhole, also known as a sink, snake hole, swallow hole, swallet, doline, or cenote, is a natural depression or hole in the Earth’s surface caused by karst processes — for example, the chemical dissolution of carbonate rocks^[1] or suffosion processes^[2] in sandstone. Sinkholes may vary in size from 1 to 600 metres (3.3 to 2,000 ft) both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may be formed gradually or suddenly, and are found worldwide. The different terms for sinkholes are often used interchangeably.

sinkhole

Natural sinkholes have swallowed down even large buildings but large holes are left in the ground.

Natural sinkholes have swallowed down even large buildings but large holes are left in the ground.

Formation mechanisms

Sinkholes near the Dead Sea, formed by dissolution of underground salt by incoming freshwater, as a result of a continuing sea level drop.

A special type of sinkhole, formed by rainwater leaking through the pavement and carrying soil into a ruptured sewer pipe.

Sinkholes may capture surface drainage from running or standing water, but may also form in high and dry places in a certain location.

The mechanisms of formation involve natural processes of erosion^[4] or gradual removal of slightly soluble bedrock (such as limestone) by percolating water, the collapse of a cave roof, or a lowering of the water table. Sinkholes often form through the process of suffosion. Thus, for example, groundwater may dissolve the carbonate cement holding the sandstone particles together and then carry away the lax particles, gradually forming a void.

Also in the oil and gas industry when blowouts occur during drilling, large drilling rigs can be totally swallowed into the earth, even in offshore situations (as with the well documented disappearance of a land rig and even a bigger off shore rig in Myanmar in the not so distant past).

Oil well blowout

Well blowouts can occur during the drilling phase, during well testing, during well completion, during production, or during workover activities.

offshore oil well drilling blowout

In the modern petroleum industry, uncontrollable wells became known as blowouts and are comparatively rare. There has been significant improvement in technology, well control techniques, and personnel training which has helped to prevent their occurring

< P1190898>

Sakka သိၾကားမင္း, king of the devas နတ္, came to the rescue by sendning four of his devas in form of rats to cut the cords of the wooden disc (or cloth in another version) which is used to feign pregnancy.

How Quicksand forms

Quicksand is a colloid hydrogel consisting of fine granular material (such as sand or silt), clay, and water.

Quicksand forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates liquefied soil that loses strength and cannot support weight. Quicksand can be formed in standing water or in upwards flowing water (as from an artesian spring). In the case of upwards flowing water, seepage forces oppose the force of gravity and suspend the soil particles.

The saturated sediment may appear quite solid until a sudden change in pressure or shock initiates liquefaction. This causes the sand to form a suspension and lose strength. The cushioning of water gives quicksand, and other liquefied sediments, a spongy, fluidlike texture. Objects in liquefied sand sink to the level at which the weight of the object is equal to the weight of the displaced soil/water mix and the submerged object floats due to its buoyancy.

Liquefaction is a special case of quicksand. In this case, sudden earthquake forces immediately increases the pore pressure of shallow groundwater. The saturated liquefied soil loses strength, causing buildings or other objects on that surface to sink or fall over.

< P1200009>

The Jetavana monastery in Sravasti of Kosala Kingdom

The swallowing up of both Devadatta and Cinca Manavika occurred near the Jetavana monastery in Sravasti သာ၀တၱိ of Kosala Kingdom.

Modern day Sravasti  သာ၀တၱိ

Sravasti Myanmar monastery သာ၀တၱိ ျမန္မာဘုန္းၾကီးေက်ာင္း

Sravasti was visited and recorded by the Chinese Monk pilgrim, Fa Hien after his travels to India and Sri Lanka (A.D. 399-414) in Search of the Buddhist Books of Discipline (the famous story of Journey to the West by a Tang monk and his four disciples_ Sun Wu Kong et al _was based on Fa Hien’s travels) and he mentioned as follows_ The earth at the same time was rent, and she Chanchamana / Cinca Manavika / Zeinzamana went (down) alive into hell / Avici အ၀ီစိ. (This) also is the place where Devadatta, trying with empoisoned claws to injure Buddha, went down alive into hell. Men subsequently set up marks to distinguish where both these events took place.

Details of the subjects of interest on the topic follows below

• KOSALA AND SRAVASTI. THE JETAVANA VIHARA AND OTHER MEMORIALS AND LEGENDS OF BUDDHA. SYMPATHY OF THE MONKS WITH THE PILGRIMS by Chinese monk Fa Hien
• Devadatta, the Buddha’s Enemy
• Devadatta
• Cinca Manavika

• Cinca Manavika falsely accuses the Buddha
• Quicksand
• How Quicksand Works
• Cause of Florida sinkhole tragedy: Human activity or revenge of the karst?
• Sinkhole

• Blowout (well drilling)

Record of Buddhist Kingdoms by Chinese Monk, Fa Hien

Being an Account by the Chinese Monk Fa-Hien of his Travels in India and Ceylon (A.D. 399-414) in Search of the Buddhist Books of Discipline

CHAPTER XX

KOSALA AND SRAVASTI. THE JETAVANA VIHARA AND OTHER MEMORIALS AND LEGENDS OF BUDDHA. SYMPATHY OF THE MONKS WITH THE PILGRIMS

< P1200017>

< P1200032>

Going on from this to the south, for eight yojanas, (the travellers) came to the city of Sravasti[1] in the kingdom of Kosala,[2] in which the inhabitants were few and far between, amounting in all (only) to a few more than two hundred families; the city where king Prasenajit[3] ruled, and the place of the old vihara of Maha-prajapti;[4] of the well and walls of (the house of) the (Vaisya) head Sudatta;[5] and where the Angulimalya[6] became an Arhat, and his body was (afterwards) burned on his attaining to pari-nirvana. At all these places topes were subsequently erected, which are still existing in the city. The Brahmans, with their contrary doctrine, became full of hatred and envy in their hearts, and wished to destroy them, but there came from the heavens such a storm of crashing thunder and flashing lightning that they were not able in the end to effect their purpose.

As you go out from the city by the south gate, and 1,200 paces from it, the (Vaisya) head Sudatta built a vihara, facing the south; and when the door was open, on each side of it there was a stone pillar, with the figure of a wheel on the top of that on the left, and the figure of an ox on the top of that on the right. On the left and right of the building the ponds of water clear and pure, the thickets of trees always luxuriant, and the numerous flowers of various hues, constituted a lovely scene, the whole forming what is called the Jetavana vihara.[7]

< P1200010>

The Jetavana vihara was originally of seven storeys. The kings and people of the countries around vied with one another in their offerings, hanging up about it silken streamers and canopies, scattering flowers, burning incense, and lighting lamps, so as to make the night as bright as the day. This they did day after day without ceasing. (It happened that) a rat, carrying in its mouth the wick of a lamp, set one of the streamers or canopies on fire, which caught the vihara, and the seven storeys were all consumed. The kings, with their officers and people, were all very sad and distressed, supposing that the sandal-wood image had been burned; but lo! after four or five days, when the door of a small vihara on the east was opened, there was immediately seen the original image. They were all greatly rejoiced, and co-operated in restoring the vihara. When they had succeeded in completing two storeys, they removed the image back to its former place.

< P1200023>

When Fa-hien and Tao-ching first arrived at the Jetavana monastery, and thought how the World-honoured one had formerly resided there for twenty-five years, painful reflections arose in their minds. Born in a border-land, along with their like-minded friends, they had travelled through so many kingdoms; some of those friends had returned (to their own land), and some had (died), proving the impermanence and uncertainty of life; and to-day they saw the place where Buddha had lived now unoccupied by him. They were melancholy through their pain of heart, and the crowd of monks came out, and asked them from what kingdom they were come. “We are come,” they replied, “from the land of Han.” “Strange,” said the monks with a sigh, “that men of a border country should be able to come here in search of our Law!” Then they said to one another, “During all the time that we, preceptors and monks,[11] have succeeded to one another, we have never seen men of Han, followers of our system, arrive here.”

< 5 exposing the tricks of the beautiful Cinca-Manavika>

Outside the east gate of the Jetavana, at a distance of seventy paces to the north, on the west of the road, Buddha held a discussion with the (advocates of the) ninety-six schemes of erroneous doctrine, when the king and his great officers, the householders, and people were all assembled in crowds to hear it. Then a woman belonging to one of the erroneous systems, by name Chanchamana,[15] prompted by the envious hatred in her heart, and having put on (extra) clothes in front of her person, so as to give her the appearance of being with child, falsely accused Buddha before all the assembly of having acted unlawfully (towards her). On this, Sakra, Ruler of Devas, changed himself and some devas into white mice, which bit through the strings about her waist; and when this was done, the (extra) clothes which she wore dropt down on the ground. The earth at the same time was rent, and she went (down) alive into hell.[16] (This) also is the place where Devadatta,[17] trying with empoisoned claws to injure Buddha, went down alive into hell. Men subsequently set up marks to distinguish where both these events took place.

There are also companies of the followers of Devadatta still existing. They regularly make offerings to the three previous Buddhas, but not to Sakyamuni Buddha.

NOTES

[1] In Singhalese, Sewet; here evidently the capital of Kosala. It is placed by Cunningham (Archaeological Survey) on the south bank of the Rapti, about fifty-eight miles north of Ayodya or Oude. There are still the ruins of a great town, the name being Sahet Mahat. It was in this town, or in its neighbourhood, that Sakyamuni spent many years of his life after he became Buddha.

[2] There were two Indian kingdoms of this name, a southern and a northern. This was the northern, a part of the present Oudh.

In Singhalese, Pase-nadi, meaning “leader of the victorious army.” He was one of the earliest converts and chief patrons of Sakyamuni. Eitel calls him (p. 95) one of the originators of Buddhist idolatory, because of the statue which is mentioned in this chapter. See Hardy’s

B., pp. 283, 284, et al.

[4] Explained by “Path of Love,” and “Lord of Life.” Prajapati was aunt and nurse of Sakyamuni, the first woman admitted to the monkhood, and the first superior of the first Buddhistic convent. She is yet to become a Buddha.

[5] Sudatta, meaning “almsgiver,” was the original name of Anatha­pindika (or Pindada), a wealthy householder, or Vaisya head, of Sravasti, famous for his liberality (Hardy, Anepidu). Of his old house, only the well and walls remained at the time of Fa-hien’s visit to Sravasti.

[6] The Angulimalya were a sect or set of Sivaitic fanatics, who made assassination a religious act. The one of them here mentioned had joined them by the force of circumstances. Being converted by Buddha, he became a monk; but when it is said in the text that he “got the Tao,” or doctrine, I think that expression implies more than his conversion, and is equivalent to his becoming an Arhat. His name in Pali is Angulimala. That he did become an Arhat is clear from his autobiographical poem in the “Songs of the Theras.”

[7] Eitel (p. 37) says:–“A noted vihara in the suburbs of Sravasti, erected in a park which Anatha-pindika bought of prince Jeta, the son of Prasenajit. Sakyamuni made this place his favourite residence for many years. Most of the Sutras (authentic and supposititious) date from this spot.”

