Ubehebe Crater

Ubehebe Crater sits in northern Death Valley National Park, Inyo County, California, about 0.8 kilometers across and 150 to 240 meters deep. It is a maar, a crater produced by a phreatomagmatic eruption: rising magma along a fault at the base of nearby Tin Mountain came close enough to the surface to flash groundwater into steam, and the resulting explosion blew out large quantities of pulverized old rock mixed with new magma across the surrounding alluvial fan, with the blast force estimated at ten times the tensile strength of the local bedrock. One explosion is thought to have produced a base surge, a fast-moving, doughnut-shaped cloud of ash and gas traveling at an estimated 100 to 200 miles per hour that coated the surrounding landscape, leaving cinder deposits near the crater up to 80 feet thick. Ubehebe was the largest of a series of similar eruptions in the area, most recently estimated at somewhere between 2,000 and 7,000 years old, though a 2012 study suggested the youngest activity could be as recent as 800 years ago. This entity documents Ubehebe Crater specifically as a geological formation produced by a steam-driven volcanic explosion.