Mystery of volcanic activity migration on Mars explained

Washington, Dec 16 : A geophysicist has provided a possible explanation for the migration of volcanic activity on Mars.

According to CU-Boulder Geophysicist Shijie Zhong, the shell-like outer plate of the Red Planet might be moving, driven by a powerful single plume of hot material affecting an area of thickened crust called the Crustal Dichotomy, thus explaining the migration of volcanic activity in the Tharsis Rise region of Mars.

After a first glance at the Martian surface, one may quickly notice two striking global-scale features.

The first is the three-mile elevation difference between the northern lowlands and southern highlands, known as the Crustal Dichotomy, which got the name because the highlands and lowlands are underlain by thick and thin crust, respectively.

The second feature is the vast area of high elevation with numerous volcanoes near the equator covering a quarter of the Martian surface, known as the Tharsis Rise.

Mars appears to have a single plate that encapsulates the entire planet like the shell of an egg.

But Shijie Zhong, associate professor of physics at the University of Colorado at Boulder, thinks this shell-like plate might be moving, driven by a powerful, single plume of hot material affecting the area of the thickened crust of the Crustal Dichotomy.

"This would explain the migration of volcanic activity in the Tharsis Rise region of the formation of Tharsis," he said.

Using three-dimensional numerical models to simulate the slow churning of Mars' interior in response to the cooling of the planet, Zhong shows that a single plume of hot material rising through the planet's interior led to the earliest volcanism in the highlands region of the Crustal Dichotomy, simultaneously triggering rotation of the outer shell.

As the shell moved southward over the stationary plume, like a sheet of cardboard over a candle, it shifted the location of the volcanism and created the Tharsis Rise. (ANI)

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