Mudpot

Mudpot in Hverir, Námafjall, Iceland

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.

Description

The mud of a mudpot takes the form of a viscous, 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 3–5 feet. Although mudpots are often called "mud volcanoes", true mud volcanoes 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 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 ash, clay and other fine particulates. The thickness of the mud usually changes along with seasonal changes in the water table.

Notable sites

The geothermal areas of Yellowstone National Park contain several notable examples of both mudpots and paint pots, as do some areas of Iceland and New Zealand. Several locations in and around the Salton Sea in California are also home to active mudpots.

Photo gallery

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  Fountain Paint Pots, Yellowstone National Park

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  Mudpot in Lassen Volcanic National Park

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  Mudpot in Yellowstone National Park

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  Mudpot at Rincón de la Vieja Volcano National Park, Costa Rica

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  Short video of mud pool activity near Waiotapu, New Zealand

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  Video of mud pool at Orakei Korako, New Zealand

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  Erupting mudpot at Hverir, Iceland

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  A mud pot in Yellowstone National Park, Wyoming