Seismic detection of the martian core

Research areas:
Year:
2021
Authors:
  • Simon C. Stähler
  • Amir Khan
  • W. Bruce Banerdt
  • Philippe Lognonné
  • Domenico Giardini
  • Savas Ceylan
  • Mélanie Drilleau
  • A. Cecilia Duran
  • Raphaël F. Garcia
  • Quancheng Huang
  • Doyeon Kim
  • Vedran Lekic
  • Henri Samuel
  • Martin Schimmel
  • Nicholas Schmerr
  • David Sollberger
  • Éléonore Stutzmann
  • Zongbo Xu
  • Daniele Antonangeli
  • Constantinos Charalambous
  • Paul M. Davis
  • Jessica C. E. Irving
  • Taichi Kawamura
  • Martin Knapmeyer
  • Ross Maguire
  • Angela G. Marusiak
  • Mark P. Panning
  • Clément Perrin
  • Ana-Catalina Plesa
  • Attilio Rivoldini
  • Cédric Schmelzbach
  • Géraldine Zenhäusern
  • Éric Beucler
  • John Clinton
  • Nikolaj Dahmen
  • Martin van Driel
  • Tamara Gudkova
  • Anna Horleston
  • W. Thomas Pike
  • Matthieu Plasman
  • Suzanne E. Smrekar
Journal:
Science
Volume:
373
Number:
6553
Pages:
443-448
ISSN:
0036-8075
BibTex:
Abstract:
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.