Seismic clues from Marsquakes suggest liquid water and potential for life beneath the surface
A recent study led by scientists Ikuo Katayama from Hiroshima University and Yuya Akamatsu from the Research Institute for Marine Geodynamics has revealed groundbreaking interpretations of Martian seismic data. Utilizing the advanced capabilities of NASA's InSight lander, Katayama and Akamatsu suggest that the presence of liquid water might still exist beneath the Martian surface, creating possibilities for microbial life.
Key Findings:
- The analysis of seismic data obtained from the SEIS (Seismic Experiment for Interior Structure) has indicated boundaries in the Martian subsurface at depths of approximately 10 km and 20 km.
- Katayama asserts that "if liquid water exists on Mars, the presence of microbial activity" is indeed possible.
- The data indicates a transition from dry, cracked rock to water-saturated rock, supporting the hypothesis of liquid water existing in Martian geology today.
Understanding Marsquakes and the InSight Mission
The InSight lander, which landed on Mars in 2018, represents a crucial advancement in Martian exploration. The SEIS instrument deployed by InSight is unique as it can utilize robotic arm technology to position the seismic tool directly onto the Martian surface, capturing seismic waves generated by natural phenomena like Marsquakes and meteorite impacts.
Upon these seismic events, the SEIS detects energy emitted as P-waves, S-waves, and surface waves, allowing scientists to map and analyze the structure and composition of the planet.
Seismic Wave Analysis and Implications
Utilization of seismic data allows scientists to measure both P-waves and S-waves' properties. Notably:
- S-waves cannot propagate through liquid media; therefore, their absence can indicate water-bearing zones.
- P-waves, being able to traverse various materials, provide insights into the density and composition of the subsurface.
Crucially, discrepancies in seismic velocity measurements point towards distinct boundaries at depths of 10 km and 20 km, previously attributed to changes in chemical composition or porosity of the Martian crust.
Liquid Water: A Possible Reality
Through their research, Katayama and Akamatsu challenge the existing interpretations by suggesting these boundaries reflect a transition from dry, fractured rock to rock saturated with water. To validate their hypothesis, they conducted laboratory experiments on rock samples that mirror typical Martian geology.
In these experiments, they used a piezoelectric transducer to effectively measure the seismic wave velocities of dry, wet, and frozen samples of diabase rock, akin to what is found on Mars. The results demonstrated significant differences supporting their argument of water-filled cracks under the Martian surface.
Conclusions and Future Research
The implications of this research are significant, suggesting that liquid water may exist beneath the surface of Mars, lending credence to theories of potential microbial life. Katayama notes, "Many studies suggest the presence of water on ancient Mars billions of years ago, but our model indicates the presence of liquid water on present-day Mars."
Such findings encourage future explorations aimed at substantiating these discoveries and informing scientific discussions about Martian habitability.
For more information, visit: Surface waves help map the interior of Mars.
Literature Cited
[1] Katayama, I., Akamatsu, Y., Seismic discontinuity in the Martian crust possibly caused by water-filled cracks, *Geology* (2024). DOI: 10.1130/G52369.1
[2] NASA InSight Mission, NASA.
[3] Seismic Data, Phys.org.
[4] Geological Society of America, GSA.
