The Heterogeneity of the Martian Mantle Is Being Questioned

The structure and dynamics of the Martian mantle are still poorly understood. Recently, a team of researchers proposed that Mars’s mantle contains a large number of heterogeneities inherited from the planet’s accretion period. However, a new study led by Ludovic Margerin, a CNRS Terre & Univers researcher at IRAP, calls these findings into question. According to this study, the analysis of InSight seismic data—which concludes that the Martian mantle is highly heterogeneous—contains observational and theoretical flaws.

To reanalyze the data, the researcher developed a method for measuring arrival times and the signal-to-noise ratio tailored to the P-waves detected by InSight. He also critically reexamined the possibility of explaining the observations in terms of multiple scattering through a heterogeneous medium.

The study’s results show that it is the decrease in the signal-to-noise ratio that causes apparent anomalies in P-wave propagation, rather than a multipath effect through a heterogeneous mantle. Furthermore, the study reveals that waves sampling the surface layer of Mars are subject to the same detection biases. Much remains to be learned about the heterogeneity of the Martian mantle. The exceptional data provided by InSight could make this possible.

Further Resource

• Scientific paper : Is the Deep Martian Mantle Heterogeneous? A Reappraisal of Seismological Evidences. L. Margerin, https://doi.org/10.1029/2025GL120875

IRAP Contact

• Ludovic Margerin, ludovic.margerin@utoulouse.fr