A quake on Mars showed its crust is thicker than Earth’s

Planetary scientists now know the way thick the Martian crust is, due to the strongest Marsquake ever noticed.

On common, the crust is between 42 and 56 kilometers thick, researchers report in a paper to seem in Geophysical Analysis Letters. That’s roughly 70 % thicker than the common continental crust on Earth.

The measurement was primarily based on information from NASA’s InSight lander, a stationary seismometer that recorded waves rippling by means of Mars’ inside for 4 Earth years. Final Could, all the planet shook with a magnitude 4.7 quake that lasted more than six hours (SN: 5/13/22). “We had been actually lucky that we received this quake,” says seismologist Doyeon Kim of ETH Zurich.

InSight recorded seismic waves from the quake that circled Mars as much as thrice. That allow Kim and colleagues infer the crust thickness over the entire planet.

Not solely is the crust thicker than that of the Earth and the moon, however it’s additionally inconsistent throughout the Crimson Planet, the crew discovered. And which may clarify a recognized north-south elevation distinction on Mars.

Topological and gravity information from Mars orbiters have proven that the planet’s northern hemisphere is considerably decrease than the southern one. Researchers had suspected that density would possibly play a component: Maybe the rocks that make up northern Mars have a special density than these of southern Mars.

However the crust is thinner within the northern hemisphere, Kim and colleagues discovered, so the rocks in each hemispheres in all probability have the identical common densities. That discovering helps scientists slender down the reasons for why the distinction exists within the first place.

Figuring out the crust’s depth, the crew additionally calculated that a lot of Mars’ inside warmth in all probability originates within the crust. Most of this warmth comes from radioactive components reminiscent of potassium, uranium and thorium. An estimated 50 to 70 % of these components are in all probability within the crust relatively than the underlying mantle, pc simulations recommend. That helps the concept that elements of Mars still have volcanic activity, opposite to a long-held perception that the Crimson Planet is useless (SN: 11/3/22).  

Lisa Grossman

Lisa Grossman is the astronomy author. She has a level in astronomy from Cornell College and a graduate certificates in science writing from College of California, Santa Cruz. She lives close to Boston.


Leave a Reply

Your email address will not be published. Required fields are marked *