Earthquakes and Liquifaction

  • Thread starter Andre
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  • #1
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During heavy earthquackes sand can behave as liquid and lose the capacity to bear weight causing catastrophic destruction.

http://earthobservatory.nasa.gov/Study/Earthquake/

Survivors of the New Madrid [Missouri, 1811]earthquakes reported not only intense ground shaking and land movement, as would be expected during an earthquake, but also an unfamiliar phenomenon: water and sand spouting up through fissures, or cracks, in the Earth’s surface. In a letter published in Lorenzo Dow’s Journal, New Madrid resident Eliza Bryan wrote in 1816:

. . . the surface of hundreds of acres was, from time to time, covered over in various depths by the sand which issued from the fissures, which were made in great numbers all over this country, some of which closed up immediately after they had vomited forth their sand and water . . . "

"...the fluid comes shooting to the surface.” These fountains of water can sometimes shoot as high as 30 feet into the air, according to Tuttle."
But apparantly it can sink cities into the ground or water:

http://news.nationalgeographic.com/news/2001/10/1017_NileCities.html

Two cities that lay at the edge of the Mediterranean more than 1,200 years ago, Herakleion and Eastern Canopus, disappeared suddenly, swallowed by the sea. Now, an international team of scientists may have figured out the mystery of why it happened.

The researchers have concluded that the two cities collapsed when the land they were built on suddenly liquefied.
Could we think of more mysteries that could be solved by liquifaction?
 
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Answers and Replies

  • #2
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I was thinking of those two mammoth mummies, The Jarkov and the Fishhook:

The Jarkov Mammoth
... in Rotterdam (the Netherlands) Buigues and Mol (1999) announced the discovery of the Jarkov Mammoth in the permafrost of the Taimyr Peninsula, Arctic Siberia. The Jarkov Mammoth is a male woolly mammoth, Mammuthus primigenius, that died at an age of 47-49 AEY, on the Taimyr Peninsula, c. 20,380 BP. In September/October, 1999, introducing a new technique, the CERPOLEX / Mammuthus team excavated a huge block of frozen sediment that likely included the remains of the mammoth

.........

The geology of the block

The block containing the Jarkov Mammoth was geologically mapped and studied using field methods. It contains four sedimentary units, reflecting different genetic processes and geological origin. (1) The lowermost horizon (up to 140 cm thick) is a grayish brown silty clay. At a level below the actual block, it contained fossil plant remains that have been radiocarbon dated to c. 27,000 BP. In the eastern section of the block, a gravel interfingers with the clay. This lowermost sedimentary unit is of fluvio-limnic character. The plant remains indicate a relatively warm period prior to the Sartanian (late Weichselian, 18,000 - 12,500 BP). (2) The next youngest horizon (up to 35 cm thick) is a pale brown clayey silt, which occasionally exhibits horizontal bedding. The layer is an aeolian sediment indicating dry and cold climatic conditions, most likely of Sartanian age. (3) The third horizon (up to 25 cm thick) is a clearly laminated silty-fine sand. Cross-bedding is visible in the western section of the block. The sediment was transported and deposited by shallow water of moderate current strength. This unit seems to have been produced by reworking of windblown sediment originating from the horizon immediately below. It indicates a depositional setting involving flowing water and most likely was deposited during summer. Units (1)-(3) predate the Jarkov mammoth and have not produced remains of larger vertebrates. (4) The uppermost horizon, containing the remains of the Jarkov Mammoth, has a total thickness up to 160 cm, although only the lowermost part (maximum 40 cm thick) is represented in the block itself, as the overlying part had been removed during the initial excavation. It is formed by a dark to pale-brown silty clay with a texture suggesting solifluction.
and the Fishhook mammoth:

The Fishhook Mammoth is a 20,620 ± 70 BP old woolly mammoth carcass (Mol et al. 2001, MacPhee et al. 2002). It was discovered in the estuary of the Upper Taimyra River, in 1990 and some parts of the carcass were removed in 1990 and 1992. After the site had been flooded for 8 years, it was rediscovered in 2000. In May 2001 the remains were excavated under extreme cold conditions as a part of the CERPOLEX / Mammuthus programme "Who or What Killed the Mammoths"

The conclusion from the palynological analysis may be supplemented as follows: the Fishhook Mammoth had been grazing a moist, open vegetation dominated by grasses, with a lot of mosses in the ground cover. However, the presence of vegetation types of dry ground, as well as border scrub of forest tundra is also reflected by the plant remains.
For mummification it is necesary to isolate the body for instance by covering it with soil. Mud slides are often named but the where there remain where found was flat.

Both the dating and the location are not that far apart. The same eartquake mave have caused liquifaction, burying both animals.

If so then the Nikolai mammoth -if mummified- may show up with the same date:

Nikolai Mammoth

Another (partial) skeleton of a woolly mammoth was found during the 2002 field campaign by Nikolai Rudenko, working with the CERPOLEX / Mammuthus team. On the west bank of Lake Taimyr, a pair of tusks were found, together with the mandibula and some other parts of the skeleton. Other remains are still hidden in the permafrost at the locality near Cape Sablera.

It's very quiet in this place BTW.
 
  • #3
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I always found liquifaction to be one of the more interesting features of earthquakes. You can see this effect with other sediments of various particulate size, though, intuitively, sand would seem to be the easiest to be affected.

I've seen the effect (not first hand, thankfully) around slopes where earthquakes occur. The vibration of the quake excites the particles of the sediment in a way similar to liquids like water already are. Gravity then acts on the entire matrix: heavier particles falling to the bottom; the whole matrix looking for the lowest point and can flow like a river.

There are archaelogical sites in Oregon (if memory serves correct) that demonstrate this effect. Many artifacts and well-preserved trees have been unearthed, though I'd have to search my notes to find the date. It was pre-settlement by Europeans. This same quake has been correlated to a major tsunami in Japan.

Perhaps looking at sediment, terrain, and historical earthquake data, someone could create a predictive model with GIS to look for archaeological sites.

Now... I'm off to look at your link... ;)
 
  • #4
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There are archaelogical sites in Oregon (if memory serves correct) that demonstrate this effect. Many artifacts and well-preserved trees have been unearthed, though I'd have to search my notes to find the date. It was pre-settlement by Europeans. This same quake has been correlated to a major tsunami in Japan.
I read an article about well preserved trees, but in that case (Michigan) the trees were discovered by gravel/sand pit business, and scientists thought the forest must have grown up fairly quickly after a glacier receded and then sand and gravel outwash (coming in at a gentle rate, as the small needles at the tips were intact) must have covered the entire forest in a short time.
http://abcnews.go.com/sections/science/DyeHard/dyehard000223.html [Broken]
Hopefully that link still works. My computer is being uncooperative this morning and won't let me check it...

Anyway, the preserved forest is probably close but not a liquefaction candidate...
 
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  • #5
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http://geohazards.cr.usgs.gov/pacnw/paleo/reports/snohomis.htm [Broken]
Liquifaction in Washington state

http://www.liquefaction.com/

http://www.ce.washington.edu/~liquefaction/html/main.html [Broken]
More info on soil liquefaxion
 
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