Spatial analyses of thermokarst lakes and basins in Yedoma landscapes of the Lena Delta
Spatial analyses of thermokarst lakes and basins in Yedoma landscapes of the Lena Delta
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DOI：
10.5194/tc-5-849-2011
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发表时间：
2011-01-01
期刊：
影响因子：
5.2
通讯作者：
Schirrmeister, L.
中科院分区：
文献类型：
--
作者：
Morgenstern, A.;Grosse, G.;Schirrmeister, L.
在西伯利亚雅库特北方的晚更新世富含冰的永久冻土层（冰复合体）中形成了独特的冰缘景观。热岩溶湖泊和热岩溶盆地与冰丰富的Yedoma高地交替。我们调查不同的热岩溶阶段的冰复杂的沉积物的勒拿河三角洲，利用遥感和地理信息技术。热岩溶湖泊的形态和空间分布Yedoma高地，盆地中的热岩溶湖泊和热岩溶盆地进行了分析，并考虑到可能依赖于救济的位置和cryolithological上下文。在这些热岩溶阶段中，Yedoma高地上的热岩溶湖泊改变了最多的富冰永冻土，但仅占研究面积的2.2%，而热岩溶盆地占20.0%。由于距离退化特征和促进湖泊排水的三角洲通道的距离缩小，未来在Yedoma高地开发大面积热岩溶的潜力有限。现有盆地中进一步的热岩溶发育仅限于已经经历了解冻、压实和旧碳活化的底层沉积物，以及最初湖泊排水后形成的沉积物。未来的热岩溶湖扩张同样受到西伯利亚大部分Yedoma地区的限制，面积约为10（6）km（2），必须考虑气候变暖情景下的水，能源和碳平衡。
Distinctive periglacial landscapes have formed in late-Pleistocene ice-rich permafrost deposits (Ice Complex) of northern Yakutia, Siberia. Thermokarst lakes and thermokarst basins alternate with ice-rich Yedoma uplands. We investigate different thermokarst stages in Ice Complex deposits of the Lena River Delta using remote sensing and geoinformation techniques. The morphometry and spatial distribution of thermokarst lakes on Yedoma uplands, thermokarst lakes in basins, and thermokarst basins are analyzed, and possible dependence upon relief position and cryolithological context is considered. Of these thermokarst stages, developing thermokarst lakes on Yedoma uplands alter ice-rich permafrost the most, but occupy only 2.2% of the study area compared to 20.0% occupied by thermokarst basins. The future potential for developing large areas of thermokarst on Yedoma uplands is limited due to shrinking distances to degradational features and delta channels that foster lake drainage. Further thermokarst development in existing basins is restricted to underlying deposits that have already undergone thaw, compaction, and old carbon mobilization, and to deposits formed after initial lake drainage. Future thermokarst lake expansion is similarly limited in most of Siberia's Yedoma regions covering about 10(6) km(2), which has to be considered for water, energy, and carbon balances under warming climate scenarios.