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Updated: Aug 1, 2025
08:02
Reservoir Condition Pore-scale Imaging of Multiple Fluid Phases Using X-ray Microtomography
Published on: February 25, 2015
12.6K
First observations of core-transiting seismic phases on Mars.
Jessica C E Irving1, Vedran Lekić2, Cecilia Durán3
1School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, United Kingdom.
Summary
Seismic waves from InSight reveal Mars
Area of Science:
- Planetary Science
- Seismology
- Geophysics
Background:
- Understanding the internal structure and composition of Mars is crucial for comprehending planetary formation and evolution.
- Previous models of Mars' core were based on indirect geophysical data, lacking direct seismic constraints.
Purpose of the Study:
- To present the first seismic observations of waves passing through Mars' core.
- To develop the first seismically constrained models for the elastic properties and composition of Mars' core.
Main Methods:
- Analysis of seismic data from the InSight mission, specifically observing core-transiting seismic phase SKS from farside seismic events.
- Measurement of SKS travel times relative to mantle-traversing body waves.
- Probabilistic inversions using SKS travel times, geophysical data, and proximal seismic event data to determine core equation of state parameters.
Main Results:
- First direct seismic evidence of SKS waves traversing the Martian core.
- Seismically constrained models indicate a smaller (median radius 1,780–1,810 km) and denser (6.2–6.3 g/cm³) core than previously estimated.
- Estimated P-wave velocity at the core-mantle boundary is 4.9–5.0 km/s.
- Inferred Martian core composition includes 20–22 wt% light alloying elements (sulfur, oxygen, carbon, hydrogen).
Conclusions:
- The study provides the first seismic constraints on the elastic properties and composition of Mars' core.
- The findings suggest a denser and potentially smaller core than previously modeled, with significant light element content.
- These results will inform future models of planetary accretion, composition, and evolution, particularly for terrestrial planets.
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