Images Dated 15th October 2010

Detail of West Thumb Geyser Basin emptying into Yellowstone Lake, Wyoming, USA

The West Thumb Geyser Basin, including Potts Basin to the north, is the largest geyser basin on the shores of Yellowstone Lake. Generally all geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. Surface water works its way down to an average depth of around 2, 000 meters where it contacts hot rocks. The resultant boiling of the pressurized water results in the geyser effect of hot water and steam spraying out of the geysers surface vent

© Judith Zimmerman/Danita Delimont