map of the Mono Basin area, showing the
Long Valley Caldera (
click to see detail). In
hydrothermal systems, the circulation of
ground water is driven by a combination of topography and
geothermal heat sources. The system in the Long Valley Caldera is recharged primarily from snowmelt in the highlands around the western and southern rims of the caldera. The meltwater infiltrates to depths of a few kilometers (or miles), where some is heated to at least by hot rock near the
Inyo craters. The heated water, kept from boiling by high pressure, still has lower density than cold water, and it rises along steeply inclined fractures to depths of . It then flows eastward through rock layers to
hydrothermal vent discharge points at the surface along Hot Creek and around
Crowley Lake. The water temperature declines eastward because of heat loss and mixing with cold water, and in the springs near Crowley Lake temperatures are at only about . The
springs in Hot Creek all emerge along a stream section between two faults and discharge a total of about of hot water. This water flow represents nearly 70 percent of the total heat discharged by all thermal springs in Long Valley Caldera. The thermal springs farther east all discharge less water and at lower temperatures. ==Access==