It vibrates on Mars: Hot rock vibrates

Below the Elysium plane on Mars is an area about 4,000 kilometers wide of hot rocks rising from the planet’s deep mantle. This is shown by a study by two American researchers that combined all available data on the Elysium plane. The so-called plume provides an explanation for the seismic activity in the region detected by the NASA probe “InSight”, scientists explain in the journal “nature astronomy,

“Mars was primarily volcanically and tectonically active for the first 1.5 billion years of its history,” explain Adrian Brockett and Jeffrey Andrews-Hanna of the University of Arizona. “But especially in Elysium Planitia, there has also been recent volcanic and seismic activity.” The “InSight” lander, which has been stationed at the Elysium Plain since 2018, has recorded several seismic tremors emanating from the geologically young Cerberus Fosse Graben system. , Just 53,000 years ago there was apparently still volcanic activity.

Because there is no plate tectonics on Mars, unlike Earth, “volcanic and tectonic activity on cold Mars is unpredictable,” say the two planetary researchers. In search of an explanation, Brockett and Andrews-Hannah constructed a detailed model of the region based on surface texture, elevation profiles and gravity anomalies measured by spacecraft orbiting the Red Planet.

The researchers made the best agreement with all available data under the assumption that there is a giant mantle plume beneath Elysium Planitia. This is what geologists mean by a region where hot rock flows from the planet’s deep mantle. When the rising rock meets the planet’s solid outer shell, it expands and the plume takes on a mushroom shape. Such mantle plumes are also known from Earth and are the cause of “hotspot volcanism”, which are not bound by continental plate boundaries.

heated to 285 degrees

Researchers say the head of the plume beneath the Elysium Plain is about 4,000 kilometers in diameter, and between 96 and 285 degrees hotter than the surrounding rock. According to the researchers, the center is located exactly under the Cerberus Fossae graben system and thus provides a natural explanation for recent volcanism in the region as well as for the earthquakes registered by “InSight”. (dpa)

However, the discovery of such a plume raises questions about the geological evolution of our neighboring planet. Because current global models of Mars only predict slow mixing of mantle rock by convection, not plume formation. “The evidence we found for an active, large mantle plume poses a challenge to our understanding of the thermal evolution and internal dynamics of Mars,” say Brockett and Andrews-Hanna.

to home page