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။
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.
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.
< Devadatta>
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.
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.
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>
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 swallowing up of both Devadatta and Cinca Manavika occurred near the Jetavana monastery in Sravasti သာ၀တၱိ of Kosala Kingdom.
Modern day Sravasti သာ၀တၱိ
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 |
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
References
- ^ 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
- ^ Discovery Channel. MythBusters. Season 2. “Killer Quicksand.” October 20, 2004.
- ^ 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.
- ^ 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
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.
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“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 |
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
- ^ 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.
- ^ “Caves and karst – dolines and sinkholes”. British Geological Survey. http://www.bgs.ac.uk/mendips/caveskarst/karst_3.htm.
- ^ Martin S. Kohl Subsidence and sinkholes in East Tennessee. A field guide to holes in the ground (2001). (PDF) . Retrieved on 2011-04-24.
- ^ 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.
- ^ a b c d “Largest and most impressive sinkholes of the world”. Wondermondo. http://www.wondermondo.com/Best/World/Sinkholes.htm.
- ^ “Naré sinkhole”. Wondermondo. http://www.wondermondo.com/Countries/Au/Papua/EastNewBritain/Nare.htm.
- ^ “Tiankengs in the karst of China”. http://www.speleogenesis.info. http://www.speleogenesis.info/pdf/SG9/SG9_artId3290.pdf.
- ^ “Sotano de las Guasguas”. Promo Tur un encuentro con Querétaro. http://www.promoturqueretaro.com.mx/detalles-de-noticias.php?id=105.
- ^ “Sistema Zacatón”. by Marcus Gary. http://www.geo.utexas.edu/faculty/jmsharp/zacaton/default.htm.
- ^ a b “Sistema Zacatón”. Wondermondo. http://www.wondermondo.com/Countries/NA/Mexico/Tamaulipas/SistemaZacaton.htm.
- ^ “Sinkholes”. Wondermondo. http://www.wondermondo.com/Attractions/Sinkholes.htm.
- ^ “Black Hole of Andros”. Wondermondo. http://www.wondermondo.com/Countries/NA/Bahamas/SouthAndros/AndrosBlackHole.htm.
- ^ 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.
- ^ Que diablos provoco este escalofriante hoy?. http://www.lun.com (2010-06-02). Retrieved on 2011-04-24.
- ^ “Se abre hoyo de 100 metros en Guatemala”, Associated Press, February 23, 2007
- ^ 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.
- ^ Halliday, W. R., 2007, Pseudokarst in the 21st century. Journal of Cave and Karst Studies. vol. 69, no. 1, pp. 103–113.
- ^ “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 |
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.