A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma or by circulation through faults to hot rock deep in the Earth's crust. In either case, the ultimate source of the heat is radioactive decay of naturally occurring radioactive elements in the Earth's mantle, the layer beneath the crust.
Geothermal energy is the thermal energy in the Earth's crust which originates from the formation of the planet and from radioactive decay of materials in currently uncertain but possibly roughly equal proportions. The high temperature and pressure in Earth's interior cause some rock to melt and solid mantle to behave plastically. This results in parts of the mantle convecting upward since it is lighter than the surrounding rock. Temperatures at the core–mantle boundary can reach over 4000 °C (7200 °F).
The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles. The number of thermal features in Yellowstone is estimated at 10,000. A study that was completed in 2011 found that a total of 1,283 geysers have erupted in Yellowstone, 465 of which are active during an average year. These are distributed among nine geyser basins, with a few geysers found in smaller thermal areas throughout the Park. The number of geysers in each geyser basin are as follows: Upper Geyser Basin (410), Midway Geyser Basin (59), Lower Geyser Basin (283), Norris Geyser Basin (193), West Thumb Geyser Basin (84), Gibbon Geyser Basin (24), Lone Star Geyser Basin (21), Shoshone Geyser Basin (107), Heart Lake Geyser Basin (69), other areas (33). Although famous large geysers like Old Faithful are part of the total, most of Yellowstone's geysers are small, erupting to only a foot or two. The hydrothermal system that supplies the geysers with hot water sits within an ancient active caldera. Many of the thermal features in Yellowstone build up sinter, geyserite, or travertine deposits around and within them.
A spring is a point of exit at which groundwater from an aquifer flows out on top of Earth's crust (pedosphere) and becomes surface water. It is a component of the hydrosphere. Springs have long been important for humans as a source of fresh water, especially in arid regions which have relatively little annual rainfall.
Geothermal heating is the direct use of geothermal energy for some heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004. As of 2007, 28 GW of geothermal heating capacity is installed around the world, satisfying 0.07% of global primary energy consumption. Thermal efficiency is high since no energy conversion is needed, but capacity factors tend to be low since the heat is mostly needed in the winter.
Harbin Hot Springs is a non-profit hot spring retreat and workshop center at Harbin Springs in Lake County, Northern California. Named after Matthew Harbin, a pioneer who settled in the Lake County area. It is located about two hours northeast of the San Francisco Bay Area, in the United States. The facility was partially destroyed in the Valley Fire in September 2015, and was temporarily closed. In January 2019 it partially reopened, including the main pools and sauna, and a limited cafeteria service.
Steamboat Springs is a small volcanic field of rhyolitic lava domes and flows in western Nevada, located south of Reno. There is extensive geothermal activity in the area, including numerous hot springs, steam vents, and fumaroles. The residential portions of this area, located mostly east of Steamboat Creek and south of modern-day SR 341, are now known simply as Steamboat.
Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 26 countries, while geothermal heating is in use in 70 countries.
Hot Creek, starting as Mammoth Creek, is a stream in Mono County of eastern California, in the Western United States. It is within the Inyo National Forest.
Hunters Hot Springs are natural geothermal springs located in Lake County, Oregon, 2 miles (3 km) north of Lakeview. The springs are named after Harry Hunter, who bought the springs in 1923. The best known feature within the geothermal area is Old Perpetual, which is Oregon's only continuously erupting geyser. The geyser was formed as a result of a well drilling attempt while Hunter was developing a health resort at the springs.
Scovern Hot Springs is a thermal spring system, and former settlement in the Kern River Valley of the Southern Sierra Nevada, in Kern County, California.
Adams is an unincorporated community in Lake County, California. It was formerly Adams Springs, a summer resort developed around a small group of mineral water springs.
Highland Springs is a set of springs which was turned into a resort in the 19th century in Lake County, California. The resort grew to be able to accommodate 200 people, attracted by the curative powers of the mineral waters and the lovely mountain scenery. In the 1920s its popularity waned, the hotel was partly burned, and it passed through various hands before the county claimed eminent domain, bought the property, and flooded it with the Highland Springs Reservoir. The reservoir is surrounded by the Highland Springs Recreation Area, managed by the county.
Howard Springs is set of springs turned into a resort in the 1870s in Lake County, California. The resort catered primarily to people interested in the curative powers of the mineral waters. Guests were accommodated in cabins or tents. At one time it had an official post office. The resort changed hands many times over the years, with various changes to the lodge, accommodations and bathhouses, until closing in 1970. For a period it was leased for geothermal exploration. Today it has reopened as a health resort.
Newman Springs is a set of springs in Lake County, California. At one time there was a resort at the springs.
Saratoga Springs is set of springs that was turned into a resort in the 1870s in Lake County, California. At its peak the resort could accommodate 250 people. The resort was closed after the main hotel burned down, but reopened as a retreat in 1991.
Seigler Springs is a set of springs in Lake County, California around which a resort developed in the 19th century. In the 1930s the resort was expanded, and in 1947 an airport opened nearby. The resort declined in the 1960s. Part of it was separated out and became a residential subdivision, while part became a religious retreat. The 2015 Valley Fire caused great damage.
Bimini Baths was a geothermal mineral water public bathhouse and plunge in what is now Koreatown, Los Angeles, California, US. It was situated just west of downtown, near Third Street and Vermont Avenue. Bimini Baths contained a natatorium, swimming pools, swimming plunge, Turkish baths, a medical treatment department, and bottling works.
The Yangbajain Geothermal Field (羊八井地热田) is a geothermal field near the town of Yangbajain in Damxung County, Tibet Autonomous Region, China. The fluid is heated by magmatic activity not far below the surface. It is a tourist attraction and also supplies steam to a major power plant with 25 MW capacity. Concerns have been raised that untreated waste water is polluting the river downstream from the power plant,
Summer Lake Hot Springs are natural hot springs at the south end of Summer Lake in south-central Oregon. They are artesian mineral springs with four surface sources. The springs have complex water chemistry. The temperature of the main source is approximately 123 °F (51 °C) with a water flow of approximately 20 US gallons (76 L) per minute. Over the years, the site has been developed as a rustic family bathing and relaxation resort. The hot springs are 124 miles (200 km) southeast of Bend, Oregon, near the small town of Paisley, Oregon.
