A wide range of geologic features, from individual volcanoes to vast lava plains, provide evidence of Venus’ volcanic past. Moreover, circumstantial evidence, such as transient bright spots in thermal emission and varying sulfur dioxide abundance in the atmosphere, indicates that Venus may still be experiencing volcanic activity. Determining the extent to which Venus is volcanically active would aid in understanding the planet’s interior and volatile element abundances and help explain how Earth’s near-twin in size and overall composition diverged so drastically in geologic and atmospheric evolution. Future spacecraft missions to Venus may be able to detect volcanic activity, but knowing how often eruptions might occur is important in planning this search.
Paul K. Byrne of Washington University in St. Louis and Siddharth Krishnamoorthy of NASA Jet Propulsion Laboratory used statistics to infer the frequency of eruptions on Venus. Using the Smithsonian Institution’s Global Volcanism Program database, they built a catalogue of eruptions that occurred on Earth from 1980 to 2021, including data for duration and intensity. They randomly chose 73.6% of these eruptions to account for Venus’ smaller size, and then counted the new and ongoing events in a random 60-day period, repeating this process for 100,000 trials. They found that as many as 120 new or ongoing eruptions may occur on Venus per Earth year. However, the researchers cautioned that their conclusions depend on the validity of the assumption that Earth’s volcanic activity can be scaled to Venus, which lacks the plate tectonic system that controls most volcanic activity on Earth.
These predictions will be tested in the coming decade when NASA’s VERITAS and ESA’s EnVision arrive at Venus with instruments to monitor the surface and atmosphere and detect geomorphological, chemical, and thermal changes associated with eruptions. If the estimates of Byrne and Krishnamoorthy prove correct, there should be abundant volcanic activity for these spacecraft to observe. READ MORE