Detecting active volcanoes on Venus is a long-standing goal in planetary research. Venus is covered in sulfuric acid clouds and lava plains which probably originate from volcanic activity, but how many eruptions the planet experiences is unknown. Observing eruptions could help us discover the interior composition of the planet, determine its level of geologic activity, and understand its climate history – especially why it developed so differently from Earth. Upcoming missions to Venus position the search for volcanic activity as a key goal, but could we actually see volcanic eruptions if they occur?
Our study sought to answer part of this question by simulating plumes from volcanic eruptions in a planetary climate model and measuring how long they took to disperse. We selected a subset of gases associated with volcanic eruptions (water vapor, hydrogen chloride, carbon monoxide, and carbonyl sulfide) that can be observed on the Venus nightside. We then chose a few locations on the globe and created local enhancements of these gases for about an Earth day, approximating the “umbrella” phase of explosive volcanic eruptions on Earth, when the erupted material spreads out to its maximum extent. We observed how the gases spread out and how long it took for them to fade into the background.
Simulation of a volcanic plume umbrella dispersing in the Venus atmosphere. The trace gases simulated are water vapor, hydrogen chloride, carbon monoxide, and carbonyl sulfide. Simulation performed with the Venus Planetary Climate Model.
Venus has low wind speeds near the surface, but the wind increases steadily with altitude until it reaches over 100 m/s at the cloud tops. This means that plumes higher in the atmosphere dispersed much more quickly. In our simulations, the best-case scenario was plumes at 8-10 km near the equator. It took up to 100 hours for a large “umbrella” with a 50% increase in water vapor compared to the background level to completely disappear. On the other hand, plumes at 35 km, an altitude that is easier for instruments to observe, lasted less than 48 hours.
In reality, how long a volcanic plume is visible will depend on how long the eruption continues and how much material it injects into the atmosphere. We tested a range of eruption times and strengths. Only the very largest persisted for multiple days. In most cases, the time window for detecting a plume from a single eruption will be much less.
We found that, overall, near-surface equatorial regions offer the best prospects for detecting plumes because wind speeds are lowest there. An additional factor is that smaller, non-explosive eruptions would not reach high altitudes, but could potentially continue much longer. A volcanic vent that smokes for weeks may be more detectable than a Krakatoa-style eruption even though it is less powerful and the near-surface atmosphere is more difficult to observe.
Maureen Cohen, James Holmes, Joanna Egan, Stephen Lewis, and Manish R. Patel. “How long could volcanic plumes persist in the Venus atmosphere?” Planetary Research, 1(2), 316, 2026. https://doi.org/10.53480/1cyc-mm09
