Biological Properties of Glacial and Ground Ice

Vasil’chuk, Y.K.; Vasil’chuk, A.C.

Авторы: Vasil’chuk Yu K., Vasil’chuk A.C.
Сборник: Encyclopedia of Life Support Systems (EOLSS). Ed.: M.G. Khublaryan
Том: 2
Год издания: 2009
Первая страница: 295
Последняя страница: 318
Аннотация: The main biologic property of the ice is the preserving of biologic subjects. Biologic properties of ice can be distinguished by inclusion of biologic subjects and biologically active substations. In the future glacier and ground ices might be used as a source preserving genetic material such as pollen and spores, seeds, microbes and also preserving carcasses of prehistoric animals. The ice subsurface constitutes special niche. Rich algae flora is growing at interface of snow and ice on broken and drifting ice floe in Antarctic and Arctic. Pollen and spores have been determined in number of key-cryospheric subjects, such as mountain glaciers, Arctic Ice caps in snow cover marine and river ice. Pollen and spores are relatively abundant in glacier ice, but in pollen concentration in polar snow cover is very low. Pollen and spores are common in ice bodies of different origin in permafrost areas. Enzymes may be classified as biologically active substance in the ice. Proteolytic activity is activity of albumen splitting; amylolytic activity is activity of starch splitting. These kinds of enzymatic activity may be determined in sea water, bay, rivers, season melted layer and also all variety of surface and ground ice, such as segregated ice, ice wedges, ice sheets, ice-floes, etc. Numerous and various viable microorganisms such as: prokaryotes, green algae, cyanobacteria, actinomicetes, fungi and yeast are found in the snow and pure marine, river, lake and ground ice. The findings of ancient people are very rare but of great interest because they give us the possibility to obtain valuable information about ancient people life. Mummies were discovered in mountain glaciers of Alps, Andes and British Columbia. Mammoth fauna founds are also very informative and interesting. More than 10 findings of fossils mammoth’s whole carcasses have been discovered in Siberian permafrost. Once more interesting aspect of ground glaciation existing is finding of extinct large mammalians in permafrost. More than ten fossil mammoth’ whole carcasses have been discovered in Siberian permafrost. They are Yuribey Mammoth (Gydan Peninsula), Gydan Mammoth (Gyda River), Pyasina Mammoth (Taimyr Peninsula), Mochovaya Mammoth (Taimyr Peninsula), Shrenk’ Mammoth (Taimyr Peninsula), Chekurovka Mammoth (Lower Lena River), Lena River delta (Bykovsky) mammoth, Beryosovka mammoth (Upper Kolyma), Shandrin mammoth, Kirgilyakh mammoth baby (Dima), Mammoth from Lyakhovskiy Bol'shoi Island, Tirekhtyakh River Mammoth, Enmynveem (Chukotka Peninsula) Mammoth (here found separately mammoth soft tissues). It is obvious that an original burial of whole mammoth carcass is an accidental process. It is required the coincidence of several conditions. The first, a carcass must be covered by sediment very quickly or isolated from carnivores by another way very fast. The second is, virtually instant temperature lowering of preserving surroundings. The third, the subsequent transition in perennially frozen condition must be quick enough. A combination of the circumstances is very rare. Possible place for the mammoth burial can be talus and alluvial fans, high icy undermined terraces, and rarer, thermokarst holes in places of massive ground ice under local thermoerosion. The buried mammoths' are most often found in polygonal ice wedge complex deposits. The southern limits of mammoths’ aerial extent coincide with the southern limits of polygonal wedge structures. The latter are reconstructed on casts distribution. The isotope records in syngenetic ice wedge accompanying the mammoths' fossils allowed reconstructing winter temperatures during mammoths' time. The all interval of delta18O in syngenetic ice wedge which formed 40–10 ka B.P in North of the Western Siberia changed from –24 to –21‰, in Northern Yakutia from –34 to –29‰ and in Northern Chukotka from –32 to –29‰. The source for these ice wedges formation was the melt snow, therefore the oxygen isotope record is an indicator of winter precipitation temperatures. Using the obtained (Vasil'chuk, 1992) relationship between mean winter temperatures and oxygen isotope records it is possible to evaluate the winter conditions in Northern Eurasia 40–10 ka BP as very cold and stable
Добавил в систему: Васильчук Юрий Кириллович

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