Article Dans Une Revue Science Année : 2021

Seismic detection of the martian core

Amir Khan
Martin Schimmel
Constantinos Charalambous
Jessica Irving
Ross Maguire
Anna Horleston
W. Thomas Pike

Résumé

Clues to a planet’s geologic history are contained in its interior structure, particularly its core. We detected reflections of seismic waves from the core-mantle boundary of Mars using InSight seismic data and inverted these together with geodetic data to constrain the radius of the liquid metal core to 1830 ± 40 kilometers. The large core implies a martian mantle mineralogically similar to the terrestrial upper mantle and transition zone but differing from Earth by not having a bridgmanite-dominated lower mantle. We inferred a mean core density of 5.7 to 6.3 grams per cubic centimeter, which requires a substantial complement of light elements dissolved in the iron-nickel core. The seismic core shadow as seen from InSight’s location covers half the surface of Mars, including the majority of potentially active regions—e.g., Tharsis—possibly limiting the number of detectable marsquakes.

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hal-03365934 , version 1 (05-10-2021)

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Simon Stähler, Amir Khan, W. Bruce Banerdt, Philippe Lognonné, Domenico Giardini, et al.. Seismic detection of the martian core. Science, 2021, 373 (6553), pp.443-448. ⟨10.1126/science.abi7730⟩. ⟨hal-03365934⟩
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