Verifying single-station seismic approaches using Earth-based data: Preparation for data return from the InSight mission to Mars

The planned InSight mission will deliver a single seismic station containing 3-component broadband and short-period sensors to the surface of Mars in 2016. While much of the progress in understanding the Earth and Moon's interior has relied on the use of seismic networks for accurate location of sources, single station approaches can be applied to data returned from Mars in order to locate events and determine interior structure. In preparation for the data return from Insight, we use a terrestrial dataset recorded at the Global Seismic Network station BFO, located at the Black Forest Observatory in Germany, to verify an approach for event location and structure determination based on recordings of multiple orbit surface waves, which will be more favorable to record on Mars than Earth due to smaller planetary radius and potentially lower background noise. With this approach applied to events near the threshold of observability on Earth, we are able to determine epicentral distance within approximately 1 degrees (corresponding to similar to 60 km on Mars), and origin time within similar to 30 s. With back azimuth determined from Rayleigh wave polarization, absolute locations are determined generally within an aperture of 10 degrees, allowing for localization within large tectonic regions on Mars. With these locations, we are able to recover Earth mantle structure within +/- 5% (the InSight mission requirements for martian mantle structure) using ID travel time inversions of P and S travel times for datasets of only 7 events. The location algorithm also allows for the measurement of great-circle averaged group velocity dispersion, which we measure between 40 and 200 s to scale the expected reliable frequency range of the InSight data from Earth to Mars data. Using the terrestrial data, we are able to resolve structure down to similar to 200 km, but synthetic tests demonstrate we should be able to resolve martian structure to similar to 400 km with the same frequency content given the smaller planetary size. (C) 2014 Elsevier Inc. All rights reserved.