Mars Quake Unveils Planet's Astonishingly Thick Crust, Surpassing Earth's
May 26, 2023
Scientists now have knowledge of the thickness of the crust on Martian due to the most powerful Marsquake ever recorded.
According to a forthcoming paper in Geophysical Research Letters, researchers have found that the crust has an average thickness ranging from 42 to 56 kilometers. This measurement indicates that amounts to an approximate increase of 70 percent in thickness compared to the typical crust found on continents of Earth.
Data from NASA's InSight lander, which is a stationary seismometer. Its captured waves reverberating through Mars' interior for four Earth years, served as the basis for the measurement. A magnitude 4.7 earthquake that shook the entire planet in May of last year lasted for over six hours. We were quite lucky to experience this earthquake, according to seismologist Doyeon Kim of ETH Zurich.
Seismic waves from the earthquake that three times encircled Mars were captured by InSight. This enabled Kim and his colleagues to determine the thickness of the planet's crust.
The researchers discovered that the Red Planet's crust is not just unevenly distributed but also thicker than that of the Earth and the moon. And that could account for a known elevation differential on Mars between north and south.
Analysis of topological and gravity data gathered by Mars orbiters has revealed a significant disparity between the northern and southern hemispheres of the planet. Scientists hypothesized that variations in density could be a contributing factor, suggesting that the rocks comprising the northern region of Mars may possess a different density compared to those in the southern region.
However, Kim and colleagues discovered that the crust in the northern hemisphere is actually thinner. This suggests that the rocks in both the northern and southern hemispheres likely have similar average densities. This important finding assists scientists in narrowing down the possible explanations for the initial existence of the disparity between the hemispheres.
The scientists determined that a significant portion of Mars' internal heat likely originates in the crust based on the depth of the crust. The majority of this heat is produced by radioactive substances like thorium, uranium and potassium. Computer simulations predict that between 50 and 70 percent of those components are likely in the crust rather than the mantle beneath. Contrary to long-held assumptions, this suggests that some regions of Mars still experience volcanic activity (SN: 11/3/22).
