GIS-based Maps and Area Estimates of Northern Hemisphere Permafrost Extent during the Last Glacial Maximum
GIS-based Maps and Area Estimates of Northern Hemisphere Permafrost Extent during the Last Glacial Maximum
复制标题
DOI：
10.1002/ppp.1851
复制
发表时间：
2016-01-01
影响因子：
5
通讯作者：
Vandenberghe, Jef
中科院分区：
文献类型：
--
作者：
Lindgren, Amelie;Hugelius, Gustaf;Vandenberghe, Jef
本研究提出了基于GIS的估计在末次盛冰期（LGM）期间，在北方环极地区的冻土范围，根据以前出版的地图和汇编的形式的冰楔伪形和残留的砂楔的现场证据的审查。我们把重点放在被认为是位于沿着过去的永久冻土南部边界地区的实地证据地点。我们提出了不同的重建多年冻土范围，面积估计暴露的海架，冰盖和冰川，以评估最小，可能和最大的多年冻土范围的地区。基于GIS的这些经验重建的映射使我们能够估计LGM期间北方永久冻土的可能面积为3450万km（2）（其中包括暴露的沿海海架上的470万km（2）永久冻土）。最小估计值为3270万km（2），最大估计值为3530万km（2）。据估计，LGM永久冻土的范围在c。9.1 1170万公里（2），比目前陆地上的面积（2360万公里（2））大。然而，240万公里（2）的丧失的土地面积目前仍然是水下海岸架上的海底永久冻土。因此，在末次盛冰期期间，北方环极地区的末次盛冰期永久冻土范围比现在大了约33%。自末次冰期以来，北方永久冻土的净损失是由于欧亚大陆大部分地区永久冻土的消失，而北美以前被劳伦泰德冰盖覆盖的地区的收益并没有弥补这一损失。版权所有（c）2015约翰威利父子有限公司
This study presents GIS-based estimates of permafrost extent in the northern circumpolar region during the Last Glacial Maximum (LGM), based on a review of previously published maps and compilations of field evidence in the form of ice-wedge pseudomorphs and relict sand wedges. We focus on field evidence localities in areas thought to have been located along the past southern border of permafrost. We present different reconstructions of permafrost extent, with areal estimates of exposed sea shelf, ice sheets and glaciers, to assess areas of minimum, likely and maximum permafrost extents. The GIS-based mapping of these empirical reconstructions allows us to estimate the likely area of northern permafrost during the LGM as 34.5 million km(2) (which includes 4.7 million km(2) of permafrost on exposed coastal sea shelves). The minimum estimate is 32.7 million km(2) and the maximum estimate is 35.3 million km(2). The extent of LGM permafrost is estimated to have been between c. 9.1 to 11.7 million km(2) larger than its current extent on land (23.6 million km(2)). However, 2.4 million km(2) of the lost land area currently remains as subsea permafrost on the submerged coastal shelves. The LGM permafrost extent in the northern circumpolar region during the LGM was therefore about 33 percent larger than at present. The net loss of northern permafrost since the LGM is due to its disappearance in large parts of Eurasia, which is not compensated for by gains in North America in areas formerly covered by the Laurentide ice sheet. Copyright (c) 2015 John Wiley & Sons, Ltd.