Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today
Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today
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火星上的水，含有一粒盐：今天南极冰的基础融化需要局部热异常
DOI：
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发表时间：
2019
影响因子：
5.2
通讯作者：
A. Bramson
中科院分区：
文献类型：
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作者：
M. Sori;A. Bramson
最近对来自火星快车航天器的雷达数据进行的分析将明亮的地下雷达反射解释为南极层状沉积物（SPLD）底部局部液态水的指示。然而，在该地点产生熔融所需的物理和地质条件没有量化。在这里，我们使用热物理模型来约束SPLD下产生液态水所需的参数。我们表明，在典型的火星条件下，没有浓度的盐是足以融化冰的SPLD在目前的基地。相反，即使在最有利的成分考虑下，也需要>72 mW/m2的地热热通量的局部增强。这种热流是最简单的实现，通过存在一个地下岩浆房侵位100万年前。因此，如果对观测结果的液态水解释是正确的，火星上的岩浆活动可能在最近非常活跃。
Recent analysis of radar data from the Mars Express spacecraft has interpreted bright subsurface radar reflections as indicators of local liquid water at the base of the south polar layered deposits (SPLD). However, the physical and geological conditions required to produce melting at this location were not quantified. Here we use thermophysical models to constrain parameters necessary to generate liquid water beneath the SPLD. We show that no concentration of salt is sufficient to melt ice at the base of the SPLD in the present day under typical Martian conditions. Instead, a local enhancement in the geothermal heat flux of >72 mW/m2 is required, even under the most favorable compositional considerations. This heat flow is most simply achieved via the presence of a subsurface magma chamber emplaced 100 s of kyr ago. Thus, if the liquid water interpretation of the observations is correct, magmatism on Mars may have been active extremely recently.