(ORDO NEWS) — Scientists may have just identified the culprit behind signs of recent active volcanism on Mars.
Beneath a wide plain called Elysium Planitia, a colossal convection plume 4,000 kilometers (roughly 2,500 miles) wide in the Martian mantle can lift molten magma as far as the surface. This could explain the numerous evidence pointing to Mars of volcanic origin.
“Our results indicate that the interior of Mars is geodynamic ally active today,” write planetary geophysicists Adrian Broke and Jeffrey Andrews-Hanna of the University from Arizona, “and imply that volcanism was caused by mantle plumes from the formation of the Hesperian volcanic provinces, and Tarshish is the past to the present Elysium Plain.”
Mars has shown very strong indications that it is geologically dead. , inside and outside. Its relatively old surface, which appears to be free of recent volcanic fires and tectonic movements, as well as the absence of a global magnetic field, suggests that all the way down to the core there is nothing but solid, immobile rock.
Recent observations have revealed significant gaps in the idea of a completely dead Mars. Recently, about half a billion years ago, a meteorite from Mars fell to Earth, which showed signs of mantle convection , for example.
Satellite photographs then revealed traces of 50,000-year-old volcanic surface deposits in a fissure system called Cerberus Fossae.
And then Mars InSight, a lander that has been observing the interior of Mars since November 2018, detected significant ongoing seismic activity consistent with volcanism.
There were several other strange sightings as well. For example, the local gravitational field of Elysium Planitia is unusually strong, consistent with some kind of underground activity.
So Broke and Andres Hanna collected topographic, gravimetric, geological and seismic data and set about finding a suitable model.
According to their analysis, the mantle plume fits the bill. This is an upwelling of hot internal material that pushes against the planet’s core-mantle interface, pushing magma upward and forming crustal hotspots and surface volcanism.
To match observed data, including epicenters of seismic activity as detected by InSight, the plume would be at least 3,500 kilometers in diameter and be 95 to 285 degrees Kelvin warmer than its surroundings. This is 95 to 285 degrees Celsius, or 171 to 513 degrees Fahrenheit.
This is very similar to the mantle plumes on Earth that led to the prehistoric volcanic activity responsible for the extensive surface sculpture – the Deccan traps and North Atlantic volcanic eruptions. provinces.
“Although Mars is smaller than Earth, similarly large plumes are expected to form given the lower gravity and higher viscosity of the Martian mantle,” the researchers write in their paper.
“The most suitable center of the plume head, based solely on gravity and topography data, is precisely located at the center of the Cerberus pits, where both recent volcanism and most quakes have been detected.”
According to the researchers, this means that Mars will become the third planet in the solar system with mantle plume activity, joining Earth and Venus.
This result means quite interesting things for Mars. Maybe not surface volcanoes spewing lava everywhere, but internal heating that could keep lakes below the Martian surface from freezing.
This has implications for the search for Martian life – microbes that may be hidden in such lakes lead their quiet lives away from human detection.
“The constant activity of the plume demonstrates that Mars today is not only seismically and volcanically active. , but also has a geodynamically active interior,” write Broke and Andrews-Hanna.
“The plume under the Elysium Plain also indicates that surface volcanic flows and seismic activity are not isolated events, but are part of a long-lived, actively maintained regional system that is important for the longevity and astrobiological potential of underground habitable environments.”
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