The 2021 marsquake suggests the Solar System’s largest canyon may still be active

Valles Marineris, the giant canyon that cuts across Mars’s equatorial region, may still be tectonically active billions of years after it formed.

A new scientific study supports this conclusion, drawing on seismic data collected by NASA’s InSight lander. Researchers say a marsquake recorded on August 25, 2021, may have been caused by the movement of faults beneath the planet’s surface.

The seismic signal came from the opposite side of Mars from where the lander was located. A research team led by Imperial College London examined the waves’ amplitude and direction to determine where the quake may have originated.

The analysis, published in the journal Nature Communications, links the event to tectonic activity in Valles Marineris. The region therefore joins other areas on Mars where InSight has recorded possible signs of active faults.

The canyon stretches about 3,900 kilometers, is up to 600 kilometers wide, and in some places is more than nine kilometers deep. Compared with the Grand Canyon in the United States, Valles Marineris is about nine times longer, 20 times wider, and five times deeper.

However, identifying the source of quakes in this region is challenging. On Mars, seismic waves can be generated by tectonic movements, meteoroid impacts, landslides, or other geological processes.

To determine what caused the quake, the researchers examined how the waves traveled through the planet. The results suggest it may have been caused by the fracturing and displacement of a tectonic structure in Valles Marineris.

According to the analysis, the movement occurred at a depth of 20 to 40 kilometers. Two blocks of rock may have slid horizontally past one another.

This movement indicates that the Martian crust may still be deforming today, although Mars does not have the level of tectonic activity seen on Earth.

The discovery helps clarify the planet’s internal structure and the processes that alter its surface. Data from the InSight mission allow scientists to reconstruct Mars’s geological history and identify regions that may remain active billions of years after forming.