Nowhere else in the world can we find the array or number of geysers, hot springs, mud pots, and fumaroles found in Yellowstone. More than 75% of the world's geysers, including the world's largest are here in 7 major basins. Steamboat, the world's tallest active geyser, is in the Norris Geyser Basin. Old Faithful, Grand, Castle, Giantess, Beehive, and Lion geysers may be frequently observed in the Upper Geyser Basin. Old Faithful Geyser has never been either the largest or most regular of geysers-yet, it has been the most regular and frequent geyser that erupts to a height of more than 100 feet; the average time between eruptions ranges between about 66 and 80 minutes, although occasionally visitors must wait two hours between eruptions of Old Faithful. For other major geysers in the Old Faithful and Norris geyser basins, eruption frequencies, durations, and heights change fairly often, especially in response to seismic activity; park visitors will find the most current information about specific geyser behavior patterns available at the Old Faithful Visitor Center or the Norris Museum.

The park's thermal features lie in the only essentially undisturbed geyser basins left worldwide. In Iceland and New Zealand, geothermal drill holes and wells 2.5 - 6.2 miles distant have reduced geyser activity and hot spring discharge. Despite the proximity of roads and trails in the largest basins, few park features have ever been diverted for human use (such as bathing pools or energy). YNP offers visitors and scientists an opportunity to appreciate thermal features in their natural, changing state. For example, research on thermophilic bacteria, algae mats, predators, and their environments is applied elsewhere to energy fuel production and extraction, bio-mining, control and removal of toxic wastes, development of new surfactants and fermentation processes, and other fields.

Park features have always been subject to some influence from human vandalism. In the park's early years it was common for visitors to use thermal features as "wishing wells", and this practice continues to some degree today. Coins, rocks, trash, logs or stumps, and other paraphernalia are found in the narrow vents of geysers and hot springs. Features have been plugged up, and little can be done to repair the damage. Radical attempts to siphon surface water and induce eruptions have occasionally been tried on famous features such as Morning Glory Pool, with varying degrees of success. Damage also occurs when people leave walkways and climb on features, or occasionally break pieces of sinter or travertine off for souvenirs (Marler 1973).

Features can also be affected by nearby ground-disturbing activities. The presence of water, sewer, and other utility systems adjacent to thermal areas has likely affected features in the past. Since many major features are located near roads and developed areas, major maintenance and construction activities must be carefully designed and monitored so as not to alter thermal features.

Periodically, applications are made for geothermal leases in Known Geothermal Resource Areas (KGRAs) outside the park, such as in the Island Park KGRA west of the park, and the Corwin Springs KGRA north of YNP near LaDuke Hot Springs. A rapid change in energy economics could increase pressure to open non-federal lands to leasing and drilling activity. Thus, research is needed to determine the extent to which YNP's geothermal systems connect with areas of lease application west and north of the boundary.

Volcanic and seismic processes are very active in the park. A network of seismic monitoring stations in the park provides data to help understand overall seismicity in the region and gauge the magnitude of earth tremors. Thermal features and basins respond violently to volcanic/seismic activity, which creates both a serious hazard to humans and an opportunity to study and possibly predict major geologic hazards. Thus, maintenance of a long-term geothermal data base also helps us manage visitor use to increase public safety in a naturally hazardous environment.

Legislative restrictions on geothermal development around Yellowstone, such as the Old Faithful Protection Act introduced in 1992, have failed to pass Congressional approval. In 1994, the NPS and the state of Montana agreed to monitor and control the use of hot, warm, and cold groundwater in areas just north of the park. Proponents of water use must show that proposed geothermal development will not adversely affect park features. This Water Rights Compact could serve as a model for agreements between the park and other states to ensure the continued flow of heat and water to Yellowstone's famous geysers and hot springs.


References
Marler, George. 1973. Inventory of Thermal Features of the Firehole River Geyser Basins and Other Selected Areas of Yellowstone National Park. Natl. Tech. Info. Serv., U.S. Dept. Commerce. Pub. PB221 289. 652p.

Geyser Activity

Non-NPS sources of additional geothermal information include:
Yellowstone Hotspot - courtesy of Bob Smith, University of Utah
Yellowstone Geysers - courtesy of David Montieth & Contributors