[11] This is the first time that Fa-hien employs the name Ho-shang {.} {.}, which is now popularly used in China for all Buddhist monks without distinction of rank or office. It is the representative of the Sanskrit term Upadhyaya, “explained,” says Eitel (p. 155) by “a self-taught teacher,” or by “he who knows what is sinful and what is not sinful,” with the note, “In India the vernacular of this term is {.} {.} (? munshee [? Bronze]); in Kustana and Kashgar they say {.} {.} (hwa-shay); and from the latter term are derived the Chinese synonyms, {.} {.} (ho-shay) and {.} {.} (ho-shang).” The Indian term was originally a designation for those who teach only a part of the Vedas, the Vedangas. Adopted by Buddhists of Central Asia, it was made to signify the priests of the older ritual, in distinction from the Lamas. In China it has been used first as a synonym for {.} {.}, monks engaged in popular teaching (teachers of the Law), in distinction from {.} {.}, disciplinists, and {.} {.}, contemplative philosophers (meditationists); then it was used to designate the abbots of monasteries. But it is now popularly applied to all Buddhist monks. In the text there seems to be implied some distinction between the “teachers” and the “ho-shang;”–probably, the Pali Akariya and Upagghaya; see Sacred Books of the East, vol. xiii, Vinaya Texts, pp. 178, 179.

[15] Eitel (p. 144) calls her Chancha; in Singhalese, Chinchi. See the story about her, M. B., pp. 275-277.

[16] “Earth’s prison,” or “one of Earth’s prisons.” It was the Avichi naraka to which she went, the last of the eight hot prisons, where the culprits die, and are born again in uninterrupted succession (such being the meaning of Avichi), though not without hope of final redemption. E. H. p. 21.

[17] Devadatta was brother of Ananda, and a near relative therefore of Sakyamuni. He was the deadly enemy, however, of the latter. He had become so in an earlier state of existence, and the hatred continued in every successive birth, through which they reappeared in the world. See the accounts of him, and of his various devices against Buddha, and his own destruction at the last, in M. B., pp. 315-321, 326-330; and still better, in the Sacred Books of the East, vol. xx, Vinaya Texts, pp. 233-265. For the particular attempt referred to in the text, see “The Life of the Buddha,” p. 107. When he was engulphed, and the flames were around him, he cried out to Buddha to save him, and we are told that he is expected yet to appear as a Buddha under the name of Devaraja, in a universe called Deva-soppana. E. H., p. 39.

 

Devadatta, the Buddha’s Enemy

http://www.buddhanet.net/e-learning/buddhism/lifebuddha/2_5lbud.htm

Devadatta was the son of King Suppabuddha and his wife Pamita, who was an aunt of the Buddha. Devadatta’s sister was Yasodhara, making him both a cousin and brother-in-law of the Buddha. Together with Ananda and other Sakyan princes, he entered the order of monks in the early part of the Buddha’s ministry, but was unable to attain any stage of sainthood and so worked hard for the worldly psychic powers.

In his early days, he was a good monk known for his grace and psychic powers. Later he became conceited with worldly gain and fame. As his ill-will and jealousy towards the Buddha increased, he became the greatest personal enemy of the Buddha.

One day in a large assembly, which included kings and princes, Devadatta approached the Buddha and asked him to make him the leader of the Sangha. Since he was not capable and worthy enough, the Buddha turned down this request. Devadatta became very angry as a result and vowed to take revenge on the Buddha.

Although Devadatta was an evil monk, he had many admirers and followers. One of his chief supporters was King Ajatasattu, with whom he discussed his anger and plots for revenge. Together they planned to kill King Ajatasattu’s father and rival, King Bimbisara and Devadatta’s enemy, the Buddha. Ajatasattu succeeded in killing his father, but Devadatta failed to kill the Buddha.

His first attempt to kill the Buddha was to hire a man to kill the Blessed One. The plan was that the man be killed by two other men who would in turn be killed by four other men. Finally the four men would be killed by eight other men. But when the first man came close to the Buddha, he became frightened. He put aside his weapons and took refuge in the Buddha. Eventually all the men who were hired to kill one another became disciples of the Buddha and the cunning plan failed.

Then Devadatta himself tried to kill the Buddha. When the Buddha was walking on the Vultures’ Rock, Devadatta climbed to the peak and hurled a huge stone at the Buddha. On its way down, the rock struck another rock and a splinter flew and wounded the Buddha’s foot, causing blood to flow. The Buddha looked up and seeing Devadatta, he remarked with pity, “Foolish man, you have done many unwholesome deeds for harming the Buddha.”

Devadatta’s third attempt to kill the Blessed One was to make the fierce man-killer elephant, Nalagiri, drunk with liquor. When Nalagiri saw the Buddha coming at a distance, it raised its ears, tail and trunk and charged at him. As the elephant came close, the Buddha radiated his loving-kindness (metta) towards the elephant. So vast and deep was the Buddha’s love that as the elephant reached the Buddha, it stopped, became quiet and stood before the Master. The Buddha then stroked Nalagiri on the trunk and spoke softly. Respectfully, the elephant removed the dust at the master’s feet with its trunk, and scattered the dust over its own head. Then it retreated, with its head facing the Buddha, as far as the stable, and remained fully tamed. Usually elephants are tamed with whips and weapons, but the Blessed One tamed the elephant with the power of his loving-kindness.

Still trying to be the leader of the Sangha, Devadatta tried yet another plan — a deceitful one. With the help of five hundred misled monks, he planned to split the Sangha community.

He requested the Buddha to make it compulsory for monks to follow five extra rules:

(i) Dwell all their lives in the forest
(ii) Live only on alms obtained by begging
(iii) Wear robes made from rags collected from the dust heaps and cemeteries
(iv) Live at the foot of trees
(v) Refrain from eating fish or meat throughout their lives.

Devadatta made this request, knowing full well that the Buddha would refuse it. Devadatta was happy that the Buddha did not approve of the five rules, and he used these issues to gain supporters and followers. Newly ordained monks who did not know the Dharma well left the Buddha and accepted Devadatta as their leader. Eventually, after Venerable Sariputta and Venerable Moggallana had explained the Dharma to them, they went back to the Buddha.

After this, evil days fell on Devadatta. He fell very ill at the failure of his plans, and before his death he sincerely regretted his actions, and wanted to see the Buddha before he died. But the fruits of his evil karma had begun to ripen and prevented him from doing so. He grew desperately ill on the way to see the Buddha, near the gate of Jetavana monastery. But before he died he took refuge in the Buddha.

Although he has to suffer in a woeful state because of his crimes, the holy life he led in the early part of his career ensured that Devadatta would become a Pacceka Buddha named Atthissara in the distant future. As a Pacceka Buddha he would be able to achieve Enlightenment by his own efforts.

Devadatta

http://www.buddhanet.net/e-learning/buddhism/bud_lt28.htm

A striking example of this mental attitude is seen in his relation with Devadatta. Devadatta was a cousin of the Buddha who entered the Order and gained supernormal powers of the mundane plane (puthujjana-iddhi). Later, however, he began to harbour thoughts of jealousy and ill will toward his kinsman, the Buddha, and his two chief disciples, Sâriputta and Mahâ Moggallâna, with the ambition of becoming the leader of the Sangha, the Order of Monks.

Devadatta wormed himself into the heart of Ajâtasattu, the young prince, the son of King Bimbisâra. One day when the Blessed One was addressing a gathering at the Veluvana Monastery, where the king, too, was present, Devadatta approached the Buddha, saluted him, and said: “Venerable sir, you are now enfeebled with age. May the Master lead a life of solitude free from worry and care. I will direct the Order.”

The Buddha rejected this overture and Devadatta departed irritated and disconcerted, nursing hatred and malice toward the Blessed One. Then, with the malicious purpose of causing mischief, he went to Prince Ajâtasattu, kindled in him the deadly embers of ambition, and said:

“Young man, you had better kill your father and assume kingship lest you die without becoming the ruler. I shall kill the Blessed One and become the Buddha.”

So when Ajâtasattu murdered his father and ascended the throne Devadatta suborned ruffians to murder the Buddha, but failing in that endeavour, he himself hurled down a rock as the Buddha was climbing up Gijjhakûta Hill in Râjagaha. The rock tumbled down, broke in two, and a splinter slightly wounded the Buddha. Later Devadatta made an intoxicated elephant charge at the Buddha; but the animal prostrated himself at the Master’s feet, overpowered by his loving-kindness. Devadatta now proceeded to cause a schism in the Sangha, but this discord did not last long. Having failed in all his intrigues, Devadatta retired, a disappointed and broken man. Soon afterwards he fell ill, and on his sick-bed, repenting his follies, he desired to see the Buddha. But that was not to be; for he died on the litter while being carried to the Blessed One. Before his death, however, he uttered repentance and sought refuge in the Buddha.

Cinca Manavika, 1 Definition(s)

http://www.wisdomlib.org/definition/cinca-manavika/index.html

A paribbajika of some ascetic Order. When the heretics of this Order found that their gains were grown less owing to the popularity of the Buddha, they enlisted the support of Cinca in their attempts to discredit him. She was very beautiful and full of cunning, and they persuaded her to pretend to pay visits to the Buddha at Jetavana. She let herself be seen going towards the vihara in the evening, spent the night in the heretics quarters near by, and in the morning men saw her returning from the direction of the vihara. When questioned, she said that she had passed the night with the Buddha. After some months she simulated pregnancy by tying a disc of wood round her body and appearing thus before the Buddha, as he preached to a vast congregation, she charged him with irresponsibility and callousness in that he made no provision for her confinement. The Buddha remained silent, but Sakkas throne was heated and he caused a mouse to sever the cords of the wooden disc, which fell to the ground, cutting Cincas toes. She was chased out of the vihara by those present, and as she stepped outside the gate the fires of the lowest hell swallowed her up (DhA.iii.178f; J.iv.187f; ItA.69).

XIII:9 Cinca Manavika falsely accuses the Buddha

http://suttanta.tripod.com/khuddhaka/dhammapada/dha144.html

As the Buddha went on expounding the Dhamma, more and more people came flocking to him, and the ascetics of other faiths found their following to be dwindling. So they decided to ruin the reputation of the Buddha. They instigated Cinca Manavika, a beautiful pupil of theirs, and told her, ‘If you have our interests at heart, please help us and put the Buddha to shame.’ She agreed to their plot.

That same evening, she took some flowers and went in the direction of the Jetavana monastery. When people asked her where she was going, she replied, ‘What is the use of you knowing where I am going?’ Then she would go to the place of the other ascetics near the Jetavana monastery and would come back early in the morning to make it appear as if she had spent the night at the Jetavana monastery. When asked, she would reply, ‘I spent the night with the Buddha at the monastery.’ After three or four months had passed, she wrapped some cloth around her stomach to make herself look pregnant. Then, after nine months, she created the impression of a woman in an advanced stage of pregnancy and she went to the monastery to confront the Buddha.

The Buddha was then expounding the Dhamma to a congregation of bhikkhus and laymen. Seeing him preaching she accused him, ‘O you big Samana! You are clever to preach to others. I am now pregnant by you, yet you do nothing for my confinement. You only know how to enjoy yourself!’ The Buddha stopped preaching for a while and said to her, ‘Sister, only you and I know whether you are speaking the truth or not,’ and she replied, ‘Yes, you are right, how can others know what only you and I have done?’

