Last Glacial Maximum records in permafrost of the East Siberian Arctic
Last Glacial Maximum records in permafrost of the East Siberian Arctic
复制标题
DOI：
10.1016/j.quascirev.2011.07.020
复制
发表时间：
2011-10
影响因子：
4
通讯作者：
S. Wetterich;N. Rudaya;V. Tumskoy;Andrei A. Andreev;T. Opel;Lutz Schirrmeister;H. Meyer
中科院分区：
文献类型：
--
作者：
S. Wetterich;N. Rudaya;V. Tumskoy;Andrei A. Andreev;T. Opel;Lutz Schirrmeister;H. Meyer
西伯利亚北极永久冻土的古生物学代用数据和低温岩石学信息保存了西白令吉亚晚第四纪气候和环境条件的记录，以及它们之间冰期-冰期和间冰期-间冰期动力学的变化。到目前为止，末次盛冰期（LGM）时期在东西伯利亚永久冻土记录中的代表性相当差。在这里，我们目前的花粉，沉积物，和地面冰稳定水同位素数据从沿海暴露在Bol'shoy Lyakhovsky岛（新西伯利亚群岛，北冰洋），反映了最冷的条件下，在Sartan期间约26和22万年BP之间，使用花粉和沉积物数据的夏季条件和稳定水同位素数据的冬季条件。花粉记录显示了一个寒冷的苔原草原植被，其特征是草花粉多于莎草花粉，而稳定同位素冰楔数据表明冬季温度极低，δ 18 O平均值约为−37‰，δD约为−290‰。结合从西部泰梅尔半岛到东部雅纳河低地的区域性末次冰期冻土记录，来自波尔绍伊-利亚霍夫斯基岛的新数据集表明，区域性末次冰期条件的出现取决于受北方冰川作用范围影响的大气环流模式。
Palaeontological proxy data and cryolithological information from Siberian Arctic permafrost preserves records of late Quaternary climate and environmental conditions in West Beringia and their variability which results from interglacial-glacial and interstadial-stadial dynamics. To date, the Last Glacial Maximum (LGM) period has been rather poorly represented in East Siberian permafrost records. Here, we present pollen, sediment, and ground-ice stable water isotope data obtained from coastal exposures on Bol’shoy Lyakhovsky Island (New Siberian Archipelago, Arctic Ocean) that mirror the coldest conditions during the Sartan period between about 26 and 22 ka BP, using pollen and sediment data for summer conditions and stable water isotope data for winter conditions. The pollen record revealed a cold tundra-steppe vegetation with characteristic predominance of grass pollen over sedge pollen while the stable isotope ice-wedges data indicate extremely cold winter temperatures with mean values of δ18O of about −37‰, δD of about −290‰. Combined with available regional LGM permafrost records that extend from the Taymyr Peninsula in the west to the Yana River lowland in the east, the new data set from Bol’shoy Lyakhovsky Island indicate that the regional appearance of LGM conditions depended on atmospheric circulation patterns that were influenced by the extent of the Northern Hemisphere glaciation.