A mudpot, or mud pool, is a sort of acidic

hot spring 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 (molten rock) or by c ...

, or

fumarole A fumarole (or fumerole) 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 volcani ...

, 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.

Description

The mud of a mudpot takes the form of a

viscous The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the inte ...

, often bubbling, slurry. As the boiling mud is often squirted over the brims of the mudpot, a sort of mini-volcano of mud starts to build up, sometimes reaching heights of 1 to 1.5 meters. Although mudpots are often called "mud volcanoes", true

mud volcano A mud volcano or mud dome is a landform created by the eruption of mud or slurries, water and gases. Several geological processes may cause the formation of mud volcanoes. Mud volcanoes are not true igneous volcanoes as they do not produce la ...

es are very different in nature. The mud of a mudpot is generally of white to greyish color, but is sometimes stained with reddish or pink spots from

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

compounds. When the slurry is particularly colorful, the feature may be referred to as a paint pot.

Geology

Mudpots form in high-temperature geothermal areas where water is in short supply. The little water that is available rises to the surface at a spot where the soil is rich in

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

ash,

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

, and other fine particulates. The thickness of the mud usually changes along with seasonal changes in the

water table The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated. T ...

Notable sites

The

geothermal areas of Yellowstone 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, ...

National Park contain several notable examples of both mudpots and paint pots, as do some areas of

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of t ...

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

and

Nicaragua Nicaragua (; ), officially the Republic of Nicaragua (), is the largest country in Central America, bordered by Honduras to the north, the Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to the west. Managua is the countr ...

. Several locations in and around the

Salton Sea The Salton Sea is a shallow, landlocked, highly saline body of water in Riverside and Imperial counties at the southern end of the U.S. state of California. It lies on the San Andreas Fault within the Salton Trough that stretches to the Gulf ...

in California are also home to active mudpots, including the moving Niland Geyser. In the case of Niland Geyser, its name is somewhat of a misnomer, as the release of

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

by seismic activity from the nearby

San Andreas Fault The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizonta ...

is responsible for its behaviour, rather than through geothermal activity. The fluid contained within it is near background temperature rather than boiling, measuring around . Bumpass Hell in

Lassen Volcanic National Park 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 Vol ...

also contains mudpots.

Photo gallery

File:Mudpot west thumb 20190717 135010 VID.webm, A large boiling mudpot in the parking area of West Thumb Geyser Basin in

Yellowstone Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowston ...

Image:Fountain Paint Pots in Yellowstone-750px.JPG, Fountain Paint Pots,

Yellowstone National Park Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowst ...

Image:MudPot_8334.jpg, Mudpot in

Image:Yellowstone mud pot p1090998.jpg, Mudpot in Yellowstone National Park Image:RincónMudpot Apr2003.jpg, Mudpot at Rincón de la Vieja Volcano National Park, Costa Rica Image:Mud pool near Waiotapu.ogg, Short video of mud pool activity near Waiotapu,

File:Mud pool at Orakei Korako.ogv, Video of mud pool at

Orakei Korako Orakei Korako is a highly active geothermal area most notable for its series of fault-stepped sinter terraces, located in a valley north of Taupō on the banks of the Waikato River in the Taupō Volcanic Zone, New Zealand. It is also known as ...

Image:Hverir mudpool 2012-06-05.jpg, Erupting mudpot at Hverir, Iceland Image:YellowstoneMudpit.jpg, A mud pot in

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

References

External links

{{Commons category, Mudpots
Mudpots at Yellowstone National Park official site

Springs (hydrology) Volcanic landforms Volcanism Geothermal areas Articles containing video clips Volcanic degassing