Terrestrial Analogs to Planetary Volcanic Processes

Abstract

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Planetary Science. Please check back later for the full article. More than 50 years of solar system exploration has revealed the great diversity of volcanic landscapes beyond the Earth, be they formed by molten rock, liquid water, or other volatile species. Classic examples of giant shield volcanoes, solidified lava flows, extensive ash deposits, and volcanic vents can all be identified but, with the exception of eruptions seen on the Jovian moon Io, none of these planetary volcanoes have been observed in eruption. Consequently, the details of the processes that created these landscapes must be inferred from the available spacecraft data. Despite the increasing improvement in the spatial, temporal, compositional, and topographic characteristics of the data for planetary volcanoes, details of the manner in which they formed are not clear. However, terrestrial eruptions can provide numerous insights into planetary eruptions, whether they result in the emplacement of lava flows, explosive eruptions due to volatiles in the magma, or the interaction between hot lava and water or ice. In recent decades, growing attention has therefore been directed at the use of terrestrial analogs to help interpret volcanic landforms and processes on the terrestrial planets (Mercury, Venus, the Moon, and Mars) and in the outer solar system (the moons of Jupiter and Saturn, the larger asteroids, and potentially Pluto). In addition, terrestrial analogs not only provide insights into the geologic processes associated with volcanism, but they can also serve as test sites for the development of instrumentation to be sent to other worlds, as well as serve as a training ground for manned and unmanned explorers seeking to better understand volcanism throughout the solar system.