ACTIVE VOLCANISM WHERE YOU LEAST EXPECT IT!

Volcanism is a fundamental geologic process that has affected every solid body in the solar system and, presumably, in other solar systems as well. As we explore other worlds, we come across signs of active and recently active volcanism, some in unexpected places. Volcanism in extraterrestrial worlds can be much different from the examples we see on Earth, but often the similarities are also striking. Understanding the eruption mechanisms on other planets is important for better constraining how eruptions behave on Earth under present and past conditions. Prior to the Voyager 1 and 2 spacecraft observations during the late 1970s and early 1980s, the Earth was the only planet known to have active volcanism. When Voyager 1 found active volcanism on Jupiter's moon Io, our understanding of active volcanism, and what causes it, dramatically changed. Voyager went on to observe geysers on Neptune's moon Triton, showing the first evidence of active cryovolcanism. The Galileo mission in the late 1990s revealed that volcanism on Io is more widespread than previously thought, and that relatively recent activity may have occurred on Europa and Ganymede. In the last few years, Mars missions have shown that volcanism on the Red Planet is more recent than previously thought, and Cassini showed dramatic active plumes on Saturn's moon Enceladus. Features thought to be volcanic have been shown to exist on Titan's very young surface, raising the possibility that active or recently active cryovolcanism may have been present there. Active volcanism offers a glimpse into the interior workings of planetary bodies, showing how eruption styles are affected by planetary variables. This talk will explore the contrasts of the various volcanic eruptions on the planets, and discuss the conditions that have made the eruption mechanisms different, while some resulting landforms are remarkably like those on Earth.