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Lunar Geologists Analyze Shield Volcanoes

Much of the Moon's surface is covered by lava flows, the dark smooth areas seen on the Moon (or lunar maria), but few real volcanoes had been seen from orbital imagery. On Earth, most lava flows are associated with large shield (low-angle) volcanoes, like those on the Hawaiian islands. Data from the Lunar Reconnaissance Orbiter (LRO) camera, interpreted by scientists at USRA's Lunar and Planetary Institute, showed that the Moon also has several such large shield volcanoes. Because their slopes are so low (a few degrees, on average), these shield volcanoes are essentially invisible in photographs; however, in the new LRO elevation map (see figure, right image), they are quite obvious. This elevation map revealed one specific area to be a prominent topographic swell, also known as a shield volcano, measuring ~560 km across and over 1800 meters tall and named Cauchy after a nearby crater. USRA lunar scientists analyzed the surface geology of the Cauchy volcano to more clearly understand the Moon's interior processes that are responsible for the volcano's formation and location.