At that instant, Sakka, king of the devas became aware of the trouble taking place at the Jetavana monastery. So he sent four of his devas in the form of young rats, who got under her clothes and bit off the strings that held the cloth around her belly. Thus, her deception was uncovered, and many from the crowd reprimanded her, ‘O you wicked woman! Liar and cheat! How dare you accuse our noble Teacher!’ Fearing for her safety, she ran from the monastery as fast as she could. However after some distance she met with an unfortunate accident and had to face a miserable and untimely death.

The next day, while the bhikkhus were talking about Cinca Manavika, the Buddha told them ‘Bhikkhus, one who is not afraid to tell lies, and who does not care what happens in the future existences, will not hesitate to do any evil.’

The Buddha then revealed that Cinca Manavika in one of her past existences was born as the chief consort to a King. She fell in love with the King’s son but the Prince did not reciprocate her love. So she conceived an evil plan to harm him. She disfigured her body with her own hands. Then she went to the King and falsely accused that his son had done this to her when she refused his advances.

Without investigating, the King banished him from his kingdom. When the King came to know of the true situation, she was duly punished for her evil deeds.

Quicksand

From Wikipedia, the free encyclopedia

This article is about the geological feature. For other uses, see Quicksand (disambiguation).

http://en.wikipedia.org/wiki/Quicksand

Quicksand and warning sign at a gravel quarry.

Quicksand is a colloid hydrogel consisting of fine granular material (such as sand or silt), clay, and water.

Quicksand forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates liquefied soil that loses strength and cannot support weight. Quicksand can be formed in standing water or in upwards flowing water (as from an artesian spring). In the case of upwards flowing water, seepage forces oppose the force of gravity and suspend the soil particles.

The saturated sediment may appear quite solid until a sudden change in pressure or shock initiates liquefaction. This causes the sand to form a suspension and lose strength. The cushioning of water gives quicksand, and other liquefied sediments, a spongy, fluidlike texture. Objects in liquefied sand sink to the level at which the weight of the object is equal to the weight of the displaced soil/water mix and the submerged object floats due to its buoyancy.

Liquefaction is a special case of quicksand. In this case, sudden earthquake forces immediately increases the pore pressure of shallow groundwater. The saturated liquefied soil loses strength, causing buildings or other objects on that surface to sink or fall over.

Contents 1 Properties 2 Prevalence 3 In fiction 4 In music 5 See also 6 References 7 External links

Properties

Quicksand is a non-Newtonian fluid: when undisturbed, it often appears to be solid (“gel” form), but a minor (less than 1%) change in the stress on the quicksand will cause a sudden decrease in its viscosity (“sol” form). After an initial disturbance — such as a person attempting to walk on it — the water and sand in the quicksand separate and dense regions of sand sediment form; it is because of the formation of these high volume fraction regions that the viscosity of the quicksand seems to decrease suddenly. Someone stepping on it will start to sink. To move within the quicksand, a person or object must apply sufficient pressure on the compacted sand to re-introduce enough water to liquefy it. The forces required to do this are quite large: to remove a foot from quicksand at a speed of .01 m/s would require the same amount of force as “that needed to lift a medium-sized car.”^[1]

Because of the higher density of the quicksand, it would be impossible for a human or animal to completely sink in the quicksand, though natural hazards present around the quicksand would lead people to believe that quicksand is dangerous. In actuality the quicksand is harmless on its own, but because it greatly impedes human locomotion, the quicksand would allow harsher elements like solar radiation, dehydration, carnivores, hypothermia or tides to harm a trapped person.^[2]

The way to escape is to wiggle the legs as slowly as possible in order to reduce viscosity, to try spreading the arms and legs far apart and lying supine to increase the body’s surface area, which should allow one to float.^[3]

Prevalence

Quicksand may be found inland (on riverbanks, near lakes, or in marshes), or near the coast.

In fiction

People falling into (and, unrealistically, being submerged in) quicksand or a similar substance is a trope of adventure fiction, notably movies. According to Slate, this gimmick had its heyday in the 1960s, when almost 3% of all films showed someone sinking in mud, sand, or clay, but it has since fallen out of use. The proliferation of quicksand scenes in movies has given rise to an internet subculture scene dedicated to the topic.^[4]

In music

Pete Seeger‘s song “Waist Deep in the Big Muddy” mentions someone drowning after getting stuck in quicksand.

See also

• Dry quicksand
• Muck

References

1. ^ Khaldoun, A., E. Eiser, G. H. Wegdam, and Daniel Bonn. 2005. “Rheology: Liquefaction of quicksand under stress.” Nature 437 (29 Sept.): 635. doi:10.1038/437635a
2. ^ Discovery Channel. MythBusters. Season 2. “Killer Quicksand.” October 20, 2004.
3. ^ Bakalarfor, Nicholas (September 28, 2005). “Quicksand Science: Why It Traps, How to Escape”. National Geographic News. http://news.nationalgeographic.com/news/2005/09/0928_050928_quicksand.html. Retrieved October 9, 2011.
4. ^ Engber, Daniel (23 August 2010). “Terra Infirma: The rise and fall of quicksand.”. Slate. http://www.slate.com/id/2264312/. Retrieved 23 August 2010.

How Quicksand Works

by Kevin Bonsor

http://science.howstuffworks.com/environmental/earth/geology/quicksand.htm

With quicksand, the more you struggle in it the faster you will sink. If you just relax, your body will float in it because your body is less dense than the quicksand.

How many times have you watched a movie where the hero is sucked down into a pit of quicksand, only to be saved at the last minute by grabbing a nearby tree branch and pulling himself out?

If you believed what you saw in movies, you might think that quicksand is a living creature that can suck you down into a bottomless pit, never to be heard from again. But no — the actual properties of quicksand are not quite those portrayed in the movies.

Quicksand is not quite the fearsome force of nature that you sometimes see on the big screen. In fact, the treacherous grit is rarely deeper than a few feet.

It can occur almost anywhere if the right conditions are present. Quicksand is basically just ordinary sand that has been so saturated with water that the friction between sand particles is reduced. The resulting sand is a mushy mixture of sand and water that can no longer support any weight.

If you step into quicksand, it won’t suck you down. However, your movements will cause you to dig yourself deeper into it. In this article, you will learn just how quicksand forms, where it’s found and how you can escape its clutches if you find yourself hip-deep in it.

Next, we’ll find out how the ground shaking beneath your feet can lead to sand slipping beneath your weight. So head to the next page — quick.

What’s Quicksand?

Quicksand is an interesting natural phenomenon — it is actually solid ground that has been liquefied by a saturation of water. The “quick” refers to how easily the sand shifts when in this semiliquid state.

Quicksand is not a unique type of soil; it is usually just sand or another type of grainy soil. Quicksand is nothing more than a soupy mixture of sand and water. It can occur anywhere under the right conditions, according to Denise Dumouchelle, geologist with the United States Geological Survey (USGS).

Quicksand is created when water saturates an area of loose sand and the ordinary sand is agitated. When the water trapped in the batch of sand can’t escape, it creates liquefied soil that can no longer support weight. There are two ways in which sand can become agitated enough to create quicksand:

• Flowing underground water – The force of the upward water flow opposes the force of gravity, causing the granules of sand to be more buoyant.
• Earthquakes – The force of the shaking ground can increase the pressure of shallow groundwater, which liquefies sand and silt deposits. The liquefied surface loses strength, causing buildings or other objects on that surface to sink or fall over.

Vibration tends to enhance the quickness, so what is reasonably solid initially may become soft and then quick, according to Dr. Larry Barron of the New South Wales Geological Survey.

The vibration plus the water barrier reduces the friction between the sand particles and causes the sand to behave like a liquid. To understand quicksand, you have to understand the process of liquefaction. When soil liquefies, as with quicksand, it loses strength and behaves like a viscous liquid rather than a solid, according to the Utah Geological Survey. Liquefaction can cause buildings to sink significantly during earthquakes.

While quicksand can occur in almost any location where water is present, there are certain locations where it’s more prevalent. Places where quicksand is most likely to occur include:

• Riverbanks
• Beaches
• Lake shorelines
• Near underground springs
• Marshes

The next time you’re at the beach, notice the difference in the sand as you stand on different parts of the beach that have varying levels of moisture. If you stand on the driest part of the beach, the sand holds you up just fine. The friction between the sand particles creates a stable surface to stand on.

If you move closer to the water, you’ll notice that the sand that is moderately wet is even more tightly packed than the dry sand. A moderate amount of water creates the capillary attraction that allows sand particles to clump together. This is what allows you to build sand castles.

But beach sand could easily become quicksand if enough water were thrust up through it. If an excessive amount of water flows through the sand, it forces the sand particles apart. This separation of particles causes the ground to loosen, and any mass on the sand will begin to sink through it. In the next section, you will find out how to save yourself if you happen to fall into a pit of quicksand.

http://science.howstuffworks.com/environmental/earth/geology/quicksand2.htm

With quicksand, the more you struggle in it the faster you will sink. If you just relax, your body will float in it because your body is less dense than the quicksand.

If you ever find yourself in a pit of quicksand, don’t worry — it’s not going to swallow you whole, and it’s not as hard to escape from as you might think.

The human body has a density of 62.4 pounds per cubic foot (1 g/cm³) and is able to float on water. Quicksand is denser than water — it has a density of about 125 pounds per cubic foot (2 g/cm³) — which means you can float more easily on quicksand than on water. The key is to not panic. Most people who drown in quicksand, or any liquid for that matter, are usually those who panic and begin flailing their arms and legs.

It may be possible to drown in quicksand if you were to fall in over your head and couldn’t get your head back above the surface, although it’s rare for quicksand to be that deep. Most likely, if you fall in, you will float to the surface. However, the sand-to-water ratio of quicksand can vary, causing some quicksand to be less buoyant.

“By the same token, if the quicksand were deep, as in up to your waist, it would be very difficult to extract yourself from a dense slurry, not unlike very wet concrete,” said Rick Wooten, senior geologist for Engineering Geology and Geohazards for the North Carolina Geological Survey. “The weight of the quicksand would certainly make it difficult to move if you were in above your knees.”

The worst thing to do is to thrash around in the sand and move your arms and legs through the mixture. You will only succeed in forcing yourself farther down into the liquid sandpit. The best thing to do is to make slow movements and bring yourself to the surface, then just lie back. You’ll float to a safe level.

“When someone steps in the quicksand, their weight causes them to sink, just as they would if they stepped in a pond,” Dumouchelle said. “If they struggle, they’ll tend to sink. But, if they relax and try to lay on their back, they can usually float and paddle to safety.”

When you try pulling your leg out of quicksand, you are working against a vacuum left behind by the movement, according to The Worst-Case Scenario Survival Handbook. The authors of the book advise you to move as slowly as possible in order to reduce viscosity. Also, try spreading your arms and legs far apart and leaning over to increase your surface area, which should allow you to float.

While quicksand remains the hackneyed convention of bad adventure movies, there’s very little to be afraid of in real life. As long as you keep a cool head in the situation, the worst result will be a shoe full of wet sand.

Cause of Florida sinkhole tragedy: Human activity or revenge of the karst?

One of the most heavily developed states is also one of the most geologically hazardous – two facts that are not mutually exclusive in creating dangerous sinkholes.

