TY - JOUR
T1 - First observations of core-Transiting seismic phases on Mars
AU - Irving, Jessica C.E.
AU - Lekic, Vedran
AU - Durán, Cecilia
AU - Drilleau, Mélanie
AU - Kim, Doyeon
AU - Rivoldini, Attilio
AU - Khan, Amir
AU - Samuel, Henri
AU - Antonangeli, Daniele
AU - Bruce Banerdt, William
AU - Beghein, Caroline
AU - Bozdagk, Ebru
AU - Ceylan, Savas
AU - Charalambous, Constantinos
AU - Clinton, John
AU - Davis, Paul
AU - Garcia, Raphaël
AU - Giardini, Domenico
AU - Catherine Horleston, Anna
AU - Huang, Quancheng
AU - Hurst, Kenneth J.
AU - Kawamura, Taichi
AU - King, Scott D.
AU - Knapmeyer, Martin
AU - Li, Jiaqi
AU - Lognonné, Philippe
AU - Maguire, Ross
AU - Panning, Mark P.
AU - Plesa, Ana Catalina
AU - Schimmel, Martin
AU - Schmerr, Nicholas C.
AU - Stählerc, Simon C.
AU - Stutzmann, Eleonore
AU - Xu, Zongbo
N1 - Publisher Copyright:
© 2023 National Academy of Sciences. All rights reserved.
PY - 2023/5/2
Y1 - 2023/5/2
N2 - We present the first observations of seismic waves propagating through the core of Mars. These observations, made using seismic data collected by the InSight geophysical mission, have allowed us to construct the first seismically constrained models for the elastic properties of Mars core. We observe core-Transiting seismic phase SKS from two farside seismic events detected on Mars and measure the travel times of SKS relative to mantle traversing body waves. SKS travels through the core as a compressional wave, providing information about bulk modulus and density. We perform probabilistic inversions using the core-sensitive relative travel times together with gross geophysical data and travel times from other, more proximal, seismic events to seek the equation of state parameters that best describe the liquid iron-Alloy core. Our inversions provide constraints on the velocities in Mars core and are used to develop the first seismically based estimates of its composition. We show that models informed by our SKS data favor a somewhat smaller (median core radius = 1,780 to 1,810 km) and denser (core density = 6.2 to 6.3 g/cm3) core compared to previous estimates, with a P-wave velocity of 4.9 to 5.0 km/s at the core mantle boundary, with the composition and structure of the mantle as a dominant source of uncertainty. We infer from our models that Mars core contains a median of 20 to 22 wt% light alloying elements when we consider sulfur, oxygen, carbon, and hydrogen. These data can be used to inform models of planetary accretion, composition, and evolution.
AB - We present the first observations of seismic waves propagating through the core of Mars. These observations, made using seismic data collected by the InSight geophysical mission, have allowed us to construct the first seismically constrained models for the elastic properties of Mars core. We observe core-Transiting seismic phase SKS from two farside seismic events detected on Mars and measure the travel times of SKS relative to mantle traversing body waves. SKS travels through the core as a compressional wave, providing information about bulk modulus and density. We perform probabilistic inversions using the core-sensitive relative travel times together with gross geophysical data and travel times from other, more proximal, seismic events to seek the equation of state parameters that best describe the liquid iron-Alloy core. Our inversions provide constraints on the velocities in Mars core and are used to develop the first seismically based estimates of its composition. We show that models informed by our SKS data favor a somewhat smaller (median core radius = 1,780 to 1,810 km) and denser (core density = 6.2 to 6.3 g/cm3) core compared to previous estimates, with a P-wave velocity of 4.9 to 5.0 km/s at the core mantle boundary, with the composition and structure of the mantle as a dominant source of uncertainty. We infer from our models that Mars core contains a median of 20 to 22 wt% light alloying elements when we consider sulfur, oxygen, carbon, and hydrogen. These data can be used to inform models of planetary accretion, composition, and evolution.
KW - Mars
KW - core evolution
KW - planetary structure
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U2 - 10.1073/PNAS.2217090120
DO - 10.1073/PNAS.2217090120
M3 - Article
C2 - 37094138
AN - SCOPUS:85153686970
SN - 0027-8424
VL - 120
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 - 118
M1 - e2217090120
ER -