Seismic detection of a deep mantle discontinuity within Mars by InSight

Quancheng Huang, Nicholas C. Schmerr, Scott D. King, Doyeon Kim, Attilio Rivoldini, Ana Catalina Plesa, Henri Samuel, Ross R. Maguire, Foivos Karakostas, Vedran Lekić, Constantinos Charalambous, Max Collinet, Robert Myhill, Daniele Antonangeli, Mélanie Drilleau, Misha Bystricky, Caroline Bollinger, Chloé Michaut, Tamara Gudkova, Jessica C.E. IrvingAnna Horleston, Benjamin Fernando, Kuangdai Leng, Tarje Nissen-Meyer, Frederic Bejina, Ebru Bozdag, Caroline Beghein, Lauren Waszek, Nicki C. Siersch, John Robert Scholz, Paul M. Davis, Philippe Lognonné, Baptiste Pinot, Rudolf Widmer-Schnidrig, Mark P. Panning, Suzanne E. Smrekar, Tilman Spohn, William T. Pike, Domenico Giardini, W. Bruce Banerdt

Research output: Contribution to journalArticlepeer-review


Constraining the thermal and compositional state of the mantle is crucial for deciphering the formation and evolution of Mars. Mineral physics predicts that Mars’ deep mantle is demarcated by a seismic discontinuity arising from the pressure-induced phase transformation of the mineral olivine to its higher-pressure polymorphs, making the depth of this boundary sensitive to both mantle temperature and composition. Here, we report on the seismic detection of a midmantle discontinuity using the data collected by NASA’s InSight Mission to Mars that matches the expected depth and sharpness of the postolivine transition. In five teleseismic events, we observed triplicated P and S waves and constrained the depth of this discontinuity to be 1,006 ± 40 km by modeling the triplicated waveforms. From this depth range, we infer a mantle potential temperature of 1,605 ± 100 K, a result consistent with a crust that is 10 to 15 times more enriched in heat-producing elements than the underlying mantle. Our waveform fits to the data indicate a broad gradient across the boundary, implying that the Martian mantle is more enriched in iron compared to Earth. Through modeling of thermochemical evolution of Mars, we observe that only two out of the five proposed composition models are compatible with the observed boundary depth. Our geodynamic simulations suggest that the Martian mantle was relatively cold 4.5

Original languageEnglish (US)
Article numbere2204474119
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number42
StatePublished - Oct 18 2022
Externally publishedYes


  • interior of Mars j mantle transition zone j thermal evolution of Mars

ASJC Scopus subject areas

  • General


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