The Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) mission arrives on Mars in November 2018. In anticipation of its arrival, a group of researchers led by Dr. Ana-Catalina Plesa have focused on the seismic experiments, which aim to probe the distribution of seismicity across Mars. They have conducted a series of numerical models based on convective stresses associated with cooling and planetary contraction. Their estimates [published in Geophysical Research Letters] place the total seismicity on Mars somewhere between that of the Earth and the Moon…
[From the Discussion section of the paper:] The upcoming InSight measurements will help determine the amount and distribution of Martian seismicity by monitoring the seismic activity for one Martian year. Although the mission provides only one seismic station, the presence of depth phases and the relative amplitude of surface waves with respect to body waves will provide constraints on the depth distribution of seismic sources.
On Earth, essentially all seismicity below the Moho is connected to plate boundaries and subduction of cold lithosphere. Mars, on the other hand, is a one‐plate planet and so far deep seismicity was not expected to exist. This view, however, is challenged by the HC models presented here, which suggest that the seismogenic volume could extend to depths of about 400 km, if the base of the seismogenic layer is marked by the 1073 K isotherm… [More at links]