Seismic discontinuity in the Martian crust possibly caused by water-filled cracks

Abstract

Recent seismic data acquired by the InSight lander have revealed seismic discontinuities in the Martian crust that have been interpreted as sharp transitions in porosity or chemical composition. Here we propose an alternative model in which the transition from dry cracks to water-filled cracks could explain the observed seismic discontinuity in the Martian crust. Our model can explain sharp increases in seismic velocity and Vp/Vs at ∼10 km depth with no associated changes in porosity or chemical composition. The present model suggests the local existence of liquid water in the Martian crust, which could potentially serve as a subsurface habitat for life.