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Physical Properties of Glacial and Ground Iceстатья
- Автор: Vasil'chuk Yu K.
- Сборник: Types and Properties of Water, Encyclopedia of Life Support Systems (EOLSS)
- Том: 2
- Глава в коллективной монографии
- Год издания: 2006
- Место издания: Developed under the Auspices of the UNESCO, Eolss Publishers Paris
- Первая страница: 237
- Последняя страница: 264
- Аннотация: Glacier ice covers about ten per cent of the Earth’s land surface at the present time and covered about three times as much during the ice ages. The great ice sheets are of Greenland and Antarctica. Classification of glaciers is according to ice temperature and mount of surface melting. Very few glaciers show the entire sequence: dry snow zone, percolation zone, wet-snow zone, superimposed-ice zone. The transformation of snow to ice in the percolation and wet snow zones differs from that in the dry snow zone. A superimposed – ice zone represents the extreme case. Density increase in ice results from compression of air bubbles by the overburden pressure. Crystal size increases at a constant rate if the temperature remains constant. A single ice crystal deforms under an applied stress. A single ice crystal normally deforms by gliding on its basal planes. In glaciers and ice sheets, the ice is deformed for hundreds or thousand of years, to total strains of perhaps 10 or more. Ablation includes all processes by which snow and ice are lost from the glacier. Ice in glaciers is re-crystallizing continuously. Crystal size of the ice depends on salinity. The petrofabric analysis of ground ice may help to infer growth processes and conditions. The ice grain diameter, density and shear modulus increase with the increase of the depth. Porosity of solid transparent ice is as high as 1 kg (cm3/kg) and of solid sea ice is 1 50 cm3/kg. Effective thaw heat of sea ice decreases abruptly with increase of salinity. Regelation is movement of heavy objects through the ice without any disturbances to the ice. Due to molecular thermal oscillations and defects of ice crystals the water molecules can diffuse. The electrical properties of ice are distinguished by the fact that the charge carriers in ice are protons.
- Добавил в систему: Васильчук Юрий Кириллович
Прикрепленные файлы
| № | Имя | Описание | Имя файла | Размер | Добавлен |
|---|---|---|---|---|---|
| 1. | Vasilchuk_2006_PHYSICAL_PROPERTIES_OF_GLACIAL_AND_GROUND_IC… | Vasilchuk_2006_PHYSICAL_PROPERTIES_OF_GLACIAL_AND_GROUND_IC… | 1,6 МБ | 6 ноября 2016 [vasilchuk] | |
| 2. | Vasilchuk_2006_PHYSICAL_PROPERTIES_OF_GLACIAL_AND_GROUND_IC… | Vasilchuk_2006_PHYSICAL_PROPERTIES_OF_GLACIAL_AND_GROUND_IC… | 765,0 КБ | 6 ноября 2016 [vasilchuk] |