By Patrik Jonsson, Staff writer / March 2, 2013

http://www.csmonitor.com/USA/2013/0302/Cause-of-Florida-sinkhole-tragedy-Human-activity-or-revenge-of-the-karst?nav=634537-csm_article-mostViewed

ATLANTA

The news of a man being swallowed up by the earth as he slept in his Seffner, Fla., house seemed shocking precisely because it was so unusual: Only three men, two of them well drillers, are known to have ever died from a sudden sinkhole in Florida.

Yet the tragic series of events that began Thursday as a 30-foot hole swallowed Jeff Bush as he slept and continues Saturday as rescue crews tiptoe around an “extremely unstable” house also highlights just how geologically hazardous the Sunshine State is, and how human activities have likely increased the number of sinkholes – essentially geological plumbing breaks as the ceilings of carved-out limestone caverns buckle.

Within a mile of Mr. Bush’s home, which apparently sits atop a 100-foot-wide cavern, are 16 verified sinkholes, compared to over 15,000 known sinkholes throughout the state.

Known as a “karst” landscape, Florida, which was once part of the seafloor, sits on a vast limestone bed cratered with caverns dug out over eons of tidal and chemical weathering. About 10 percent of the earth’s landmass is karst, meaning land shaped by eroding bedrock.

RECOMMENDED: Think you know the US? Take our geography quiz.

“What feels capricious to those above is the toll of an active planet, one of those improbable collisions of a human timescale and a geological one,” writes the Atlantic’s Rebecca Rosen on Friday.

Thursday night’s sinkhole drama did not fit the usual progression of dissolving karst, however. Sinkholes usually collapse in slow motion. Walls crack, strain, and complain as the earth begins to slowly give way under a house. In the vast majority of cases, residents have enough time to gather valuables and evacuate the premises.

“Losing a house to a sinkhole is very common, losing life is uncommon,” says retired University of Florida geologist Tony Randazzo. “Most people will have some warning of the pending doom or catastrophic collapse. But there apparently were no warning signs of what happened at the Bush house. That would be very scary.”

Witnesses said the house jarred suddenly, and then they heard yells from a bedroom. Jeff Bush’s brother, Jeremy Bush, ran to the hole, jumped in and began digging for his brother.

“I heard my brother screaming,” Bush told reporters.  “So I ran back there and tried going inside his room.”

A responding deputy told ABC News what he saw as he entered the panicked premises.

“When I turned in the bedroom the only thing that I saw was a hole, and the hole took the entire bedroom,” Hillsborough County Sheriff’s Deputy Douglas Duvall told a local ABC News affiliate. “You could see the bed frame, the dresser. Everything was sinking.”

Mr. Duvall yelled to Jeremy Bush that the house was still collapsing and to get out of the hole. He reached in and pulled a stunned Mr. Bush out.

Changes in drainage due to construction or agricultural irrigation have been known to activate mass outbreaks of sinkholes, where dozens of sinkholes can suddenly appear next to drainage wells and farm fields. Drought followed by heavy rains can also instigate sinkholes as heavy, water-logged earth presses down on limestone caves suddenly devoid of buoyant water. The two previous deaths attributed to sinkholes both involved professional well drillers whose activities cracked the top of limestone caverns, causing collapse.

“Humans can [destabilize karst landscapes] by drawing down water tables or irrigate too much, increasing the weight of the mass of materials that sits on top of the void,” says Jonathan Martin, a geologist at the University of Florida, in Gainesville. “Humans can modify the environment” enough to cause sinkholes.

It’s not yet clear what caused the Seffner sinkhole, however, but geologists say the area, which is part of the heavily populated I-4 corridor that crosses Florida’s midriff from Tampa to Daytona, is particularly prone to sinkhole collapses.

Sinkholes affect so many properties in Florida that the legislature in 2011 changed the law to make it harder to claim sinkhole damages.

“Over the years the [sinkhole] costs to insurance companies have been increasing at an extraordinary rate, because the legislature prevented companies from charging rates in line with the risk,” says Mr. Randazzo. “It finally reached the point where the insurance companies won the day and got the legislature to change the law, significantly weakening the sinkhole protections in the state of Florida.”

Sinkhole

From Wikipedia, the free encyclopedia

Jump to: navigation, search

For the War of 1812 battle, see Battle of the Sink Hole. For a hole in a sink, see Drain (plumbing). For a Sinkhole Server or Internet Sinkhole, see DNS_Sinkhole.

http://en.wikipedia.org/wiki/Sinkhole

Bahmah Sinkhole in Oman

The Devil’s Hole sinkhole near Hawthorne, Florida, USA.

A sinkhole, also known as a sink, snake hole, swallow hole, swallet, doline, or cenote, is a natural depression or hole in the Earth’s surface caused by karst processes — for example, the chemical dissolution of carbonate rocks^[1] or suffosion processes^[2] in sandstone. Sinkholes may vary in size from 1 to 600 metres (3.3 to 2,000 ft) both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may be formed gradually or suddenly, and are found worldwide. The different terms for sinkholes are often used interchangeably.^[3]

Contents 1 Formation mechanisms 2 Occurrence 3 Local names of sinkholes 4 Piping pseudokarst 5 Notable sinkholes 6 See also 7 References 8 External links

Formation mechanisms

Sinkholes near the Dead Sea, formed by dissolution of underground salt by incoming freshwater, as a result of a continuing sea level drop.

A special type of sinkhole, formed by rainwater leaking through the pavement and carrying soil into a ruptured sewer pipe.

Sinkholes may capture surface drainage from running or standing water, but may also form in high and dry places in a certain location.

The mechanisms of formation involve natural processes of erosion^[4] or gradual removal of slightly soluble bedrock (such as limestone) by percolating water, the collapse of a cave roof, or a lowering of the water table. Sinkholes often form through the process of suffosion. Thus, for example, groundwater may dissolve the carbonate cement holding the sandstone particles together and then carry away the lax particles, gradually forming a void.

Occasionally a sinkhole may exhibit a visible opening into a cave below. In the case of exceptionally large sinkholes, such as the Minyé sinkhole in Papua New Guinea or Cedar Sink at Mammoth Cave National Park in Kentucky, a stream or river may be visible across its bottom flowing from one side to the other.

Sinkholes are common where the rock below the land surface is limestone or other carbonate rock, salt beds, or rocks that can naturally be dissolved by circulating ground water. As the rock dissolves, spaces and caverns develop underground. These sinkholes can be dramatic, because the surface land usually stays intact until there is not enough support. Then, a sudden collapse of the land surface can occur.

Sinkholes also form from human activity, such as the rare but still occasional collapse of abandoned mines in places like Louisiana. More commonly, sinkholes occur in urban areas due to water main breaks or sewer collapses when old pipes give way. They can also occur from the overpumping and extraction of groundwater and subsurface fluids. They can also form when natural water-drainage patterns are changed and new water-diversion systems are developed. Some sinkholes form when the land surface is changed, such as when industrial and runoff-storage ponds are created; the substantial weight of the new material can trigger an underground collapse of supporting material, thus causing a sinkhole.

Occurrence

Sinkholes are frequently linked with karst landscapes. In such regions, there may be hundreds or even thousands of sinkholes in a small area so that the surface as seen from the air looks pock-marked, and there are no surface streams because all drainage occurs sub-surface. Examples of karst landscapes dotted with numerous enormous sinkholes are Khammouan Mountains (Laos) and Mamo Plateau (Papua New Guinea).^[5] The largest known sinkholes formed in sandstone are Sima Humboldt and Sima Martel in Venezuela.^[5]

The most impressive sinkholes form in thick layers of homogenous limestone. Their formation is facilitated by high groundwater flow, often caused by high rainfall; such rainfall causes formation of the giant sinkholes in Nakanaï Mountains, New Britain island in Papua New Guinea.^[6] On the contact of limestone and insoluble rock below it, powerful underground rivers may form, creating large underground voids.

In such conditions the largest known sinkholes of the world have formed, like the 662-metre (2,172 ft) deep Xiaozhai tiankeng (Chongqing, China), giant sótanos in Querétaro and San Luis Potosí states in Mexico and others.^[5][7][8]

Unusual processes have formed the enormous sinkholes of Sistema Zacatón in Tamaulipas (Mexico), where more than 20 sinkholes and other karst formations have been shaped by volcanically heated, acidic groundwater.^[9][10] This has secured not only the formation of the deepest water-filled sinkhole in the world — Zacatón — but also unique processes of travertine sedimentation in upper parts of sinkholes, leading to sealing of these sinkholes with travertine lids.^[10]

The state of Florida in the United States is known for having frequent sinkhole collapses, especially in the central part of the state. The Murge area in southern Italy also has numerous sinkholes. Sinkholes can be formed in retention ponds from large amounts of rain.^{[citation needed]}

The Great Blue Hole near Ambergris Caye, Belize.

Sinkholes have been used for centuries as disposal sites for various forms of waste. A consequence of this is the pollution of groundwater resources, with serious health implications in such areas. The Maya civilization sometimes used sinkholes in the Yucatán Peninsula (known as cenotes) as places to deposit precious items and human sacrifices.^{[citation needed]}

When sinkholes are very deep or connected to caves, they may offer challenges for experienced cavers or, when water-filled, divers. Some of the most spectacular are the Zacatón cenote in Mexico (the world’s deepest water-filled sinkhole), the Boesmansgat sinkhole in South Africa, Sarisariñama tepuy in Venezuela, and in the town of Mount Gambier, South Australia. Sinkholes that form in coral reefs and islands that collapse to enormous depths are known as blue holes, and often become popular diving spots.^{[citation needed]}

Image of the entire surface water flow of the Alapaha River near Jennings, Florida going into a sinkhole leading to the Floridan Aquifer groundwater.

The overburden sediments that cover buried cavities in the aquifer systems are delicately balanced by groundwater fluid pressure. The water below ground is actually helping to keep the surface soil in place. Groundwater pumping for urban water supply and for irrigation can produce new sinkholes in sinkhole-prone areas. If pumping results in a lowering of groundwater levels, then underground structural failure, and thus sinkholes, can occur.^{[citation needed]}

Local names of sinkholes

Large and visually unusual sinkholes have been well known to local people since ancient times. Nowadays sinkholes are grouped and named in site-specific or generic names. Some examples of such names are listed below.^[11]

• Cenotes – This refers to the characteristic water-filled sinkholes in the Yucatán Peninsula, Belize and some other regions. Many cenotes have formed in limestone deposited in shallow seas created by the Chicxulub meteorite’s impact.
• Tiankengs – These are extremely large sinkholes which are deeper and wider than 100 m, with mostly vertical walls, most often created by the collapse of underground caverns. This term is proposed by Chinese geologists as many of the largest sinkholes are located in China. The largest tiankeng is the 662 m deep Xiaozhai tiankeng, which is also the largest known sinkhole of the world.
• Sótanos – This name is given to several giant pits in several states of Mexico. The best known is the 372 m deep Sótano de las Golondrinas – Cave of Swallows.
• Blue holes – This name was initially given to the deep underwater sinkholes of the Bahamas but is often used for any deep water-filled pits formed in carbonate rocks. The name originates from the deep blue color of water in these sinkholes, which in turn is created by the high lucidity of water and the large depth of sinkholes – only the deep blue color of the visible spectrum can penetrate such depth and return back after reflection. The deepest known undersea sinkhole is Dean’s Blue Hole in the Bahamas.
• Black holes – This term refers to a group of unique, round, water-filled pits in the Bahamas. These formations seem to be dissolved in carbonate mud from above, by the sea water. The dark color of the water is caused by a layer of phototropic microorganisms concentrated in dense, purple colored layer in 15 – 20 metres depth – this layer “swallows” the light. Metabolism in the layer of microorganisms causes heating of the water – the only known case in the natural world where microorganisms create significant thermal effects. Most impressive is the Black Hole of Andros.^[12]
• Tomo – This term is used in New Zealand karst country to describe pot holes.

