Recent tectonic activity on Pluto driven by phase changes in the ice shell
Recent tectonic activity on Pluto driven by phase changes in the ice shell
复制标题
冰壳相变驱动的冥王星近期构造活动
DOI：
10.1002/2016gl069220
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发表时间：
2016
影响因子：
5.2
通讯作者：
E. Parmentier
中科院分区：
文献类型：
--
作者：
N. Hammond;A. Barr;E. Parmentier
新视野号宇宙飞船已经发现了冥王星表面地质活动的证据，包括其水冰基岩的伸展构造变形（参见摩尔等人）。一种可能驱动伸展构造活动的机制是由于海洋部分冻结而导致的全球表面扩张。我们使用更新的冥王星物理特性，并模拟其热演化，以了解可能的地下海洋的生存。当岩石的热导率小于3 W m−1 K−1时，海洋会形成并至少部分冻结，导致冰壳中的近期拉伸应力。在海洋冻结和冰壳厚度超过260公里的情况下，冰II形成并导致全球体积收缩。由于没有证据表明最近的挤压构造特征，我们认为冰II还没有形成，冥王星的海洋可能一直存活到今天。
The New Horizons spacecraft has found evidence for geologic activity on the surface of Pluto, including extensional tectonic deformation of its water ice bedrock see Moore et al. (2016). One mechanism that could drive extensional tectonic activity is global surface expansion due to the partial freezing of an ocean. We use updated physical properties for Pluto and simulate its thermal evolution to understand the survival of a possible subsurface ocean. For thermal conductivities of rock less than 3 W m−1 K−1, an ocean forms and at least partially freezes, leading to recent extensional stresses in the ice shell. In scenarios where the ocean freezes and the ice shell is thicker than 260 km, ice II forms and causes global volume contraction. Since there is no evidence for recent compressional tectonic features, we argue that ice II has not formed and that Pluto's ocean has likely survived to present day.