Pothole (landform) in the context of The Dakotas


Pothole (landform) in the context of The Dakotas

⭐ Core Definition: Pothole (landform)

In Earth science, a pothole is a smooth, bowl-shaped or cylindrical hollow, generally deeper than wide, found carved into the rocky bed of a watercourse. Other names used for riverine potholes are pot, (stream) kettle, giant's kettle, evorsion, hollow, rock mill, churn hole, eddy mill, and kolk. Although somewhat related to a pothole in origin, a plunge pool (or plunge basin or waterfall lake) is the deep depression in a stream bed at the base of a waterfall. It is created by the erosional forces of turbulence generated by water falling on rocks at a waterfall's base where the water impacts. Potholes are also sometimes referred to as swirlholes. This word was created to avoid confusion with an English term for a vertical or steeply inclined karstic shaft in limestone. However, given widespread usage of this term for a type of fluvial sculpted bedrock landform, pothole is preferred in usage to swirlhole.

The term pothole is also used to refer to other types of depressions and basins that differ in origin. For example, some authors refer to panholes found in the Colorado Plateau also as potholes. Other terms used for panholes are gnamma (Australia), opferkessel (German, roughly “sacrificial basin”), armchair hollows, weathering pans (or pits) and solution pans or solution pits. In another case, the term pothole is used to refer to a shallow depression, generally less than 10-acre (4.0 ha) in area that occurs between dunes or on subdued morainic relief on a prairie, as in Minnesota and the Dakotas, and often contains an intermittent pond or marsh that serves as a nesting place for waterfowl.

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Pothole (landform) in the context of Prairie Pothole Region

The Prairie Pothole Region (PPR) is an expansive area of the northern Great Plains that contains thousands of shallow wetlands known as potholes. These potholes are the result of glacier activity in the Wisconsin glaciation, which ended about 10,000 years ago. The decaying ice sheet left behind depressions formed by the uneven deposition of till as buried ice blocks melted in ground moraines. These depressions are called potholes, glacial potholes, kettles, or kettle lakes. They fill with water in the spring, creating wetlands, which range in duration from temporary to semi-permanent. The region covers an area of about 800,000 sq. km and expands across three Canadian provinces (Saskatchewan, Manitoba, and Alberta) and five U.S. states (Minnesota, Iowa, North and South Dakota, and Montana). The hydrology of the wetlands is variable, which results in long term productivity and biodiversity. The PPR is a prime spot during breeding and nesting season for millions of migrating waterfowl.

View the full Wikipedia page for Prairie Pothole Region
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