Deep below Death Valley"s charred surface, blazing hot magma once gushed up through a geologic fault until it hit groundwater. The magma quickly turned the water to steam, and like a defective subterranean pressure cooker, the Earth"s crust blew its top in a ferocious explosion. The hydrovolcanic eruption sent up a mushroom cloud of steam and spewed burnt volcanic cinders for miles. It also left the giant crater seen in this photo and 12 smaller ones spread across the surface.