Piping pseudokarst

What has been called a “sinkhole” by the popular press formed suddenly in Guatemala in May 2010. Torrential rains from Tropical Storm Agatha and a bad drainage system were blamed for creating the 2010 “sinkhole” that swallowed a three story building and a house.^[13] This large vertical hole measured approximately 66 feet (20 m) wide and 100 feet (30 m) deep. A similar hole had formed nearby in February 2007.^[14][15]

This large vertical hole, called a “sinkhole” in the popular press, is not a true sinkhole as it did not form via the dissolution of limestone, dolomite, marble, or any other carbonate rock.^[16][17] Guatemala City is not underlain by any carbonate rock; instead, thick deposits of volcanic ash, unwelded ash flow tuffs, and other pyroclastic debris underlie all of Guatemala City. Thus, it is impossible for the dissolution of carbonate rock to have formed the large vertical holes that swallowed up parts of Guatemala City in 2007 and 2010.^[16]

The large holes that swallowed up parts of Guatemala City in 2007 and 2010 are a spectacular example of “piping pseudokarst”, created by the collapse of large cavities that had developed in the weak, crumbly Quaternary volcanic deposits underlying the city. Although weak and crumbly, these volcanic deposits have enough cohesion to allow them to stand in vertical faces and develop large subterranean voids within them. A process called “soil piping” first created large underground voids as water from leaking water mains flowed through these volcanic deposits and washed fine volcanic materials out of them, then progressively eroded and removed coarser materials. Eventually, these underground voids became large enough that their roofs collapsed to create large holes.^[16]

Notable sinkholes

Some of the largest and most impressive sinkholes in the world are:^[5]

• Xiaozhai tiankeng – Chongqing Municipality, China. Double nested sinkhole with vertical walls, 662 m deep.
• Dashiwei tiankeng – Guangxi, China. 613 m deep, with vertical walls, bottom contains an isolated patch of forest with rare species.
• Red Lake – Croatia. Approximately 530 m deep pit with nearly vertical walls, contains approximately 280 – 290 m deep lake.
• Minyé sinkhole – East New Britain, Papua New Guinea. 510 m deep, with vertical walls, crossed by a powerful stream.
• Sótano del Barro – Querétaro, Mexico. 410 m deep, with nearly vertical walls.
• Cave of Swallows – San Luis Potosí, Mexico. 372 m deep, round sinkhole with overhanging walls.
• Sima de las Cotorras – Chiapas, Mexico. 160 m across, 140 m deep, with thousands of green parakeets and ancient rock paintings.
• Zacatón – Tamaulipas, Mexico. Deepest water-filled sinkhole in world, 339 m deep. Floating travertine islands.
• Sima Humboldt – Venezuela. Largest sinkhole in sandstone, 314 m deep, with vertical walls. Unique, isolated forest on bottom.
• Teiq sinkhole – Oman. One of the largest sinkholes in the world by volume – 90 million cubic metres. Several perennial wadis fall with spectacular waterfalls into this 250 m deep sinkhole.
• Dean’s Blue Hole – Bahamas. Deepest known sinkhole under the sea, depth 203 m. Popular location for world championships of free diving.
• Blue Hole – Dahab, Egypt. A round sinkhole or blue hole, 130 m deep. Includes an extraordinary archway leading out to the Red Sea at 60 m, renowned for freediving and scuba attempts, the latter often fatal. Also see Bell’s to Blue Hole drift dive.
• Great Blue Hole – Belize. Spectacular, round sinkhole, 124 m deep. Unusual features are tilted stalactites in great depth, which mark the former orientation of limestone layers when this sinkhole was above sea level.
• Kingsley Lake – Florida, USA. 2,000 acres (8.1 km²) in area, 90 ft (27 m) deep and almost perfectly round.
• Gypsum Sinkhole – Utah, USA. Nearly 50 ft (15 m) in diameter and approximately 200 ft (61 m) deep^{[citation needed]}
• Harwood Hole – Abel Tasman National Park, New Zealand, 183 m deep
• Bahmah Sinkhole (Bimmah sinkhole) – Wadi Shab and Wadi Tiwi, Oman, approximately 30 m deep^[18]
• Boesmansgat – South African freshwater sinkhole, 280 m deep^{[citation needed]}
• Lake Kashiba – Zambia. About 3.5 hectares (8.6 acres) in area and about 100 metres (330 ft) deep

See also

• Blue hole
• Blyvooruitzicht
• Cave-in
• Cennet and Cehennem
• Cenote
• Estavelle
• Foiba
• Forau de Aigualluts
• Guatemala City Agatha Hole
• Karst topography
• Lake-burst
• Lake Peigneur disaster
• Oak Island
• Pipe Creek Sinkhole
• Ponor
• Sarisariñama
• Sinkhole Dersios
• Subsidence
• Turlough (lake)
• Voçoroca
• Sima Martel

References

1. ^ Lard, L., Paull, C., & Hobson, B. (1995). “Genesis of a submarine sinkhole without subaerial exposure”. Geology 23 (10): 949–951. Bibcode 1995Geo….23..949L. doi:10.1130/0091-7613(1995)023<0949:GOASSW>2.3.CO;2.
2. ^ “Caves and karst – dolines and sinkholes”. British Geological Survey. http://www.bgs.ac.uk/mendips/caveskarst/karst_3.htm.
3. ^ Martin S. Kohl Subsidence and sinkholes in East Tennessee. A field guide to holes in the ground (2001). (PDF) . Retrieved on 2011-04-24.
4. ^ Friend, Sandra (2002). Sinkholes. Pineapple Press Inc. p. 11. ISBN 1-56164-258-4. http://books.google.com/?id=Z5SWpk-38eYC&dq=sinkhole. Retrieved 2010-06-07.
5. ^ ^{a b c d} “Largest and most impressive sinkholes of the world”. Wondermondo. http://www.wondermondo.com/Best/World/Sinkholes.htm.
6. ^ “Naré sinkhole”. Wondermondo. http://www.wondermondo.com/Countries/Au/Papua/EastNewBritain/Nare.htm.
7. ^ “Tiankengs in the karst of China”. http://www.speleogenesis.info. http://www.speleogenesis.info/pdf/SG9/SG9_artId3290.pdf.
8. ^ “Sotano de las Guasguas”. Promo Tur un encuentro con Querétaro. http://www.promoturqueretaro.com.mx/detalles-de-noticias.php?id=105.
9. ^ “Sistema Zacatón”. by Marcus Gary. http://www.geo.utexas.edu/faculty/jmsharp/zacaton/default.htm.
10. ^ ^{a b} “Sistema Zacatón”. Wondermondo. http://www.wondermondo.com/Countries/NA/Mexico/Tamaulipas/SistemaZacaton.htm.
11. ^ “Sinkholes”. Wondermondo. http://www.wondermondo.com/Attractions/Sinkholes.htm.
12. ^ “Black Hole of Andros”. Wondermondo. http://www.wondermondo.com/Countries/NA/Bahamas/SouthAndros/AndrosBlackHole.htm.
13. ^ Dan Fletcher, Time.com (June 1, 2010). “Massive Sinkhole Opens in Guatemala City”. http://newsfeed.time.com/2010/06/01/giant-sinkhole-opens-in-guatemala-city/. Retrieved June 01 2010.
14. ^ Que diablos provoco este escalofriante hoy?. http://www.lun.com (2010-06-02). Retrieved on 2011-04-24.
15. ^ “Se abre hoyo de 100 metros en Guatemala”, Associated Press, February 23, 2007
16. ^ ^{a b c} Waltham, T. (2008). “Sinkhole hazard case histories in karst terrains”. Quarterly Journal of Engineering Geology and Hydrogeology 41 (3): 291–300. doi:10.1144/1470-9236/07-211.
17. ^ Halliday, W. R., 2007, Pseudokarst in the 21st century. Journal of Cave and Karst Studies. vol. 69, no. 1, pp. 103–113.
18. ^ “Bimmah sinkhole”. Wondermondo. http://www.wondermondo.com/Countries/As/Oman/Muscat/Bimmah.htm.

External links

Wikimedia Commons has media related to: Sinkholes

Wikisource has the text of the 1911 Encyclopædia Britannica article Swallow-hole.

• Daily Telegraph slide show of 31 sinkholes
• Florida Sinkhole Guide
• Kapsia Cave: Exploration of a Sinkhole in Arkadia, Greece
• Three people died and a dozen homes were swallowed up Friday by this sinkhole in Guatemala City. ( February 24, 2007)
• Video of Sinkhole forming in Texas (May 8, 2008)
• Spectacular sinkhole appeared in Guatemala City, Guatemala (May 31, 2010)
• Google map of deepest “hole” for each state (Andy Martin)
• Tennessee sinkholes
• Largest and most impressive sinkholes of the world by Wondermondo
• Sinkholes by Wondermondo

Blowout (well drilling)

From Wikipedia, the free encyclopedia

http://en.wikipedia.org/wiki/Blowout_%28well_drilling%29

A blowout is the uncontrolled release of crude oil and/or natural gas from an oil well or gas well after pressure control systems have failed.^[1]

Contents 1 History 1.1 Notable gushers 2 Cause of blowouts 2.1 Reservoir pressure 2.2 Formation kick 2.3 Well control 3 Types of blowouts 3.1 Surface blowouts 3.2 Subsea blowouts 3.3 Underground blowouts 4 Blowout control expertise 5 Methods of quenching blowouts 5.1 Use of nuclear explosions 6 Notable offshore well blowouts 7 See also 8 References 9 External links

History

Gushers were an icon of oil exploration during the late 19th and early 20th centuries. During that era, the simple drilling techniques such as cable-tool drilling and the lack of blowout preventers meant that drillers could not control high-pressure reservoirs. When these high pressure zones were breached the hydrocarbon fluids would travel up the well at a high rate, forcing out the drill string and creating a gusher. A well which began as a gusher was said to have “blown in”: for instance, the Lakeview Gusher blew in in 1910. These uncapped wells could produce large amounts of oil, often shooting 200 feet (60 m) or higher into the air.^[2] A blowout primarily composed of natural gas was known as a gas gusher.

Despite being symbols of new-found wealth, gushers were dangerous and wasteful. They killed workmen involved in drilling, destroyed equipment, and coated the landscape with thousands of barrels of oil; additionally, the explosive concussion released by the well when it pierces an oil/gas reservoir has been responsible for a number of oilmen losing their hearing entirely; standing too near to the drilling rig at the moment it drills into the oil reservoir is extremely hazardous. The impact on wildlife is very hard to quantify, but can only be estimated to be mild in the most optimistic models—realistically, the ecological impact is estimated by scientists across the ideological spectrum to be severe, profound, and lasting.^[3]

To complicate matters further, the free flowing oil was—and is—in danger of igniting.^[4] One dramatic account of a blowout and fire reads,

“With a roar like a hundred express trains racing across the countryside, the well blew out, spewing oil in all directions. The derrick simply evaporated. Casings wilted like lettuce out of water, as heavy machinery writhed and twisted into grotesque shapes in the blazing inferno.”^[5]

The development of rotary drilling techniques where the density of the drilling fluid is sufficient to overcome the downhole pressure of a newly penetrated zone meant that gushers became avoidable. If however the fluid density was not adequate or fluids were lost to the formation, then there was still a significant risk of a well blowout.

