Giant Canyon on Mars Is Still Tectonically Active, Study of a 2021 Marsquake Finds

Mars is often described as a dead world, its great landscapes frozen billions of years ago. A new analysis of one marsquake suggests the largest canyon in the solar system did not get the message.

Researchers at Imperial College London and Columbia University report that Valles Marineris is still tectonically active, according to Phys.org. The work appeared in Nature Communications, and Imperial College London published its announcement on 15 October.

What did the marsquake show?

The quake, catalogued as S0976a, was recorded by NASA's InSight lander on 25 August 2021. It was the only InSight-detected marsquake that could be located in the planet's western hemisphere, Imperial says.

The team, led by Jung-Hun Song with Folarin Kolawole and Doyeon Kim, studied the amplitudes and directions of the seismic waves to work out how the rock moved. The best fit was a strike-slip event, where blocks of crust slide sideways past each other along a steep fault. The rupture lay roughly 20 to 40 kilometres below western Valles Marineris.

Could it have been something else?

The researchers tested alternatives, including meteoroid impacts, landslides and other mass movements. None reproduced the observed waves. Satellite images taken after the event showed no fresh crater and no large new landslide, Phys.org reports.