Surprising New Evidence Shows Venus Has Active Volcanoes

Surprising new evidence shows that Venus has active volcanoes. Beneath the planet's thick and suffocating atmosphere, it has scorching hot temperatures, with most of the surface composed of and shaped by flows and surges from volcanic activity. Nonetheless, planetary geologists studying Venus in the past have failed to obtain hard evidence of active volcanic events on the planet.

Scientists recently got the best evidence so far. A team of scientists led by Anna Gülcher, an ETH Zürich, Switzerland geophysicist, published a study in the journal Nature Geoscience. The researchers employed simulations in determining the formation and growth of volcanic coronae. From these simulations, they concluded that the Venusian features are young, which means Venus is not volcanically extinct.

Coronae are a part of the abundant volcanic features found on the surface of Venus. Other features include vast volcanic plains, domes, and mountain shield volcanoes.

Laurent Montési, a University of Maryland geologist, says it was the first time they were able to identify specific structures to be active or dormant. Their study, he says, significantly changes our view of the planet from being mostly inactive to something with a churning interior, possibly feeding several active volcanoes.

It has been known how Venus' surface is relatively young in comparison to the other planets in the solar system, such as Mercury and Mars. Geologic mapping and analysis of Venus revealed how most of it had resurfaced around the past billion years or so.

Many things can occur in such a long time. The planet's interior may have cooled, and its crust possibly hardened so that it has become impenetrable to liquid magma below the surface. More and more evidence is being collected. However, that shows this is not presently the case.

As an example, sulfur dioxide has been found in the planet's atmosphere by the Pioneer Venus Orbiter from 1978 to 1986.  A study from 2015 also presented observations of bright, transient spots that could represent lava flows. And a study published last January 2020, which simulated olivine rates of weathering, also concluded that the Venusian lava flows are likely to be very young.

Researchers at first thought coronae were craters. However, upon closer analysis, they proved to be volcanic, created by the plumes of hot molten matter coming from the interior and pushing the planet's surface upward, forming a dome which collapses inward when the plume has cooled. The leaks going out to its sides form the corona ring.

The researchers modeled thermo-mechanical activity in Venus' interior and generated 3D, high-resolution simulations of the process of corona formation, changing plume sizes and temperatures, and the lithosphere's thickness.

Their results showed how corona variations represent various stages of geological development, suggesting that coronae are actively evolving, with an active planetary interior. The researchers say they have been able to identify 37 recently active coronae. These coronae are clustered in just a few areas, which suggests that some regions are more active compared to others. This information will be useful in optimally determining locations that orbital and landing Venus missions can select.