Plate tectonics 101 for the layman (includes females in its traditional usage) / laywoman (for ultra feminists who do not want to be listed under the term layman)

Recently, I saw on FB, Shak Lim Ho’s fantastic photos of China’s beautiful sights. One is that of an enormous sedimentary rock, maybe about 60 ft high, which protrude slanting out of the ground in district of Shennongjia, Province of Hubie, China. It is very beautiful and spectacular so I could not help but make a comment which included the geological basis for such an outcrop of rock and mentioned about the massive earthquakes that might have happened there in the distant past to have the original horizontal rock that size break and tilt that much.

To my surprise, one of Shak’s friends commented on my comment and mentioned about the San Fransisco earthquakes and asked about the small earthquakes there.

I am not a geologist, so I admitted it and left the question unanswered at first.

However, I as have been working and living together with geologists_ both petroleum and mineral_for nearly 20 years and have learned from them some basic geological facts and I have also read about some geological articles including the plate tectonics. So I know a little of the basics of the cause of earthquakes and volcanoes which can be explained by plate tectonics and I cannot just leave the question unanswered.

So I tried to explain about it as much as I can, without the heavy geological jargon which a geologist would use. I thought that as a layman (non geologist) I can explain as clearly to another to the extent I understand because difficult geological theories will not be included in my explaination (I still do not understand even the basics of Einstein’s theories however much it is explained because all the articles I read explain in terms beyond my comprehension).

This led me to write a note in FB to explain in more detail, the topic of plate tectonics for non-geologists, and when I began to post it in my blogsite and looking for diagrams to post to explain the theories involved, I came across newer facts I had not known earlier and this led me to revise my original note in FB.

The heading of this blog was “Plate tectonics 101” at first, but I changed it to “Plate tectonics 101 for the layman” as I do not want geologists to dwell on it. Later, I realized that some feminists consider many aspects of living in the male dominated world unappealing and might object to it. So I have changed it again, after several tries, to the final “Plate tectonics 101 for the layman (includes females in its traditional usage) / laywoman (for ultra feminists who do not want to be listed under the term layman)”. I hope they will be satisfied, and myself too after posting it as I cannot change it again then. I even have doubts now whether the original “Plate tectonics 101” might have been better.

I also hope that geologists will forgive me for writing about a topic which I am not properly trained, and will comment and point out any mistakes that might be included in it so that it will be of benefit for others and myself, and yet, anyway, ……, to continue ……or begin the explaination,…..(my prelude has been too much I am afraid) …..

Although the world seems to be solid, continuous and stationaly, it is actually moving relative to one another. The whole earth mass once was in continuity and it is called Pangaea which existed about 250 million years ago

The world is made up of large plates of solidified larva that sort of float on the still fluid magma deep inside the earth and move relative to the adjacent ones. At the edge of the adjacent plates which move horizontally in opposite directions, different directional forces move the adjacent plates but as they are locked in contact and cannot move freely, great tension developed at their contact edges which, when it exceeds the resistance that is holding the adjacent margins of the plates together, slip a little and then lock up again at another point until the pressure builds up to cause it to slip again. Earthquakes occur when the slip happens and when the resistance that hold the 2 plates is great, large tension will be required before it slips and if it do, the slip will be greater and the magnitude of the earthquake will be so too.

The Pacific ring of fire, the eastern margin which includes the west coast of the USA is an example. That is also why Indonesia has frequent earthquakes and tsunamis, and also many volcanoes which result from seepage of magma at the edge weak point there and also on the west coast of S. America.

You will find the following sites interesting:
http://www.cotf.edu/ete/modules/msese/earthsysflr/plates1.html
http://csep10.phys.utk.edu/astr161/lect/earth/tectonics.html

The famous San Andreas Fault on the West Coast of the USA is an example of the edge between 2 tectonic plates
http://en.wikipedia.org/wiki/San_Andreas_Fault

Sometimes the plates diverge rather than slip past each other and that is why the Americas and the Europe-Africa coasts which once was in continuity, is now separated by the Atlantic ocean, in whose bed in the middle is the “mid Atlantic ridge” …which is the boundary between the North American plate and the Eurasion plate which are moving away from each other and where new sea bed continuously form. see:
http://www.platetectonics.com/oceanfloors/africa.asp
http://www.wisegeek.com/what-is-the-mid-atlantic-ridge.htm

Sometimes the plates meet head on and converge on each other and one plate might go under the other:
subduction of the Nazca Plate beneath the South American Plate to form the Andes.
subduction of the northern part of the Pacific Plate and the NW North American Plate that is forming the Aleutian Islands.

Sometimes both the plates press on each other and at the point where they meet, the earth is piled up:

Collision between the Eurasian Plate and the Indian Plate that is forming the Himalayas.
Collision of the Eurasian Plate and the African Plate formed the Pontic Mountains in Turkey.

also see:
http://library.thinkquest.org/17701/high/tectonics/ptconv.html
http://en.wikipedia.org/wiki/Convergent_boundary

http://www.extremescience.com/zoom/index.php/plate-tectonics-lesson

Those who are interested can read more below, which are actually only parts of the original articles I have reproduced from the resources available to me, which I find interesting and have emphasized with bold and underscore, the important facts in the interesting topic. To read more, please go to the original sites mentioned.

Pangaea

From Wikipedia, the free encyclopedia

http://en.wikipedia.org/wiki/Pangaea

Jump to: navigation, search

For other uses, see Pangaea (disambiguation).

Pangaea, Pangæa, or Pangea (pronounced /pænˈdʒiːə/, pan-JEE-ə^[1], from Ancient Greek πᾶν pan “entire”, and Γαῖα Gaia “Earth”, Latinized as Gæa) was the supercontinent that existed during the Paleozoic and Mesozoic eras about 250 million years ago, before the component continents were separated into their current configuration.^[2]

The name was coined in the scientific discussion of Alfred Wegener‘s theory of the Continental drift. In his book “The Origin of Continents and Oceans” (Die Entstehung der Kontinente und Ozeane) he postulated that all the continents had at one time formed a single supercontinent which he called the “Urkontinent”, before later breaking up and drifting to their present locations. The term Pangaea appeared in 1928 during a symposium to discuss Alfred Wegener’s theory.^[3]

The single enormous ocean which surrounded Pangaea was accordingly named Panthalassa.

Formation

The breaking up and formation of supercontinents appears to be cyclical through Earth’s 4.6 billion year history. There may have been several others before Pangaea. The next-to-last one, Pannotia, formed about 600 million years ago (Ma) during the Proterozoic eon, and lasted until 540 Ma. Before Pannotia, there was Rodinia, which lasted from about 1.1 billion years ago (Ga) until about 750 million years ago. Rodinia formed by the accretion and assembly of fragments produced by breakup of an older supercontinent, called Columbia or Nuna that was assembled in the period 2.0-1.8 Ga ^[4][5]. The exact configuration and geodynamic history of Rodinia are not nearly as well understood as Pannotia and Pangaea. When Rodinia broke up, it split into three pieces: the supercontinent of Proto-Laurasia and the supercontinent of Proto-Gondwana, and the smaller Congo craton. Proto-Laurasia and Proto-Gondwanaland were separated by the Proto-Tethys Ocean. Soon thereafter Proto-Laurasia itself split apart to form the continents of Laurentia, Siberia and Baltica. The rifting also spawned two new oceans, the Iapetus Ocean and Paleoasian Ocean. Baltica was situated east of Laurentia, and Siberia northeast of Laurentia.

Around 600 Ma, most of these masses came back together to form the relatively short-lived supercontinent of Pannotia, which included large amounts of land near the poles and only a relatively small strip near the equator connecting the polar masses.

Only 60 million years after its formation, about 540 Ma, near the beginning of the Cambrian epoch, Pannotia in turn broke up, giving rise to the continents of Laurentia, Baltica, and the southern supercontinent of Gondwana.

In the Cambrian period the independent continent of Laurentia, which would become North America, sat on the equator, with three bordering oceans: the Panthalassic Ocean to the north and west, the Iapetus Ocean to the south and the Khanty Ocean to the east. In the Earliest Ordovician, around 480 Ma, the microcontinent of Avalonia, a landmass that would become the northeastern United States, Nova Scotia and England, broke free from Gondwana and began its journey to Laurentia.^[6]

Baltica, Laurentia, and Avalonia all came together by the end of the Ordovician to form a minor supercontinent called Euramerica or Laurussia, closing the Iapetus Ocean. The collision also resulted in the formation of the northern Appalachians. Siberia sat near Euramerica, with the Khanty Ocean between the two continents. While all this was happening, Gondwana drifted slowly towards the South Pole. This was the first step of the formation of Pangaea.^[7]

The second step in the formation of Pangaea was the collision of Gondwana with Euramerica. By Silurian time, 440 Ma, Baltica had already collided with Laurentia to form Euramerica. Avalonia had not collided with Laurentia yet, and a seaway between them, a remnant of the Iapetus Ocean, was still shrinking as Avalonia slowly inched towards Laurentia.

Meanwhile, southern Europe fragmented from Gondwana and started to head towards Euramerica across the newly formed Rheic Ocean and collided with southern Baltica in the Devonian, though this microcontinent was an underwater plate. The Iapetus Ocean’s sister ocean, the Khanty Ocean, was also shrinking as an island arc from Siberia collided with eastern Baltica (now part of Euramerica). Behind this island arc was a new ocean, the Ural Ocean.

By late Silurian time, North and South China rifted away from Gondwana and started to head northward across the shrinking Proto-Tethys Ocean, and on its southern end the new Paleo-Tethys Ocean was opening. In the Devonian Period, Gondwana itself headed towards Euramerica, which caused the Rheic Ocean to shrink.

In the Early Carboniferous, northwest Africa had touched the southeastern coast of Euramerica, creating the southern portion of the Appalachian Mountains, and the Meseta Mountains. South America moved northward to southern Euramerica, while the eastern portion of Gondwana (India, Antarctica and Australia) headed towards the South Pole from the equator.

North China and South China were on independent continents. The Kazakhstania microcontinent had collided with Siberia (Siberia had been a separate continent for millions of years since the deformation of the supercontinent Pannotia) in the Middle Carboniferous.

Western Kazakhstania collided with Baltica in the Late Carboniferous, closing the Ural Ocean between them, and the western Proto-Tethys in them (Uralian orogeny), causing the formation of the Ural Mountains, and the formation of the supercontinent of Laurasia. This was the last step of the formation of Pangaea.

Meanwhile, South America had collided with southern Laurentia, closing the Rheic Ocean, and forming the southernmost part of the Appalachians and Ouachita Mountains. By this time, Gondwana was positioned near the South Pole, and glaciers were forming in Antarctica, India, Australia, southern Africa and South America. The North China block collided with Siberia by Late Carboniferous time, completely closing the Proto-Tethys Ocean.

