학술논문

MSS/1: Single‐Station and Single‐Event Marsquake Inversion.
Document Type
Article
Source
Earth & Space Science. Dec2020, Vol. 7 Issue 12, p1-37. 37p.
Subject
*SEISMIC event location
*SEISMIC wave velocity
*SURFACE waves (Seismic waves)
*UNCERTAINTY
*SEISMOGRAMS
Language
ISSN
2333-5084
Abstract
SEIS, the seismometer of the InSight mission, which landed on Mars on 26 November 2018, is monitoring the seismic activity of the planet. The goal of the Mars Structure Service (MSS) is to provide, as a mission product, the first average 1‐D velocity model of Mars from the recorded InSight data. Prior to the mission, methodologies have been developed and tested to allow the location of the seismic events and estimation of the radial structure, using surface waves and body waves arrival times, and receiver functions. The paper describes these validation tests and compares the performance of the different algorithms to constrain the velocity model below the InSight station and estimate the 1‐D average model over the great circle path between source and receiver. These tests were performed in the frame of a blind test, during which synthetic data were inverted. In order to propagate the data uncertainties on the output model distribution, Bayesian inversion techniques are mainly used. The limitations and strengths of the methods are assessed. The results show the potential of the MSS approach to retrieve the structure of the crust and underlying mantle. However, at this time, large quakes with clear surface waves have not yet been recorded by SEIS, which makes the estimation of the 1‐D average seismic velocity model challenging. Additional locatable events, especially at large epicentral distances, and development of new techniques to fully investigate the data, will ultimately provide more constraints on the crust and mantle of Mars. Key Points: In the framework on the InSight mission, a synthetic seismogram using a 3‐D crust and a 1‐D velocity model below is proposedThis signal is used to present inversion methods, relying on different parameterizations, to constrain the 1‐D structure of MarsThe results demonstrate the feasibility of the strategy to retrieve VS in the crust, and a fairly good estimation of the Moho depth [ABSTRACT FROM AUTHOR]