Thermokarst in Siberian ice‐rich permafrost: Comparison to asymmetric scalloped depressions on Mars
Thermokarst in Siberian ice‐rich permafrost: Comparison to asymmetric scalloped depressions on Mars
复制标题
西伯利亚富含冰的永久冻土中的热岩溶：与火星上不对称扇形凹陷的比较
DOI：
10.1029/2010je003640
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发表时间：
2010
影响因子：
--
通讯作者：
Lutz Schirrmeister
中科院分区：
文献类型：
--
作者：
M. Ulrich;A. Morgenstern;F. Günther;D. Reiss;K. Bauch;E. Hauber;S. Rössler;Lutz Schirrmeister
[1]在地球上，含冰量高的永久冻土带的融化导致大量地表沉降，形成典型的大型热岩溶洼地。热岩溶洼地内的斜坡不对称表明侧向生长，这是由于沿这些斜坡的热侵蚀和重量质量浪费而发生的。有人提出，火星上无框的、形状不对称的洼地（称为扇形洼地）是由日晒驱动的地面冰升华形成的。我们研究了西伯利亚北极冰复合体沉积物中的大型热岩溶洼地，作为火星富含挥发物的地幔沉积物中扇贝洼地的陆地模拟物。我们的野外研究、日照模拟和地貌分析结果表明，北方向的侧向热岩溶发育。这一结论很明显，因为南坡的坡度角更陡。日照和地表温度是直接影响热岩溶边坡稳定性和陡度的关键因素。利用高分辨率（高分辨率成像科学实验，Context Camera）和热红外（热发射成像系统）卫星数据对Utopia Planitia火星扇形洼地进行了对比分析。通过直接类比，我们认为火星上的侧向扇形凹陷发育主要是在向赤道方向的陡峭的面向极地的斜坡上被迫形成的。日晒模型证实，这一定发生在过去的10毫安，当时的轨道倾角比现在更高。如果轨道既高度倾斜又高度偏心，并且/或者火星的夏天正好是近日点，那么发展就会最大化。相对较短的地表冰升华增加甚至融化的事件导致了陡峭的朝极斜坡上的快速滑坡过程。
[1] On Earth, the thawing of permafrost deposits with high-ground ice content results in massive surface subsidence and the formation of characteristic large thermokarst depressions. Slope asymmetries within thermokarst depressions suggest lateral growth, which occurs due to thermoerosion and gravimetric mass wasting along these slopes. It has been proposed that rimless, asymmetrically shaped depressions (called scalloped depressions) on Mars were formed by insolation-driven ground ice sublimation. We investigated a large thermokarst depression in ice complex deposits in the Siberian Arctic as a terrestrial analogue for scalloped depressions in Martian volatile-rich mantle deposits. Our results from field studies, insolation modeling, and geomorphometric analyses suggest lateral thermokarst development in a northern direction. This conclusion is obvious due to steeper slope angles of the south facing slopes. Insolation and surface temperatures are crucial factors directly influencing thermokarst slope stability and steepness. Comparative analyses of Martian scalloped depressions in Utopia Planitia were conducted using high-resolution (High-Resolution Imaging Science Experiment, Context Camera) and thermal infrared (Thermal Emission Imaging System) satellite data. By direct analogy, we propose that the lateral scalloped depression development on Mars was primarily forced on the steep pole-facing slopes in the equator-ward direction. Insolation modeling confirms that this must have happened in the last 10 Ma during an orbital configuration of higher obliquity than today. Development would have been maximized if the orbit was both highly oblique and highly eccentric, and/or the Martian summer coincided with perihelion. Relatively short events of increasing sublimation or even thawing of ground ice led to fast slumping processes on the steep pole-facing slopes.
阿瑞斯山谷的西斯皮利亚赤道热喀斯特湖是火星上短暂温暖条件的证据
影响因子：
5.8
作者：
Warner N
通讯作者：
Warner N