By Early Permian time, the Cimmerian plate rifted away from Gondwana and headed towards Laurasia, with a new ocean forming in its southern end, the Tethys Ocean, and the closure of the Paleo-Tethys Ocean. Most of the landmasses were all in one. By the Triassic Period, Pangaea rotated a little, in a southwest direction. The Cimmerian plate was still travelling across the shrinking Paleo-Tethys, until the Middle Jurassic time. The Paleo-Tethys had closed from west to east, creating the Cimmerian Orogeny. Pangaea looked like a C, with an ocean inside the C, the new Tethys Ocean. Pangaea had rifted by the Middle Jurassic, and its deformation is explained below.

Evidence of existence

Fossil evidence for Pangaea includes the presence of similar and identical species on continents that are now great distances apart. For example, fossils of the therapsid Lystrosaurus have been found in South Africa, India and Australia, alongside members of the Glossopteris flora, whose distribution would have ranged from the polar circle to the equator if the continents had been in their present position; similarly, the freshwater reptile Mesosaurus has only been found in localized regions of the coasts of Brazil and West Africa.^[8]

Additional evidence for Pangaea is found in the geology of adjacent continents, including matching geological trends between the eastern coast of South America and the western coast of Africa.

The polar ice cap of the Carboniferous Period covered the southern end of Pangaea. Glacial deposits, specifically till, of the same age and structure are found on many separate continents which would have been together in the continent of Pangaea.^[9]

Paleomagnetic study of apparent polar wandering paths also support the theory of a super-continent. Geologists can determine the movement of continental plates by examining the orientation of magnetic minerals in rocks; when rocks are formed, they take on the magnetic properties of the Earth and indicate in which direction the poles lie relative to the rock. Since the magnetic poles drift about the rotational pole with a period of only a few thousand years, measurements from numerous lavas spanning several thousand years are averaged to give an apparent mean polar position. Samples of sedimentary rock and intrusive igneous rock have magnetic orientations that typically are an average of these “secular variations” in the orientation of Magnetic North because their magnetic fields are not formed in an instant, as is the case in a cooling lava. Magnetic differences between sample groups whose age varies by millions of years is due to a combination of true polar wander and the drifting of continents. The true polar wander component is identical for all samples, and can be removed. This leaves geologists with the portion of this motion that shows continental drift, and can be used to help reconstruct earlier continental positions.^[10]

The continuity of mountain chains also provide evidence for Pangea. One example of this is the Appalachian Mountains chain which extends from the northeastern United States to the Caledonides of Ireland, Britain, Greenland, and Scandinavia.^[11]

Rifting and break-up

There were three major phases in the break-up of Pangaea. The first phase began in the Early–Middle Jurassic (about 175 Ma), when Pangaea began to rift from the Tethys Ocean in the east and the Pacific in the west, ultimately giving rise to the supercontinents Laurasia and Gondwana. The rifting that took place between North America and Africa produced multiple failed rifts. One rift resulted in a new ocean, the North Atlantic Ocean^[12].

The Atlantic Ocean did not open uniformly; rifting began in the north-central Atlantic. The South Atlantic did not open until the Cretaceous. Laurasia started to rotate clockwise and moved northward with North America to the north, and Eurasia to the south. The clockwise motion of Laurasia also led to the closing of the Tethys Ocean. Meanwhile, on the other side of Africa, new rifts were also forming along the adjacent margins of east Africa, Antarctica and Madagascar that would lead to the formation of the southwestern Indian Ocean that would also open up in the Cretaceous.

The second major phase in the break-up of Pangaea began in the Early Cretaceous (150–140 Ma), when the minor supercontinent of Gondwana separated into multiple continents (Africa, South America, India, Antarctica, and Australia). About 200 Ma, the continent of Cimmeria, as mentioned above (see “Formation of Pangaea“), collided with Eurasia. However, a subduction zone was forming, as soon as Cimmeria collided.^[12]

This subduction zone was called the Tethyan Trench. This trench might have subducted what is called the Tethyan mid-ocean ridge, a ridge responsible for the Tethys Ocean’s expansion. It probably caused Africa, India and Australia to move northward. In the Early Cretaceous, Atlantica, today’s South America and Africa, finally separated from eastern Gondwana (Antarctica, India and Australia), causing the opening of a “South Indian Ocean”. In the Middle Cretaceous, Gondwana fragmented to open up the South Atlantic Ocean as South America started to move westward away from Africa. The South Atlantic did not develop uniformly; rather, it rifted from south to north.

Also, at the same time, Madagascar and India began to separate from Antarctica and moved northward, opening up the Indian Ocean. Madagascar and India separated from each other 100–90 Ma in the Late Cretaceous. India continued to move northward toward Eurasia at 15 centimeters (6 in) per year (a plate tectonic record), closing the Tethys Ocean, while Madagascar stopped and became locked to the African Plate. New Zealand, New Caledonia and the rest of Zealandia began to separate from Australia, moving eastward towards the Pacific and opening the Coral Sea and Tasman Sea.

The third major and final phase of the break-up of Pangaea occurred in the early Cenozoic (Paleocene to Oligocene). Laurasia split when North America/Greenland (also called Laurentia) broke free from Eurasia, opening the Norwegian Sea about 60–55 Ma. The Atlantic and Indian Oceans continued to expand, closing the Tethys Ocean.

Meanwhile, Australia split from Antarctica and moved rapidly northward, just as India did more than 40 million years earlier, and is currently on a collision course with eastern Asia. Both Australia and India are currently moving in a northeastern direction at 5–6 centimeters (2–3 in) per year. Antarctica has been near or at the South Pole since the formation of Pangaea about 280 Ma. India started to collide with Asia beginning about 35 Ma, forming the Himalayan orogeny, and also finally closing the Tethys Seaway; this collision continues today. The African Plate started to change directions, from west to northwest toward Europe, and South America began to move in a northward direction, separating it from Antarctica and allowing complete oceanic circulation around Antarctica for the first time, causing a rapid cooling of the continent and allowing glaciers to form. Other major events took place during the Cenozoic, including the opening of the Gulf of California, the uplift of the Alps, and the opening of the Sea of Japan. The break-up of Pangaea continues today in the Great Rift Valley

Plate Tectonics – Pangaea Continent Maps

Plate tectonics is the study of the lithosphere, the outer portion of the earth consisting of the crust and part of the upper mantle. The lithosphere is divided into about a dozen large plates which move and interact with one another to create earthquakes, mountain ranges, volcanic activity, ocean trenches and many other features. Continents and ocean basis are moved and changed in shape as a result of these plate movements.

The sequence of maps below show how a large supercontinent, known as Pangaea was fragmented into several pieces, each being part of a mobile plate of the lithosphere. These pieces were to become Earth’s current continents. The time sequence show through the maps traces the paths of the continents to their current positions..

In the early 1900′s Alfred Wegener proposed the idea of Continental Drift. His ideas centered around continents moving across the face of the earth. The idea was not quite correct – compared to the plate tectonics theory of today – but his thinking was on the proper track. In addition, a variant spelling of Pangaea is “Pangea“. It appears in some textbooks and glossaries, however, Pangaea is the current preferred spelling.

http://www.cotf.edu/ete/modules/msese/earthsysflr/plates1.html

The theory of plate tectonics has done for geology what Charles Darwin’s theory of evolution did for biology. It provides geology with a comprehensive theory that explains “how the Earth works.” The theory was formulated in the 1960s and 1970s as new information was obtained about the nature of the ocean floor, Earth’s ancient magnetism, the distribution of volcanoes and earthquakes, the flow of heat from Earth’s interior, and the worldwide distribution of plant and animal fossils.

The theory states that Earth’s outermost layer, the lithosphere, is broken into 7 large, rigid pieces called plates: the African, North American, South American, Eurasian, Australian, Antarctic, and Pacific plates. Several minor plates also exist, including the Arabian, Nazca, and Philippines plates.

The plates are all moving in different directions and at different speeds (from 2 cm to 10 cm per year–about the speed at which your fingernails grow) in relationship to each other. The plates are moving around like cars in a demolition derby, which means they sometimes crash together, pull apart, or sideswipe each other. The place where the two plates meet is called a plate boundary. Boundaries have different names depending on how the two plates are moving in relationship to each other

Convergent Boundaries
http://www.cotf.edu/ete/modules/msese/earthsysflr/plates2.html

Places where plates crash or crunch together are called convergent boundaries. Plates only move a few centimeters each year, so collisions are very slow and last millions of years. Even though plate collisions take a long time, lots of interesting things happen. For example, in the drawing above, an oceanic plate has crashed into a continental plate. Looking at this drawing of two plates colliding is like looking at a single frame in a slow-motion movie of two cars crashing into each other. Just as the front ends of cars fold and bend in a collision, so do the “front ends” of colliding plates. The edge of the continental plate in the drawing has folded into a huge mountain range, while the edge of the oceanic plate has bent downward and dug deep into the Earth. A trench has formed at the bend. All that folding and bending makes rock in both plates break and slip, causing earthquakes. As the edge of the oceanic plate digs into Earth’s hot interior, some of the rock in it melts. The melted rock rises up through the continental plate, causing more earthquakes on its way up, and forming volcanic eruptions where it finally reaches the surface. An example of this type of collision is found on the west coast of South America where the oceanic Nazca Plate is crashing into the continent of South America. The crash formed the Andes Mountains, the long string of volcanoes along the mountain crest, and the deep trench off the coast in the Pacific Ocean.

Are They Dangerous Places to Live?
Mountains, earthquakes, and volcanoes form where plates collide. Millions of people live in and visit the beautiful mountain ranges being built by plate collisions. For example, the Rockies in North America, the Alps in Europe, the Pontic Mountains in Turkey, the Zagros Mountains in Iran, and the Himalayas in central Asia were formed by plate collisions. Each year, thousands of people are killed by earthquakes and volcanic eruptions in those mountains. Occasionally, big eruptions or earthquakes kill large numbers of people. In 1883 an eruption of Krakatau volcano in Indonesia killed 37,000 people. In 1983 an eruption-caused mudslide on Nevada del Ruiz in Columbia killed 25,000 people. In 1976, an earthquake in Tangshan, China killed an astounding 750,000 people.

On the other hand, earthquakes and volcanoes occurring in areas where few people live harm no one. If we choose to live near convergent plate boundaries, we can build buildings that can resist earthquakes, and we can evacuate areas around volcanoes when they threaten to erupt. Yes, convergent boundaries are dangerous places to live, but with preparation and watchfulness, the danger can be lessened somewhat.

Divergent Boundaries
http://www.cotf.edu/ete/modules/msese/earthsysflr/plates3.html

Places where plates are coming apart are called divergent boundaries. As shown in the drawing above, when Earth’s brittle surface layer (the lithosphere) is pulled apart, it typically breaks along parallel faults that tilt slightly outward from each other. As the plates separate along the boundary, the block between the faults cracks and drops down into the soft, plastic interior (the asthenosphere). The sinking of the block forms a central valley called a rift. Magma (liquid rock) seeps upward to fill the cracks. In this way, new crust is formed along the boundary. Earthquakes occur along the faults, and volcanoes form where the magma reaches the surface.

