An assessment of evidence for pingos on Mars using HiRISE
An assessment of evidence for pingos on Mars using HiRISE
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DOI：
10.1016/j.icarus.2009.02.020
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发表时间：
2010-01-01
期刊：
影响因子：
3.2
通讯作者：
McEwen, Alfred S.
中科院分区：
文献类型：
--
作者：
Dundas, Colin M.;McEwen, Alfred S.
冰丘是一种由冰核构成的小山丘，由高压水注入和冻结而成。火星上冰丘的可能性特别令人感兴趣，因为它与液态水有关。我们使用高分辨率成像科学实验（HiRISE）相机的图像系统地搜索候选冰丘。由于冰丘预计会发展表面裂缝，由于扩展的冻结地面的冰芯，我们已经寻找断裂的功能，并确定了各种土丘。这些特征仅限于火星中纬度地区，在那里沟壑也是最常见的。所观察到的断裂土丘有各种形态，可能是多个起源。在南半球沟壑纵横的陨石坑地面上发现的孤立的断裂土丘与陆地冰丘的一般形态特征相匹配，是火星冰丘的最佳候选者，但目前还没有直接证据表明冰核的存在，而且很难产生必要的水量，因此仍应谨慎解释这些特征。其他破碎的土丘似乎更有可能是一个不寻常的地幔层或可能的热岩溶结构的侵蚀遗迹。乌托邦的平顶土丘在断裂模式和纬向分布等方面与冰丘一致，但在形状和环境等方面有所不同。虽然我们不排除冰丘的起源，但我们更倾向于这些神秘特征的侵蚀模型。(C)2009 Elsevier Inc. All rights reserved.
Pingos are small hills with cores of ice, formed by injection and freezing of pressurized water. The possibility of pingos on Mars is of particular interest because of the associated implications for liquid water. We have systematically searched for candidate pingos using images from the High Resolution Imaging Science Experiment (HiRISE) camera. Since pingos are expected to develop surface fractures due to extension of the frozen ground over the ice core, we have searched for fractured features and identified a variety of mounds. These features are confined to the martian mid-latitudes, in the bands where gullies are also most common. The observed fractured mounds have a variety of morphologies and are likely of multiple origins. Isolated fractured mounds found on the floors of gullied craters in the southern hemisphere match the general morphologic characteristics of terrestrial pingos and are the best candidates for martian pingos, but there is currently no direct evidence for presence of ice cores and it is difficult to produce the necessary water volumes, so these features should still be interpreted with caution. Other fractured mounds appear more likely to be erosional remnants of an unusual mantling layer or possibly thermokarst structures. Flat-topped mounds in Utopia have some characteristics (fracture pattern and latitudinal distribution) consistent with pingos but differ in other aspects such as shape and setting. While we do not rule out a pingo origin, we prefer an erosional model for these enigmatic features. (C) 2009 Elsevier Inc. All rights reserved.