HR: 08:30h
AN: V31A-03 INVITED     [Abstracts]
TI: Beyond Earth: How extra-terrestrial volcanism stretches our definition of a volcano
AU: * Lopes, R
EM: rosaly.m.lopes@jpl.nasa.gov
AF: Jet Propulsion Laboratory, Caltech, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AB: 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 past volcanism, some in unexpected places. Volcanism in extraterrestrial worlds can be much different from the examples we see on Earth, but 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. The discovery of numerous extra-terrestrial volcanoes, including active ones, has stretched our traditional definition of what is a volcano. 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. Io's volcanism is driven by tidal dissipation, fundamentally different from what causes volcanism on Earth. To date, no planet outside the Earth shows evidence of plate tectonics. Despite these differences, the eruption styles and products on other planets show great similarity to Earth's. Voyager went on to observe geysers on Neptune's moon Triton, showing the first evidence of cryovolcanism, a process that has no terrestrial analogue but which appears to be widespread in the outer solar system. The Galileo spacecraft showed that relatively recent cryovolcanic activity may have occurred on Europa and Ganymede. In the last few years, the Cassini spacecraft 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. As we continue our exploration of the solar system, we need to redefine the fundamental geologic processes using a planetary rather than terrestrial context.
DE: 8499 General or miscellaneous
SC: Volcanology, Geochemistry, and Petrology [V]
MN: 2007 Joint Assembly