Where a divergent boundary crosses the land, the rift valleys which form are typically 30 to 50 kilometers wide. Examples include the East Africa rift in Kenya and Ethiopia, and the Rio Grande rift in New Mexico. Where a divergent boundary crosses the ocean floor, the rift valley is much narrower, only a kilometer or less across, and it runs along the top of a midoceanic ridge. Oceanic ridges rise a kilometer or so above the ocean floor and form a global network tens of thousands of miles long. Examples include the Mid-Atlantic ridge and the East Pacific Rise.

Plate separation is a slow process. For example, divergence along the Mid Atlantic ridge causes the Atlantic Ocean to widen at only about 2 centimeters per year

Transform Boundaries
http://www.cotf.edu/ete/modules/msese/earthsysflr/plates4.html

Places where plates slide past each other are called transform boundaries. Since the plates on either side of a transform boundary are merely sliding past each other and not tearing or crunching each other, transform boundaries lack the spectacular features found at convergent and divergent boundaries. Instead, transform boundaries are marked in some places by linear valleys along the boundary where rock has been ground up by the sliding. In other places, transform boundaries are marked by features like stream beds that have been split in half and the two halves have moved in opposite directions.

Perhaps the most famous transform boundary in the world is the San Andreas fault, shown in the drawing above. The slice of California to the west of the fault is slowly moving north relative to the rest of California. Since motion along the fault is sideways and not vertical, Los Angeles will not crack off and fall into the ocean as popularly thought, but it will simply creep towards San Francisco at about 6 centimeters per year. In about ten million years, the two cities will be side by side!

Although transform boundaries are not marked by spectacular surface features, their sliding motion causes lots of earthquakes. The strongest and most famous earthquake along the San Andreas fault hit San Francisco in 1906. Many buildings were shaken to pieces by the quake, and much of the rest of the city was destroyed by the fires that followed. More than 600 people died as a result of the quake and fires. Recent large quakes along the San Andreas include the Imperial Valley quake in 1940 and the Loma Prieta quake in 1989

How Plate Tectonics Works

http://www.extremescience.com/zoom/index.php/plate-tectonics-lesson

Way back in 1912 a scientist by the name of Alfred Wegener came up with a crazy idea. He noticed that all of the continents seemed to fit together like the pieces of a giant puzzle. He thought, “Maybe they were once all joined together in a single, giant landmass that broke up and drifted apart over time?”. He decided to give this supercontinent a name and called it Pangea, meaning, “all lands”. At the time he presented his idea to the scientific community it came to be known as continental drift theory. Wegener was unable to find solid evidence to support his theory, so the other scientists laughed him off as a crackpot. One of his suggestions for the cause of continental drift was that centrifugal force from the rotation of the earth caused the continents to slide into each other and move around on the surface. They all calculated that there wasn’t enough force generated by the earth’s rotation to cause shifting of the crust and nobody took him seriously. They were all convinced the earth was rock-solid and immovable.

But then in 1929, along came a scientist named Arthur Holmes who didn’t think that Wegener’s theory of continental drift was too farfetched. “Now wait just a minute. Maybe he’s got something here”, he told them. He mentioned one of Wegener’s other theories about the source of continental drift; the idea that the molten mantle beneath the earth’s crust experiences thermal convection and that the movement of these convection currents in the mantle could cause an upwelling beneath the crust, forcing it to break apart and move. Now, that sounded like a semi-reasonable explanation for the movement of the earth’s crust. As a matter of fact, if you looked closely at this idea it explained a lot of things, not just the continental puzzle idea. It also explained how mountain ranges were formed – by continents crashing into each other and ‘rumpling up rock’. Still, the other scientists just nodded and said, ‘Yeah. Fine. Whatever’. And the theory was neatly tucked away and ignored.

Scientists are trained to be skeptical. They were all waiting for a preponderance of evidence that backed up this harebrained theory.

Over the next thirty years a lot of new and surprise discoveries were made as new technologies were developed for exploring the ocean floor . The discovery of volcanic activity on the ocean floor in the middle of the Antlantic that turned out to be part of a long, unbroken mountain chain of undersea volcanoes was the most ground-breaking discovery that supported the theory of continental drift. Scientists developed instruments for measuring earthquake activity around the world and began plotting the locations of earthquakes. They all got together and started drawing a new map of the world that showed volcanic and seismic (earthquake) activity was concentrated along certain areas that looked like the margins of huge crustal plates. During the 1960s several scientists published papers that reviewed the preponderance of evidence that had been gathered for the theory of continental drift and it soon came to be known as the theory of plate tectonics.

Plate tectonics

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The tectonic plates of the world were mapped in the second half of the 20th century.

Plate tectonics (from the Late Latin tectonicus, from the Greek: τεκτονικός “pertaining to building”) (Little, Fowler & Coulson 1990)^[1] is a scientific theory which describes the large scale motions of Earth‘s lithosphere. The theory builds on the older concepts of continental drift, developed during the first decades of the 20th century (one of the most famous advocates was Alfred Wegener), and was accepted by the majority of the Geoscientific community when the concepts of seafloor spreading were developed in the late 1950s and early 1960s. The lithosphere is broken up into what are called “tectonic plates”. In the case of the Earth, there are currently seven to eight major (depending on how they are defined) and many minor plates. The lithospheric plates ride on the asthenosphere. These plates move in relation to one another at one of three types of plate boundaries: convergent, or collisional boundaries; divergent boundaries, also called spreading centers; and conservative transform boundaries. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative movement of the plates varies, though it is typically 0–100 mm annually (Read & Watson 1975)^[2].

The tectonic plates are composed of two types of lithosphere: thicker continental and thin oceanic. The upper part is called the crust, again of two types (continental and oceanic). This means that a plate can be of one type, or of both types. One of the main points the theory proposes is that the amount of surface of the (continental and oceanic) plates that disappear in the mantle along the convergent boundaries by subduction is more or less in equilibrium with the new (oceanic) crust that is formed along the divergent margins by seafloor spreading. This is also referred to as the “conveyor belt” principle. In this way, the total surface of the Globe remains the same. This is in contrast with earlier theories advocated before the Plate Tectonics “paradigm“, as it is sometimes called, became the main scientific model, theories that proposed gradual shrinking (contraction) or gradual expansion of the Globe, and that still exist in science as alternative models.

Regarding the driving mechanism of the plates various models co-exist: Tectonic plates are able to move because the Earth’s lithosphere has a higher strength and lower density than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Their movement is thought to be driven by a combination of the motion of seafloor away from the spreading ridge (due to variations in topography and density of the crust that result in differences in gravitational forces) and drag, downward suction, at the subduction zones. A different explanation lies in different forces generated by the rotation of the Globe and tidal forces of the Sun and the Moon. The relative importance of each of these factors is unclear.

Key principles

The outer layers of the Earth are divided into lithosphere and asthenosphere. This is based on differences in mechanical properties and in the method for the transfer of heat. Mechanically, the lithosphere is cooler and more rigid, while the asthenosphere is hotter and flows more easily. In terms of heat transfer, the lithosphere loses heat by conduction whereas the asthenosphere also transfers heat by convection and has a nearly adiabatic temperature gradient. This division should not be confused with the chemical subdivision of these same layers into the mantle (comprising both the asthenosphere and the mantle portion of the lithosphere) and the crust: a given piece of mantle may be part of the lithosphere or the asthenosphere at different times, depending on its temperature and pressure.

The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, which ride on the fluid-like (visco-elastic solid) asthenosphere. Plate motions range up to a typical 10–40 mm/a (Mid-Atlantic Ridge; about as fast as fingernails grow), to about 160 mm/a (Nazca Plate; about as fast as hair grows) (Zhen Shao 1997^[3]; Hancock, Skinner & Dineley 2000^[4]). The driving mechanism behind this movement is described below in a separate section.

Tectonic lithosphere plates consist of lithospheric mantle overlain by either or both of two types of crustal material: oceanic crust (in older texts called sima from silicon and magnesium) and continental crust (sial from silicon and aluminium). Average oceanic lithosphere is typically 100 km thick (Turcotte & Schubert 2002)^[5]; its thickness is a function of its age: as time passes, it conductively cools and becomes thicker. Because it is formed at mid-ocean ridges and spreads outwards, its thickness is therefore a function of its distance from the mid-ocean ridge where it was formed. For a typical distance oceanic lithosphere must travel before being subducted, the thickness varies from about 6 km thick at mid-ocean ridges to greater than 100 km at subduction zones; for shorter or longer distances, the subduction zone (and therefore also the mean) thickness becomes smaller or larger, respectively (Turcotte & Schubert 2002)^[6]. Continental lithosphere is typically ~200 km thick, though this also varies considerably between basins, mountain ranges, and stable cratonic interiors of continents. The two types of crust also differ in thickness, with continental crust being considerably thicker than oceanic (35 km vs. 6 km) (Turcotte & Schubert 2002)^[7].

The location where two plates meet is called a plate boundary, and plate boundaries are commonly associated with geological events such as earthquakes and the creation of topographic features such as mountains, volcanoes, mid-ocean ridges, and oceanic trenches. The majority of the world’s active volcanoes occur along plate boundaries, with the Pacific Plate’s Ring of Fire being most active and most widely known. These boundaries are discussed in further detail below.

As explained above, tectonic plates can include continental crust or oceanic crust, and many plates contain both. For example, the African Plate includes the continent and parts of the floor of the Atlantic and Indian Oceans. The distinction between oceanic crust and continental crust is based on their modes of formation. Oceanic crust is formed at sea-floor spreading centers, and continental crust is formed through arc volcanism and accretion of terranes through tectonic processes; though some of these terranes may contain ophiolite sequences, which are pieces of oceanic crust, these are considered part of the continent when they exit the standard cycle of formation and spreading centers and subduction beneath continents. Oceanic crust is also denser than continental crust owing to their different compositions. Oceanic crust is denser because it has less silicon and more heavier elements (“mafic“) than continental crust (“felsic“) (Schmidt & Harbert 1998)^[8]. As a result of this density stratification, oceanic crust generally lies below sea level (for example most of the Pacific Plate), while the continental crust buoyantly projects above sea level (see the page isostasy for explanation of this principle).

Types of plate boundaries

Basically, three types of plate boundaries exist (Meissner 2002, p. 100), with a fourth, mixed type, characterized by the way the plates move relative to each other. They are associated with different types of surface phenomena. The different types of plate boundaries are:^[9][10]

1. Transform boundaries (Conservative) occur where plates slide or, perhaps more accurately, grind past each other along transform faults. The relative motion of the two plates is either sinistral (left side toward the observer) or dextral (right side toward the observer). The San Andreas Fault in California is an example of a transform boundary exhibiting dextral motion.
2. Divergent boundaries (Constructive) occur where two plates slide apart from each other. Mid-ocean ridges (e.g., Mid-Atlantic Ridge) and active zones of rifting (such as Africa’s Great Rift Valley) are both examples of divergent boundaries.
3. Convergent boundaries (Destructive) (or active margins) occur where two plates slide towards each other commonly forming either a subduction zone (if one plate moves underneath the other) or a continental collision (if the two plates contain continental crust). Deep marine trenches are typically associated with subduction zones. The subducting slab contains many hydrous minerals, which release their water on heating; this water then causes the mantle to melt, producing volcanism. Examples of this are the Andes mountain range in South America and the Japanese island arc.
4. Plate boundary zones occur where the effects of the interactions are unclear and the broad belt boundaries are not well defined.

slanting sedimentary rock, district of Shennongjia, Hubie province, China

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