Séminaire ISTerre

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InSight sur Mars : Une année Martienne de découvertes sismiques

lundi 27 septembre 2021 - 11h00

Philippe Lognonné - Institut de Physique du globe de Paris
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In 2018, the NASA InSight mission brought a highly sophisticated seismometer to Mars with three very broad band sensors and three sensors optimized short period signals. Almost continuous monitoring of the seismic activity of Mars has confirmed that the planet is intermediate in activity between the larger Earth and the smaller Moon. Even if a lot of efforts were made on the installation, SEIS remains sensitive to the wind and atmosphere, not only because of the lander vicinity, but just because the atmosphere is a major source of ground deformation. Extremely low noise levels are however observed in the late afternoon, which has led to the detection of more than 500 events, including several 10s of low frequency teleseismic events. The interpretation of the data has provided a layering in the crust underneath the landing site, by using atmospheric sources for the very shallow surface and receiver functions from Marsquakes for the upper crust. SEIS is now constraining deeper structures with the largest Marsquakes detected, corresponding to Earth magnitude in the range of 3-3.5. This includes the temperature profile in the mantle and core. The talk will conclude on the perspective of future planetary seismology, including some lessons learned from InSIght. Lien Zoom : https://univ-grenoble-alpes-fr.zoom.us/j/97488574760?pwd=UlhHZGxwZUMxS3hOMXhLNFZVM2ZRQT09

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Equipe organisatrice : Grands Séminaires ISTerre

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères