What is Yellowstone Caldera?
[[File:Yellowstone River in Hayden Valley.jpg|thumb|250px|The caldera]] The '''Yellowstone Caldera''' is a [[volcano|volcanic]] [[caldera]] and [[supervolcano]] in [[Yellowstone National Park]] in the [[Western United States]]. It is sometimes referred to as the Yellowstone Supervolcano. The caldera and most of the park are in the northwest corner of [[Wyoming]]. The caldera is about 55 by 72 [[km]]. It was formed during the last of the three supereruptions that occurred over the last 2.1 million years. A '''caldera''' is a large [[cauldron]]-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. It's what is left after the explosion. Volcanism at Yellowstone is relatively recent. The calderas lie over a [[hotspot (geology)|hotspot]] under the Yellowstone Plateau. Light and hot [[magma]] (molten rock) from the [[mantle (geology)|mantle]] rises toward the surface. The hotspot is much deeper than the terrain: it is ''stationary'', while the [[North American Plate]] moves west-southwest over it.<ref>{{cite web| title = Yellowstone Caldera, Wyoming—USGS| work = Cascade Volcano Observatory| publisher = [[United States Geological Survey]]| date = January 22, 2003| url = http://vulcan.wr.usgs.gov/Volcanoes/Yellowstone/description_yellowstone.html | access-date = December 30, 2008}}</ref> Calderas appear to move, but this is an illusion. The plates of the Earth move, and hot spots stay in the same place (see [[Hawaiian Islands]]). As the [[Americas]] moved west, they ran over one or two hot spots. This is the one now in [[Wyoming]]. == References == {{reflist}} {{-}} {{US-stub}} {{authority control}} [[Category:Volcanoes of the United States]] [[Category:VEI-8 volcanoes]] [[Category:Calderas]] [[Category:Geography of Wyoming]] [[Category:National parks in the United States]]