Abstract:
Large volumes of liquid water transiently existed on the surface of Mars more than 3 billion years ago. Much of this water is hypothesized to have been sequestered in the subsurface or lost to space. We use rock physics models and Bayesian inversion to identify combinations of lithology, liquid water saturation, porosity, and pore shape consistent with the constrained mid-crust (∼11.5 to 20 km depths) seismic velocities and gravity near the InSight lander. A mid-crust composed of fractured igneous rocks saturated with liquid water best explains the existing data. Our results have implications for understanding Mars\' water cycle, determining the fates of past surface water, searching for past or extant life, and assessing in situ resource utilization for future missions.
摘要:
超过30亿年前,大量液态水暂时存在于火星表面。据推测,这些水的大部分被隔离在地下或流失到太空中。我们使用岩石物理模型和贝叶斯反演来识别岩性组合,液态水饱和度,孔隙度,和孔隙形状与InSight着陆器附近受约束的中地壳(〜11.5至20km深度)地震速度和重力一致。由液态水饱和的裂隙火成岩组成的中地壳最好地解释了现有数据。我们的结果对理解火星水循环有意义,确定过去地表水的命运,寻找过去或现存的生活,并评估未来任务的现场资源利用情况。