Area and volume of mid-latitude glacier-like forms on Mars
Area and volume of mid-latitude glacier-like forms on Mars
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火星上中纬度冰川状结构的面积和体积
DOI：
10.1016/j.epsl.2018.11.031
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发表时间：
2019
影响因子：
5.3
通讯作者：
Brough S
中科院分区：
文献类型：
--
作者：
Brough S
虽然已经在火星中纬度地区发现了大量的冰盖，但关于这些冰块的形成、现在和以前的体积以及动态演化仍存在不确定性。在这里，我们首次从系统的人口规模制图和体积分析中对火星类冰川形式(GLF)的冰量进行了全面估计。1243个GLF的轮廓是从6m/像素的上下文照相机(CTX)图像中手动勾画出来的，并且每个GLF的体积使用体积-面积比例方法来确定。结果表明，GLF的比表面积为11344±393km2，总体积为1744±441km2。使用两个终端成员的冰体积密度为30%(孔隙冰)和90%(碎屑覆盖的冰川冰)的情景，我们计算出GLF中包含的冰体积在523±132千米(480±121GT)到1570±397千米3(1439±364GT)之间，相当于全球平均水层3至10毫米厚。我们参考火星轨道激光高度计(MOLA)的数字高程模型，研究了每个GLF的局部地形设置。我们的分析表明，在全球范围内，GLF平均在纬度36°和坡度2至8°之间较大。在北半球，海拔在500-2500米之间的GLF和在南半球北侧的GLF也平均较大。观测到的GLF地貌和体积分布的空间格局表明，区域和当地的气象和地形条件对GLF冰的积累和/或保存起着重要作用。假设一个典型的大倾角气候漂移的−净累积率为10 mm，我们估计至少需要13ka的周期才能计算出平均计算的∼130m的冰厚，这一周期完全在一个大倾角周期(20-40ka)的时间范围内，这表明目前的GLF量可能是在一次气候漂移中形成的。
Although a substantial ice cover has been identified within the mid-latitudes of Mars, there is uncertainty regarding the formation, current and former volume, and dynamic evolution of these ice masses. Here, we present the first comprehensive ice volume estimate of martian glacier-like forms (GLFs) from systematic population scale mapping and volumetric analysis. The outlines of 1243 GLFs were manually delineated from 6 m per pixel Context Camera (CTX) images and the volume of each determined using a volume–area scaling approach. Our results show that GLFs cover a surface area of 11344 ± 393 km2and have a total volume of 1744 ± 441 km3. Using two end-member scenarios for ice concentration by volume of 30% (pore ice) and 90% (debris-covered glacier ice), we calculate the volume of ice contained within GLFs to be between 523 ± 132 km3(480 ± 121 Gt) and 1570 ± 397 km3(1439 ± 364 Gt), equivalent to a mean global water layer 3 to 10 mm thick. We investigate the local topographic setting of each GLF by reference to the Mars Orbiter Laser Altimeter (MOLA) digital elevation model. Our analysis reveals that globally GLFs are on average larger in latitudes >36° and on slopes between 2 and 8°. In the northern hemisphere GLFs between 500 and 2500 m in elevation and in the southern hemisphere GLFs with a northern aspect are also larger on average. The observed spatial patterns of GLF landform and volume distribution suggests that regional to local meteorological and topographical conditions play an important role in GLF ice accumulation and/or preservation. Assuming a net accumulation rate of 10 mm a−1typical of climatic excursions with high obliquity, we estimate a period of at least 13 ka is required to yield the average calculated GLF ice thickness of ∼130 m. Such a period is well within the timeframe of a high obliquity cycle (20–40 ka), suggesting that the current GLF volume could have formed during a single climate excursion.
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DOI：
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发表时间：
2014
期刊：
影响因子：
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作者：
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DOI：
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发表时间：
2012
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DOI：
--
发表时间：
2008
期刊：
影响因子：
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作者：
J. Dickson;J. Head;D. Marchant
通讯作者：
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影响因子：
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作者：
J. Plaut;G. Picardi;A. Safaeinili;A. Ivanov;S. Milkovich;A. Cicchetti;Wlodek Kofman;J. Mouginot;W. Farrell;R. Phillips;S. Clifford;A. Frigeri;R. Orosei;C. Federico;I. Williams;D. Gurnett;E. Nielsen;T. Hagfors;E. Heggy;E. Stofan;D. Plettemeier;T. Watters;C. Leuschen;P. Edenhofer
通讯作者：
J. Plaut;G. Picardi;A. Safaeinili;A. Ivanov;S. Milkovich;A. Cicchetti;Wlodek Kofman;J. Mouginot;W. Farrell;R. Phillips;S. Clifford;A. Frigeri;R. Orosei;C. Federico;I. Williams;D. Gurnett;E. Nielsen;T. Hagfors;E. Heggy;E. Stofan;D. Plettemeier;T. Watters;C. Leuschen;P. Edenhofer
影响因子：
64.8
作者：
Head, JW;Mustard, JF;Marchant, DR
通讯作者：
Marchant, DR