Beyond InSight: Ocean-generated seismic signals elsewhere in the Solar System

SIMON STÄHLER*1, MARK PANNING2, RALPH LORENZ3, CÉLINE HADZIIOANNOU4, STEVE VANCE2

1Institute for Geophysics, ETH Zürich, Switzerland (staehler@erdw.ethz.ch) 2Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA 3Applied Physics Laboratory, The Johns Hopkins University, Laurel, USA 4Institute for Geophysics, University of Hamburg, Germany

Since the Viking mission, no successful planetary lander mission has been equipped with a seismometer. This is unfortunate, given that most of the knowledge about Earth’s deep interior was derived from seismological observations. The InSight mission will install two broadband seismometers on Mars, exactly two weeks after this conference, if entry, descent and landing are successful. Analyses of these exciting new data will be able harness the enormous progress that has taken place in the last 40 years in seismological signal processing.

What will happen next? Current NASA plans for landers on Europa and Titan include seismometers, which would allow measurements of the radial depths of compositional interfaces in the ice, the ocean and the deeper interior. We present estimations of Europa’s seismic wavefield using spectral-element simulations, taking into account seismic sources from tidal ice cracking and ocean circulation on Europa and Titan, as well as wind-generated microseism in the methane lakes on Titan’s surface.

The results show that Earth is not the only place in the Solar System where ocean-generated seismic noise exists and that it could be a valuable remote sensing tool for future landers without a concurrent orbiter.

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