Enormous Volcanoes on Venus May Still Be Active

Researchers have identified 37 recently active volcanic structures on Venus, according to a study. The discovery provides some of the best evidence to date that the planet is still volcanically active, said the authors of the paper published in the journal Nature Geoscience.

There is growing consensus among scientists that Venus is volcanically active today, although there is no concrete evidence of a recent eruption. Radar images show that there are over 1,600 major volcanic structures or volcanoes on Venus, more than any other planet in the solar system. Most of these are thought to be long dead, however, data is very limited so it's possible that some are still active.

Furthermore, the planet features lava plains that appear to be relatively young, geologically speaking. And scientists have also observed unusual changes in the amount of sulfur dioxide in the atmosphere—a process which could indicate that volcanism has taken place.

In the latest study, a team from the University of Maryland (UMD) and the Institute of Geophysics at ETH Zurich, Switzerland examined 100 vast volcanic ring-like structures on Venus known as "coronae" that form when plumes of hot material rise up from deep inside the planet and emerge through the outer crust, much like how the volcanic Hawaiian Islands form on Earth.

Even the smallest of the structures that the team looked at measured more than 185 miles in diameter—almost equivalent to the distance between New York and Boston. The largest measures more than 1,200 miles across.

There has been much debate over how active the interior of Venus truly is. Previously, scientists have thought that the coronae on Venus are evidence only of ancient volcanic activity and that the planet has cooled enough to reduce geological activity in the interior and harden the crust sufficiently so that any plumes of material would not be able to puncture through.

However, the authors of the latest study found that around a third of the coronae they looked at displayed the characteristic signatures indicating the presence of an active plume. This contradicts the view that the planet's interior is mostly inactive.

"This is clear evidence that the interior of Venus is currently churning. In all these case, the plume activity is expected to generate new magma that should make it to the surface," Laurent Montési, a professor of geology at UMD and co-author of the paper, told Newsweek.

"These 37 active coronae are places where there is in all likelihood very recent, and perhaps current volcanic activity. This is not volcanism in general but at these specific places. It is also interesting how these locations are clustered in a few regions on the planet, but we don't know yet why that is," he said.

The scientists made their findings using a highly sophisticated numerical model that is able to realistically simulate the processes taking place in the interior of the planet. This enabled them to create high resolution, 3D simulations of how the coronae formed.

Maat Mons, volcano
The volcano Maat Mons is displayed in this computer generated three-dimensional perspective of the surface of Venus. NASA/JPL

With the help of this technique, the researchers identified features—namely the presence of trenches surrounding the coronae—that only exist when the underlying plume is active.

"That feature goes away in a few millions of years. So, we infer that the coronae that feature these trenches have been active during that time, which is essentially today at geological time scales," Montési said.

"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," Montési said in a statement.

According to the researchers, the latest results could have significant implications for future missions to Venus, such a Europe's EnVision, which is scheduled to launch in 2032.

"We now have specific high-interest targets for finding recent or current volcanism," Montési told Newsweek. "The coronae we identify as recently active would be good places to hunt for evidence of current volcanic activity, as well as fault motions. These missions could have high-resolution radar and topography instruments. It may be possible to document changes in the surface over the duration of the mission."

"For these activities to be successful it is best to know in advance where to look for, so that we can focus specifically on these regions. Our work can be use to help selecting the regions of highest interest," he said.