Volcano Type: Calderas
Volcano Status: Tephrochronology
Last Known Eruption: 1350 BC ± 200 years
Summit Elevation: 2805 m 9,203 feet
Latitude: 44.43°N 44°26’0″N
Longitude: 110.67°W 110°40’0″W
The Yellowstone Caldera, sometimes known as the Yellowstone supervolcano, is a volcanically active region in Yellowstone National Park. It measures 55 kilometers (34 mi) by 72 kilometers (44 mi). Yellowstone, like the Hawaiian Islands, is believed to lie on top of one of the planet’s few dozen hotspots where light hot molten mantle rock rises towards the surface.
The Yellowstone Plateau volcanic field developed through three volcanic cycles spanning two million years that included some of the world’s largest known eruptions. Eruption of the >2450 cu km Huckleberry Ridge Tuff about 2.1 million years ago created the more than 75-km-long Island Park caldera. The second cycle concluded with the eruption of the Mesa Falls Tuff around 1.3 million years ago, forming the 16-km-wide Henrys Fork caldera at the western end of the first caldera. Activity subsequently shifted to the present Yellowstone Plateau and culminated 640,000 years ago with the eruption of the >1000 cu km Lava Creek Tuff and the formation of the present 45 x 85 km caldera. Resurgent doming subsequently occurred at both the NE and SW sides of the caldera and voluminous (1000 cu km) intracaldera rhyolitic lava flows were erupted between 150,000 and 70,000 years ago. No magmatic eruptions have occurred since the late Pleistocene, but large hydrothermal eruptions took place near Yellowstone Lake during the Holocene. Yellowstone is presently the site of one of the world’s largest hydrothermal systems including Earth’s largest concentration of geysers.
An eruption of Old Faithful, perhaps the world’s best known geyser, rises above Yellowstone’s Upper Geyser Basin. Old Faithful is a periodic geyser, with eruptions to heights of about 40 m at intervals of 30 to 100 minutes. Old Faithful Lodge to the right provides a rustic backdrop to the Upper Geyser Basin, which contains more geysers than are known altogether in the rest of the world. The forested ridge in the background is underlain by massive post-caldera rhyolitic lava flows of the Madison Plateau.
Originally posted 2010-08-19 04:23:32.





