TY - JOUR
T1 - Seismic detection of a deep mantle discontinuity within Mars by InSight
AU - Huang, Quancheng
AU - Schmerr, Nicholas C.
AU - King, Scott D.
AU - Kim, Doyeon
AU - Rivoldini, Attilio
AU - Plesa, Ana Catalina
AU - Samuel, Henri
AU - Maguire, Ross R.
AU - Karakostas, Foivos
AU - Lekić, Vedran
AU - Charalambous, Constantinos
AU - Collinet, Max
AU - Myhill, Robert
AU - Antonangeli, Daniele
AU - Drilleau, Mélanie
AU - Bystricky, Misha
AU - Bollinger, Caroline
AU - Michaut, Chloé
AU - Gudkova, Tamara
AU - Irving, Jessica C.E.
AU - Horleston, Anna
AU - Fernando, Benjamin
AU - Leng, Kuangdai
AU - Nissen-Meyer, Tarje
AU - Bejina, Frederic
AU - Bozdag, Ebru
AU - Beghein, Caroline
AU - Waszek, Lauren
AU - Siersch, Nicki C.
AU - Scholz, John Robert
AU - Davis, Paul M.
AU - Lognonné, Philippe
AU - Pinot, Baptiste
AU - Widmer-Schnidrig, Rudolf
AU - Panning, Mark P.
AU - Smrekar, Suzanne E.
AU - Spohn, Tilman
AU - Pike, William T.
AU - Giardini, Domenico
AU - Banerdt, W. Bruce
N1 - Publisher Copyright:
Copyright © 2022 the Author(s).
PY - 2022/10/18
Y1 - 2022/10/18
N2 - 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
AB - 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
KW - interior of Mars j mantle transition zone j thermal evolution of Mars
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U2 - 10.1073/pnas.2204474119
DO - 10.1073/pnas.2204474119
M3 - Article
C2 - 36215469
AN - SCOPUS:85139526193
SN - 0027-8424
VL - 119
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 42
M1 - e2204474119
ER -