Salton Sea Mud Volcanoes
January 17, 2008
Mud pots and mud volcanoes are geothermal features produced when water and/or gas is forced upward through soil and sediments. Mud pots can assume a variety of morphologies, typically being depressions or enclosed basins containing gas seeps, bubbling water or viscous mud (bottom photo). They can also be water-laden and appear as bubbling muddy water. Mud volcanoes, on the other hand, are elevated conical structures composed of accumulations of viscous mud extruded from a central vent. They range from finger-sized to several kilometers across. Small mud volcanoes on land (1 - 3 m or about 1 - 10 ft tall) are usually called mud cones or gryphons -- they're usually associated with volcanic and seismic activity.
There are dozens of mud pots and mud volcanoes near the southeastern shore of the Salton Sea in Imperial County, California. Volcanoes up to 2 m high (about 6.5 feet) ooze hot mud and steam while nearby mud pots gurgle with hot mud. Their sizes and shapes change with the availability of ground water and the amount of recent rains. Even from a distance you can hear the structures hiss and mutter as viscous mud makes its way to the surface.
These geothermal features are associated with a shallow magma body in the area. Ground water is heated and forced to the surface by CO2 produced far underground. So hot are the brines in this area that they're pumped to the surface and used to power electricity-producing turbines.