Carbon-Dioxide-Driven, Cold-Water Geysers
J. Alan Glennon, 6 May 2005

The activity of cold-water geysers is similar to their hot water counterparts, except that CO2 bubbles drive the eruption instead of steam. In cold-water geysers, CO2-laden water lies in a confined aquifer, in which water and CO2 are trapped by less permeable overlying strata. Only in a handful of places, such as at faults, joints, or drilled wells, can the water and CO2 readily escape the underlying aquifer. If a well is drilled through a confining layer into a CO2-laden aquifer, the borehole provides a path for the pressurized water and CO2 to reach the surface. Faults and joints also may provide routes for gas-laden water to penetrate an overlying confining layer. Aquifer and plumbing attributes, including plumbing depth, CO2 concentrations, aquifer yield, and so on, combine to provide the differing scales and frequencies of eruptions.

Analogous to steam bubbles expanding to displace water in a hot water geyser, the column of water in a cold-water geyser’s plumbing exerts enough pressure to keep the CO2 in solution and in small bubbles. A decrease in pressure of the water column allows CO2 to outgas and any existing CO2 bubbles to expand. This “boiling” deep in the system is comparable to water flashing to steam in a hot water geyser. As the CO2 outgasses, it displaces water and starts the eruption.

Crystal Geyser, Utah
J. Alan Glennon, photos from 1995 and 2000
(Click on thumbnail for a larger image) In an unsuccessful attempt to increase Crystal's eruptions, someone filled the erupting pool with debris; see images 'cry2000d.jpg' and 'back1995d.jpg' which are taken from similar vantage points five years apart.

At Crystal Geyser, in southeast Utah, after a geyser eruption, the geyser vent is calm and the water level is below the surface; like many cold water geysers, Crystal Geyser is a drilled well. As time passes, water begins to fill the well column. The well itself penetrates a confined aquifer with a hydraulic head above the level of the ground surface, thus the well, if not for the geyser-like behavior, the well would be expected to possess artesian discharge. When CO2 and water make it to the surface, CO2 degassing manifests as increasingly agitated boiling at the vent. Each of these agitations causes a pressure release for the CO2 below in the plumbing. Eventually, one of the agitated boils is large enough to create a chain reaction of CO2 degassing and expansion down the well: an eruption.

Roadside/Woodside Geyser, Utah
from "MirroKrome" slides by H.S. Crocker Co, Inc., Year unknown (~1960s)

Woodside Geyser 2004
J. Alan Glennon, taken 10 June 2004

Given that many, if not most, cold-water geysers are drilled wells, they rarely reside in pristine natural settings. At Source Intermittente de Vesse, France, Boiling Fount, Germany, and Herlany Geyser, Slovakia, concrete and stonework basins have been constructed around the wellheads; the geysers look like city park fountains. Only two CO2-driven, cold-water geysers—a small unnamed spouter at Salton Sea, California, and Cold Water Geyser, Yellowstone—possess both natural vents and lie in relatively undisturbed settings. The appearance of cold-water geysers may be quite similar to their steam-driven counterparts; however, often CO2-laden water is more white and frothy. Cold-water geysers are known in France, Germany, New Zealand, Serbia, Switzerland, Slovakia, and the United States.

In summary, CO2 and water are competing to get out of the ground and the effect with limited, small openings, is occasional eruptions. Aquifer and plumbing attributes (like plumbing depth, CO2 concentrations, depth to confined aquifer, aquifer yield, etc.) combine to provide the differing scales and frequencies of eruptions.

A Recent Eruption of Crystal Geyser
J. Alan Glennon, taken 10 June 2004

For more information about Cold Water Geysers, see:
Glennon, J.A. and Pfaff. R.M. (2005) The operation and geography of carbon-dioxide-driven, cold-water geysers. GOSA Transactions, vol. 9, pp. 184-192.

Crystal Geyser Dinosaur Quarry:
For information on the area's dinosaur discoveries, visit the Utah State Paleontologist's site:
The dinosaur quarry is several kilometers away from the geyser (not at Crystal Geyser itself). As such, please do not disturb or break the travertine deposits at the geyser site.

MPEGs of Crystal Geyser erupting:

Hot Water Geysers:
For more information about hot water geysers, visit:

To reference this material, use the appropriate variation of the following format:
J. Alan Glennon. (2005) Carbon Dioxide-Driven, Cold Water Geysers,, University of California, Santa Barbara, originally posted February 12, 2004, last update 6 May 2005.

Please contact me if you have questions or comments (particularly if you notice an error).

J. Alan Glennon
Department of Geography
University of California
Santa Barbara, California 93106