On Venus, our sister planet, eruptions and lava flows can occur. In the study, scientists determined that Venusian volcanoes can make themselves felt even several times a year.
Venus, although similar to Earth in size and mass, differs from the Blue Planet in that it does not have tectonic plates. Meanwhile, on our planet, it is their movement that drives volcanic activity.
New research on this topic has been published in the latest issue of the scientific journal “Science”. Their author – Professor Robert Herrick of the Geophysical Institute of the University of Alaska in Fairbanks – reported that for eight months in 1991 one of the craters of a huge volcano on Venus changed its shape and increased significantly. On Earth, such changes are also possible, but they are clearly related to volcanic activity – whether it occurs through an eruption or through the movement of magma under the crater.
Only now it is easy to read the data
Herrick came to this conclusion after examining images taken years ago by the Magellan space probe. Until recently, comparing digital images to find new lava flows took too much time.
‘In fact, it’s only in the last decade that Magellan’s data has become available in full resolution and easy to analyze,’ said Herrick.
He added that in his analyzes he focused on the area where the two largest volcanoes on Venus are located – Ozza and Maat Mons.
“They are comparable in volume to Earth’s largest volcanoes, but they have a lower slope, which makes them more spread out,” Herrick said. In his work, he looked particularly closely at Maat Mons, which has a flared vent, indicating volcanic activity. He said the volcano looked different in the mid-February 1991 image than it did in October 1991. The researcher noticed a significant change in the vent on the north side of the shield volcano, which is part of Maat Mons.
Its crater has grown from a circular formation covering about 2.5 square kilometers to an irregular shape of slightly less than 4 square kilometers.
Photographs show that over the months the walls of the hole became shorter and the hole became almost filled to the brim. Studies suggest that a lava lake had formed in the hole in eight months, but it is not known whether its contents were liquid or already cooled and solidified.
Objectives for the next missions
As Herrick added, the surface of Venus is relatively young geologically, especially compared to all other rocky objects besides Earth and Jupiter’s moon Io.
“We estimate that Venus may experience from several large eruptions a year to one such eruption every few, dozen or so years” – he said. In his opinion, these phenomena contrast with what is known about volcanism at these objects.
“Io is so active that we’ve been able to image many ongoing eruptions every time we’ve watched it,” he said.
Herrick and his team’s research classifies Venus as one of the few planets in our solar system that is still volcanically active.
– We can now say that Venus is still volcanically active in the sense that there are at least a few eruptions per year. We can expect to see new volcanic flows in upcoming Venusian missions, he concluded.
Main photo source: NASA/JPL