Following a powerful earthquake on Mars, planetary scientists noticed that its crust was thicker than Earth’s.
According to a researcher’s report in a paper awaiting publication in Geophysical Research Letters, the thickness of the crust is between 42 and 56 kilometers on average, which is about 70 percent thicker than the typical continental crust on Earth.
The measurement is based on data from NASA’s InSight lander, a stationary seismometer that has recorded waves flowing inside Mars for four Earth years, the report said.
Last May, the entire Red Planet was rocked by a magnitude 4.7 earthquake that lasted more than six hours.
“We were really lucky that we got this earthquake,” said seismologist Doyeon Kim of ETH Zurich.
Kim and colleagues confirmed the thickness of the crust across the planet with the help of InSight, which recorded seismic waves from earthquakes that hit the planet up to three times.
According to the team’s findings – in addition to the crust being thicker than Earth and the moon – it is also not uniform throughout Mars.
This discovery could explain a significant north-south elevation difference on the planet.
According to topological and gravity data from Mars orbiters, the northern hemisphere of the planet is significantly lower than the southern.
Researchers suspect that this may be due to the difference between the density of rocks in both regions of the planet.
However, following the discovery by Kim and colleagues, it appears that the crust is thinner in the northern hemisphere, so rocks in both hemispheres likely have the same average density.
Furthermore, in calculating the depth of the crust, the team also calculated that most of Mars’ interior heat probably comes from the crust.
“Most of this heat comes from radioactive elements like potassium, uranium, and thorium. An estimated 50 to 70 percent of those elements are likely in the crust rather than the underlying mantle,” the research said.
This revelation also supports the idea that volcanic activity can still be found in some parts of Mars, rejecting claims that the “Red Planet is dead”.