A giant's kettle, also known as either a giant's cauldron, moulin pothole, or glacial pothole, is a typically large and cylindrical

pothole A pothole is a depression in a road surface, usually asphalt pavement, where traffic has removed broken pieces of the pavement. It is usually the result of water in the underlying soil structure and traffic passing over the affected area. Wate ...

drilled in solid rock underlying a glacier either by water descending down a deep moulin or by

gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

rotating in the bed of subglacial meltwater stream.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. The interiors of potholes tend to be smooth and regular, unlike a

plunge pool A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or shut-in. It is created by the erosional forces of cascading water on the rocks at formation's base where the water impacts.Mars ...

. An example is the large pothole found in

Archbald, Pennsylvania Archbald is a borough in Lackawanna County, Pennsylvania. It is part of Northeastern Pennsylvania and is named for James Archbald, the first mayor of Carbondale, Pennsylvania. Before being renamed in Archbald's honor, the name of the settlement ...

, in

Archbald Pothole State Park Archbald Pothole State Park is a Pennsylvania state park in Archbald, Lackawanna County, Pennsylvania. The focal point of the park is Archbald Pothole. The pothole is a remnant of the Wisconsin Glacial Period, deep with a largest diameter ...

Formation

Giant's kettles are formed while a

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of be ...

surface is covered by a glacier. Water, produced by the thawing of the ice and

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughou ...

, forms

stream A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams ...

s on the surface of the glacier, which, having gathered into their courses a certain amount of morainic debris, finally flow down a

crevasse A crevasse is a deep crack, that forms in a glacier or ice sheet that can be a few inches across to over 40 feet. Crevasses form as a result of the movement and resulting stress associated with the shear stress generated when two semi-rigid p ...

as a swirling

cascade Cascade, Cascades or Cascading may refer to: Science and technology Science *Cascade waterfalls, or series of waterfalls * Cascade, the CRISPR-associated complex for antiviral defense (a protein complex) * Cascade (grape), a type of fruit * Bioc ...

or moulin. The sides of the crevasse are abraded, and a vertical shaft is formed in the ice. The

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...

may be continued into the bed of the glacier; and, the ice having left the district, the giant's kettle so formed is seen as an empty shaft, or as a

pipe Pipe(s), PIPE(S) or piping may refer to: Objects * Pipe (fluid conveyance), a hollow cylinder following certain dimension rules ** Piping, the use of pipes in industry * Smoking pipe ** Tobacco pipe * Half-pipe and quarter pipe, semi-circular ...

filled with gravel,

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...

, or

boulder In geology, a boulder (or rarely bowlder) is a rock fragment with size greater than in diameter. Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive. In ...

s. Such cavities and pipes afford valuable evidence as to the former extent of glaciers. Similar potholes are encountered in riverbeds and the Channeled Scablands scoured by glacial outburst floods.

Notable giant's kettle

''Helvete'' in

Gausdal Gausdal is a municipality in Innlandet county, Norway. It is located in the traditional district of Gudbrandsdal. The administrative centre of the municipality is the village of Segalstad bru. Other villages in Gausdal include Follebu, Forse ...

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of ...

is a

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they ar ...

about 100 meters deep with giant's kettles (''jettegryter'') up to wide and deep. The GletscherGarten of

Lucerne Lucerne ( , ; High Alemannic: ''Lozärn'') or Luzern ()Other languages: gsw, Lozärn, label= Lucerne German; it, Lucerna ; rm, Lucerna . is a city in central Switzerland, in the German-speaking portion of the country. Lucerne is the capital o ...

(

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

) is famous for its giant's kettles, having 32 in number, the largest being wide and deep. They are also common in

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

(''gletschertopf'';

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...

pot Pot may refer to: Containers * Flowerpot, a container in which plants are cultivated * Pottery, ceramic ware made by potters * A type of cookware Places * Ken Jones Aerodrome, IATA airport code POT * Palestinian Occupied Territories, the W ...

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic countries, Nordic c ...

(''jättegryta''),

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bot ...

(''hiidenkirnu''; hiisi's

churn Churn may refer to: * Churn drill, large-diameter drilling machine large holes appropriate for holes in the ground Dairy-product terms * Butter churn, device for churning butter * Churning (butter), the process of creating butter out of mil ...

), and Moss Island in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

References

External links

{{Authority control Glaciology Fluvial landforms

Formation

Notable giant's kettle

See also

References

External links