Martian Seismic Data Suggests Potential Liquid Water Reserves at Depth

Martian Seismic Data Suggests Potential Liquid Water Reserves at Depth
by Simon Mansfield
Sydney, Australia (SPX) May 12, 2025

Liquid water, a critical component for the habitability of Mars, may still be present beneath its surface, according to a recent study conducted by an international team of geophysicists and geologists. The research, led by Dr. Weijia Sun from the Institute of Geology and Geophysics, Chinese Academy of Sciences, alongside Dr. Hrvoje Tkalcic of The Australian National University, Dr. Marco G. Malusa of the University of Milano-Bicocca, and Dr. Yongxin Pan of the Institute of Geology and Geophysics, Chinese Academy of Sciences, explored the fine structure of the Martian crust as a potential breakthrough in understanding the planet's water history.

Liquid water once flowed abundantly on Mars during the Noachian and Hesperian periods, up to about 3 billion years ago. However, it disappeared from the surface during the colder, drier Amazonian period. Whether liquid water remains within Mars' crust today, and at what depth, has long been a scientific enigma. As Dr. Hrvoje Tkalcic noted, "The water involves profound questions about life and humanity's future on the Red Planet."

The research team analyzed seismic waveforms from NASA's InSight mission, specifically focusing on the two largest meteorite impacts (S1000a and S1094b) and the most significant marsquake (S1222a) ever recorded. Their seismic inversion analysis uncovered a notable low shear-wave velocity anomaly at depths between 5.4 to 8 kilometers, indicating the potential presence of liquid water at the base of the upper Martian crust.

The team estimates that this hidden water could amount to a Global Equivalent Layer (GEL) of approximately 520 to 780 meters, assuming the pores in this region are fully saturated. However, this estimate is derived solely from the seismic profile beneath the InSight lander and does not account for the potentially more complex lateral structural variations that may exist across the Martian crust. The researchers also caution that this estimate does not include any primordial liquid water that may still be present.

This discovery provides critical insights into the Martian water cycle, the planet's geological evolution, and its potential habitability. Future missions equipped with advanced seismometers could offer further evidence to confirm the extent and distribution of this possible subsurface water.

Research Report:Seismic evidence of liquid water at the base of Mars' upper crust