The use of more refined numerical models of thermo-mechanical processes beneath the surface of the planet Venus has led a joint University of Maryland (in the US) and the Zurich Federal Institute of Technology (in Switzerland) research team to propose that there could be 37 active volcanoes on the second planet of our solar system. (Thermo-mechanics deals with the effects of heat on materials, in this case rocks.) Their findings were published in the journal Nature Geoscience on Monday.
The surface of Venus is dotted with ring-like structures known as coronae (singular: corona). These are clearly the results of molten rock rising from the planet’s mantle, through its crust, to its surface – like volcanoes on Earth. It has also been known for a while now that the surface of Venus is younger than the surfaces of Mars and Mercury.
However, it has been assumed that the coronae are all extinct, because it was also thought that Venus’ interior had cooled sufficiently to harden the crust and slow activity in the mantle. So molten rock – called magma on Earth – would no longer be able to break through to the surface.
The improved models allowed the researchers to develop high-resolution three-dimensional simulations of the formation of coronae. This in turn allowed them to identify features that would be found only in recently active coronae.
“The improved degree of realism in these models over previous studies makes it possible to identify several stages in corona evolution and define diagnostic geological features present only at currently active coronae,” explained paper co-author and University of Maryland geology Professor Laurent Montési. “We are able to tell that at least 37 coronae have been very recently active.”
The coronae identified as active are grouped in clusters in a small number of locations. This suggests which parts of Venus’ interior are most active and could help identify target areas for future space probes to Earth’s infamously hostile neighbouring world.
“This is the first time we are able to point to specific structures and say ‘Look, this is not an ancient volcano but one that is active today, dormant perhaps, but not dead’,” he highlighted. “This study significantly changes the view of Venus from a mostly inactive planet to one whose interior is still churning and can feed many active volcanoes.”
Previously, current volcanic activity was known on only four worlds in the Solar System. These are Earth itself, Io (a moon of Jupiter), Enceladus (a moon of Saturn) and Triton (a moon of Neptune).