Mars' Valles Marineris canyon is still tectonically active, study finds

Seismic data from NASA's InSight lander points to deep fault slip beneath the solar system's largest canyon

By LineZotpaper AI staff

Published23 October 2026

Read Time3 min

A marsquake recorded by NASA's InSight lander in August 2021 was caused by rocks slipping along fault lines deep beneath Valles Marineris, according to a new study. The finding indicates that the solar system's largest canyon remains tectonically active, despite Mars having no tectonic plates.

New analysis of a marsquake detected by NASA's InSight lander shows that Valles Marineris, the largest canyon in the solar system, is still being shaped by active faulting, researchers report in Nature Communications.

The quake, designated S0976a, was recorded on August 25, 2021, and was the only marsquake InSight detected in the planet's western hemisphere. It originated on the opposite side of Mars from the lander.

Led by Jung-Hun Song of Imperial College London, with researchers from Columbia University and the University of Illinois Urbana-Champaign, the team tested whether the event was caused by a meteoroid impact or a landslide, but models could not reproduce the observed seismic waves. Satellite images from NASA's Mars Reconnaissance Orbiter showed no fresh crater or landslide. The best match was a strike-slip marsquake, in which blocks of crust slide horizontally past each other along a steep fault about 20 to 40 kilometres beneath the valley.

"What makes the result compelling is that several completely different types of evidence point in the same direction," Song said. "The seismic waves tell us that there was a sideways sliding motion on a fault well below the surface, while the geology seen from orbit shows a region crossed by long-lived fault systems."

Valles Marineris stretches about 3,900 kilometres long, up to 600 kilometres wide and more than 9 kilometres deep, dwarfing Earth's Yarlung Tsangpo Grand Canyon. The canyon is thought to have formed from rift faults created by tensional forces tied to the volcanic activity of the Tharsis Bulge between 4.1 and 3.0 billion years ago.

Mars has a single crustal plate, making it a "stagnant lid" planet, and was long assumed to be geologically dead. InSight previously detected active faulting at Cerberus Fossae and southern Elysium Planitia, and the new results add Valles Marineris to that list.

"From a single marsquake, we can learn both about the center of the planet and about an active fault beneath one of its most remarkable landscapes," said Doyeon Kim, a senior author of the study. The mission ended four years ago after dust built up on its solar panels, but its data continues to yield discoveries.

Analysis

Why This Matters

The discovery overturns the long-held assumption that Mars is geologically dead and shows its crust can still rupture under stress.
It suggests comparable active faulting may exist on other planetary bodies thought to be inactive, widening the targets for future seismic study.
It demonstrates that data from the ended InSight mission continue to yield new findings about the Red Planet's interior and surface.

Background

Mars is a "stagnant lid" planet: its crust is a single plate rather than moving plates like Earth's. For decades, its volcanoes and canyons were seen as relics of an ancient active period. The InSight lander, which arrived in 2018, began recording marsquakes and other signs that the planet is still active. Valles Marineris is a vast rift system believed to have formed billions of years ago amid the volcanic activity that created the Tharsis Bulge.

What to Watch

Whether future analysis of InSight's data archive or new missions with seismometers detect further slip events beneath Valles Marineris.
Whether seismic observations from other "stagnant lid" bodies, such as the Moon or Venus, reveal similar deep fault activity.
Whether continued imaging of the canyon by orbiters turns up surface changes matching the study's geological model.

Sources

The Largest Canyon in the Solar System is Still Tectonically Active · Universe Today

Checked

12 claims in this story checked against 1 source: 11 supported.

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SupportedValles Marineris is still tectonically active, the headline says.Universe Today: “The Largest Canyon in the Solar System is Still Tectonically Active.”
SupportedSeismic data points to deep fault slip beneath the solar system’s largest canyon.Universe Today: “According to InSight's data, the event (S0976a) was caused by rocks slipping along fault lines deep within the crust.”
SupportedThe quake was caused by rocks slipping along fault lines deep beneath Valles Marineris.Universe Today: “According to InSight's data, the event (S0976a) was caused by rocks slipping along fault lines deep within the crust.”
Partly supportedThe study shows Valles Marineris is still being shaped by active faulting.Universe Today: “The best fit was a strike-slip marsquake, in which blocks of crust move horizontally past each other along a steep fault about 20 to 40 km (12 to 24 mi) beneath the valley.”
SupportedSong said, “What makes the result compelling is that several completely different types of evidence point in the same direction. The seismic waves tell us that there was a sideways sliding motion on a fault well below the surface, while the geology seen from orbit shows a region crossed by long-lived fault systems.”Universe Today: “What makes the result compelling is that several completely different types of evidence point in the same direction. The seismic waves tell us that there was a sideways sliding motion on a fault well below the surface, while the geology seen from orbit shows a region crossed by long-lived fault systems.”
SupportedKim said, “From a single marsquake, we can learn both about the center of the planet and about an active fault beneath one of its most remarkable landscapes.”Universe Today: “From a single marsquake, we can learn both about the center of the planet and about an active fault beneath one of its most remarkable landscapes.”
SupportedS0976a was recorded on August 25, 2021.Universe Today: “For their study, the team analyzed the S0976a seismic event that was recorded by InSight on August 25th, 2021.”
SupportedS0976a was the only marsquake InSight detected in Mars’s western hemisphere.Universe Today: “This was the only marsquake detected in Mars's western hemisphere, and it originated on the opposite side of the planet.”
SupportedThe team tested impact and landslide explanations, but its models could not reproduce the observed seismic waves.Universe Today: “The team built models to test these explanations, but they couldn't reproduce the observed seismic waves.”
SupportedThe best match was a strike-slip quake along a steep fault about 20 to 40 kilometres beneath the valley.Universe Today: “The best fit was a strike-slip marsquake, in which blocks of crust move horizontally past each other along a steep fault about 20 to 40 km (12 to 24 mi) beneath the valley.”
SupportedValles Marineris is about 3,900 kilometres long, up to 600 kilometres wide and more than 9 kilometres deep.Universe Today: “The vast canyon system spans 3,900 km (2,423 mi) long, up to 600 km (373 mi) wide, and more than 9 km (5.5 mi) deep.”
SupportedThe mission ended four years ago because dust built up on its solar panels.Universe Today: “Lastly, the results show that four years after the mission ended because of dust buildup on its solar panels, InSight continues to provide valuable insight into the Red Planet.”