|
ИСТИНА |
Войти в систему Регистрация |
Интеллектуальная Система Тематического Исследования НАукометрических данных |
||
Climate Modelling by Chainsaw – Ice Wedges as a Winter Climate Archiveстатья
- Авторы: Meyer H., Opel Th, Dereviagin A.Yu
- Сборник: “20 лет наземных исследований в Сибирской Арктике. История экспедиций в дельте Лены”
- Глава в коллективной монографии
- Год издания: 2018
- Место издания: BerlinDruck GmbH + Co KG, Achim, 2018 Berlin
- Первая страница: 111
- Последняя страница: 114
- Аннотация: Ice wedges are wide spread and landscape-forming features of permafrost landscapes. They are often wedge-shaped, as the name says, and visible at coastal or riverine cliffs as huge, impressive ice blocks, mostly 2-3 m wide (reaching up to 6 m) and propagating several, sometimes tens of meters, into the ground, narrowing downwards. They are formed by frost-cracking processes, where during winter periods cooling leads to shrinkage of the frozen ground and to the opening of a frost crack, which is subsequently filled by snow and snow melt water during spring. The very negative soil temperatures of sometimes -10°C and below lead to immediate freezing of this melt water inducing the formation of an ice vein. This process is repeated year by year and an ice wedge is formed – composed of many single vertical ice veinlets containing a chemical signature of the preceding winter snow. Ice wedges are able to capture specifically the winter season, and they show for the Lena Delta a natural gradual warming over the past 7.000 years towards a recent maximum as shown in a much-noticed publication). This contrasts with long-term Holocene summer cooling seen in many other Arctic proxies (i.e. in pollen), but confirms what paleoclimate model simulations predicted.
- Добавил в систему: Деревягин Александр Юрьевич