A geyser is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in a few places on Earth. Generally all geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. Generally, surface water works its way down to an average depth of around 2,000 metres (6,600 ft) 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 geyser's surface vent.
Long Valley Caldera is a depression in eastern California that is adjacent to Mammoth Mountain. The valley is one of the Earth's largest calderas, measuring about 20 mi (32 km) long (east-west), 11 mi (18 km) wide (north-south), and up to 3,000 ft (910 m) deep.
A fumarole is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcanic activity, but fumarole activity can also precede a volcanic eruption and has been used for eruption prediction. Most fumaroles die down within a few days or weeks of the end of an eruption, but a few are persistent, lasting for decades or longer. An area containing fumaroles is known as a fumarole field.
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 mudpot, or mud pool, is a sort of acidic hot spring, or fumarole, with limited water. It usually takes the form of a pool of bubbling mud. The acid and microorganisms decompose surrounding rock into clay and mud.
Lassen Volcanic National Park is an American national park in northeastern California. The dominant feature of the park is Lassen Peak, the largest plug dome volcano in the world and the southernmost volcano in the Cascade Range. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcano can be found—plug dome, shield, cinder cone, and stratovolcano.
The Lassen volcanic area presents a geological record of sedimentation and volcanic activity in and around Lassen Volcanic National Park in Northern California, U.S. The park is located in the southernmost part of the Cascade Mountain Range in the Pacific Northwest region of the United States. Pacific Oceanic tectonic plates have plunged below the North American Plate in this part of North America for hundreds of millions of years. Heat and molten rock from these subducting plates has fed scores of volcanoes in California, Oregon, Washington and British Columbia over at least the past 30 million years, including these in the Lassen volcanic areas.
Lassen Peak, commonly referred to as Mount Lassen, is a lava dome volcano and the southernmost active volcano in the Cascade Range of the Western United States. Located in the Shasta Cascade region of Northern California, it is part of the Cascade Volcanic Arc, which stretches from southwestern British Columbia to northern California. Lassen Peak reaches an elevation of 10,457 ft (3,187 m), standing above the northern Sacramento Valley. It supports many flora and fauna among its diverse habitats, which are subject to frequent snowfall and reach high elevations.
Chaos Crags is the youngest group of lava domes in Lassen Volcanic National Park, California. They formed as six dacite domes 1,100-1,000 years ago, one dome collapsing during an explosive eruption about 70 years later. The eruptions at the Chaos Crags mark one of just three instances of Holocene activity within the Lassen volcanic center. The cluster of domes is located north of Lassen Peak and form part of the southernmost segment of the Cascade Range in Northern California. Each year, a lake forms at the base of the Crags, and typically dries by the end of the summer season.
Krafla is a volcanic caldera of about 10 km in diameter with a 90 km long fissure zone. It is located in the north of Iceland in the Mývatn region and is situated on the Iceland hotspot atop the Mid-Atlantic Ridge, which forms the divergent boundary between the North American Plate and the Eurasian Plate. Its highest peak reaches up to 818 m and it is 2 km in depth. There have been 29 reported eruptions in recorded history.
Kendall VanHook Bumpass was a cowboy and early settler, who, in 1865, broke through the surface of a scalding hot mudpot in an active geothermal area and consequently lost a leg by amputation. The geothermal area was later named "Bumpass Hell", and is today located in Lassen Volcanic National Park in California.
Mount Tehama is an eroded andesitic stratovolcano in the Cascade Volcanic Arc and the Cascade Range in Northern California. Part of the Lassen volcanic area, its tallest remnant, Brokeoff Mountain, is itself the second highest peak in Lassen Volcanic National Park and connects to the park's highest point, Lassen Peak. Located on the border of Tehama County and Shasta County, Brokeoff's peak is the highest point in the former. The hikers that summit this mountain each year are treated to "exceptional" views of Lassen Peak, the Central Valley of California, and many of the park's other features. On clear days, Mount Shasta can also be seen in the distance.
The Boiling Lake is a flooded fumarole located in Morne Trois Pitons National Park, a World Heritage Site on the island of Dominica. The lake, located 6.5 miles (10.5 km) east of Dominica's capital Roseau, is filled with bubbling greyish-blue water that is usually enveloped in a cloud of vapour. The Boiling Lake is approximately 200 to 250 feet across and is the second-largest hot lake in the world after Frying Pan Lake, located in Waimangu Valley near Rotorua, New Zealand.
Morne Trois Pitons National Park is a national park in Dominica established in July 1975, the first to be legally established in the country. It became a World Heritage Site in 1997. The park is named after its highest mountain, Morne Trois Pitons, meaning mountain of three peaks. The park is an area of significant volcanic activity. Features within the park include the Valley of Desolation, a region of boiling mud ponds and small geysers; the Boiling Lake; Titou Gorge; and Emerald Pool. The mountain is the second-highest peak in Dominica, being exceeded only by Morne Diablotins.
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.
Tikitere, also known as "Hell's Gate", is a suburb in Rotorua's most active geothermal area on State Highway 30, between Lake Rotorua and Lake Rotoiti in the Bay of Plenty, New Zealand. It includes many geothermal features such as steaming lakes, mudpools, fumaroles, a mud volcano and the Kakahi Falls, the largest hot waterfall in the southern hemisphere.
The Olkaria Area is a region located immediately to the south of Lake Naivasha in the Great Rift Valley of Kenya, Africa. It is geothermally active and is being used to generate clean electric power. The region has an estimated potential of 2,000 MW. This is almost double the maximum daily electricity peak demand recorded in 2008/2009 for the entire country.
Seltún Hot Springs, Icelandic pronunciation: [ˈsɛlˌtʰuːn], is a geothermal hot spring system in Krýsuvík volcanic area, in southwest Iceland on the Mid-Atlantic Ridge of the Reykjanes peninsula.
Hveravellir is a geothermal field of the Oddnýjarhnjúkur-Langjökull [ˈɔtːˌniːjarˌn̥juːkʏr̥] subglacial volcanic system in the north of Langjökull glacier.
Geothermal activity is a group of natural heat transfer processes, occurring on Earth's surface, caused by the presence of excess heat in the subsurface of the affected area. Geothermal activity can manifest itself in a variety of different phenomena, including, among others, elevated surface temperatures, various forms of hydrothermal activity, and the presence of fumaroles that emit hot volcanic gases.
