Tectonics of Cerberus Fossae unveiled by marsquakes

TL;DR

This study uses Marsquake data from the InSight mission to reveal that the Cerberus Fossae region is a key tectonic and volcanic activity zone on Mars, with seismicity linked to recent volcanic processes and crustal deformation.

Contribution

It provides the first detailed seismic analysis of Cerberus Fossae, linking marsquake locations and characteristics to volcanic activity and crustal structure on Mars.

Findings

LF and HF marsquakes are located on different parts of Cerberus Fossae.

LF quakes suggest a warm, weak source region at 15-50 km depth.

Seismic activity accounts for at least half of Mars' total seismic moment.

Abstract

The InSight mission has measured Mars' seismicity since February 2018 and has allowed to investigate tectonics on another planet. Seismic data shows that most of the widely distributed surface faults are not seismically active, and that seismicity is mostly originating from a single graben structure, the Cerberus Fossae. We show that both major families of marsquakes characterized by low and high frequency content, LF and HF events respectively, are located on central and eastern parts of this graben system. LF hypocenters are located at 15-50 km depth and the spectral character suggests a structurally weak, potentially warm source region consistent with recent volcanic activity at those depths. HF marsquakes occur in the brittle, shallow part of the crust and might originate in fault planes associated with the graben flanks. Estimated magnitudes are between 2.8 and 3.8, resulting in a total seismic moment release within Cerberus Fossae of 1.4-5.6 $\times10^{15}$ Nm/yr, or at least half of the observed value of the entire planet. Our findings confirm that Cerberus Fossae represents a unique tectonic setting shaped by current day volcanic processes, with implications for minimum local heat flow.