A Quake on Mars Showed Its Crust is Thicker Than Earth's

'Planetary scientists now know how thick the Martian crust is,' reports ScienceNews, 'thanks to the strongest Marsquake ever observed.'
On average, the crust is between 42 and 56 kilometers thick [26 to 34 miles], researchers report in a paper to appear in Geophysical Research Letters. That's roughly 70 percent thicker than the average continental crust on Earth.

The measurement was based on data from NASA's InSight lander, a stationary seismometer that recorded waves rippling through Mars' interior for four Earth years. Last May, the entire planet shook with a magnitude 4.7 quake that lasted more than six hours. 'We were really fortunate that we got this quake,' says seismologist Doyeon Kim of ETH Zurich.

InSight recorded seismic waves from the quake that circled Mars up to three times. That let Kim and colleagues infer the crust thickness over the whole planet. Not only is the crust thicker than that of the Earth and the moon, but it's also inconsistent across the Red Planet, the team found. And that might explain a known north-south elevation difference on Mars.

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