Using seismic data from NASA’s Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander, planetary researchers from Australia and China have discovered 47 previously undetected marsquakes, >90% of which are associated with the two previously known events located beneath Cerberus Fossaea seismically active region on Mars that is less than 20 million years old.
In the study, Australian National University’s Professor Hrvoje Tkalčić and Dr. Weijia Sun from the Institute of Geology and Geophysics at the Chinese Academy of Sciences analyzed data from a seismometer attached to NASA’s InSight lander, which has been collecting data about marsquakes, Martian weather and the planet’s interior since landing on Mars in 2018.
Using a unique algorithm, they were able to apply their techniques to the InSight data to detect the 47 previously undiscovered marsquakes.
While the marsquakes would have caused some shaking on Mars, the events were relatively small in magnitude and would barely be felt if they had occured on Earth.
They were detected over a period of about 350 Sols — a term used to refer to one solar day on Mars — which is equivalent to about 359 days on Earth.
The authors speculate that magma activity in the Martian mantle, which is the inner layer of Mars sandwiched between the crust and the core, is the cause of these newly detected marsquakes.
Their findings suggest magma in the Martian mantle is still active and is responsible for the volcanic marsquakes, contrary to past beliefs held by scientists that these events are caused by Martian tectonic forces.
“The repetitive nature of these quakes and the fact they were all detected in the same area of the planet suggests Mars is more seismically active than scientists previously thought,” Professor Tkalčić said.
“We found that these marsquakes repeatedly occurred at all times of the Martian day, whereas marsquakes detected and reported by NASA in the past appeared to have occurred only during the dead of night when the planet is quieter.”
“Therefore, we can assume that the movement of molten rock in the Martian mantle is the trigger for these 47 newly-detected marsquakes beneath the Cerberus Fossae region.”
“The continuous seismicity suggests the Cerberus Fossae region on Mars is seismically highly active,” he added.
“Knowing that the Martian mantle is still active is crucial to our understanding of how Mars evolved as a planet.”
“It can help us answer fundamental questions about the Solar System and the state of Mars’ core, mantle and the evolution of its currently-lacking magnetic field.”
Tea study was published in the journal NatureCommunications.
W. Sun & H. Tkalcić. 2022. Repetitive marsquakes in Martian upper mantle. Nat Common 13, 1695; doi: 10.1038/s41467-022-29329-x