Pluvial lake
Encyclopedia
A pluvial lake is a landlocked basin (endorheic basin) which fills with rainwater during times of glaciation, when precipitation is higher. Pluvial lakes that have since evaporated and dried out may also be referred to as paleolakes.
cycle — wet cycles generate large lakes, whereas dry cycles cause the lakes to dry up leaving large flat plains. Accumulated sediments show the variation in water level. During glacial periods, times when the lake level is fairly high, mud sediments will settle out and be deposited. At times in between glaciers (interglacial
), salt deposits may be present due to the arid climate and evaporation of lake water.
Several pluvial lakes formed in the southwestern United States
during the glaciation of the late Pleistocene
epoch. One of these was Lake Bonneville
in western Utah
which covered roughly 19000 square miles (49,209.8 km²). When Lake Bonneville was at its maximum water level, it was 1000 feet (304.8 m) higher than the Great Salt Lake
.
Fresh water mollusks have been found in mud deposits from the Searles Lake in California and suggest that the water temperature was about 4 degrees Celsius cooler than current temperatures. Radiocarbon dating of the youngest mud beds yield dates from 24,000 to 12,000 years ago.
During interglacial periods, the climate becomes arid once more and causes these lakes to evaporate and dry up.
Geology
They represent changes in the hydrologicalHydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
cycle — wet cycles generate large lakes, whereas dry cycles cause the lakes to dry up leaving large flat plains. Accumulated sediments show the variation in water level. During glacial periods, times when the lake level is fairly high, mud sediments will settle out and be deposited. At times in between glaciers (interglacial
Interglacial
An Interglacial period is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age...
), salt deposits may be present due to the arid climate and evaporation of lake water.
Several pluvial lakes formed in the southwestern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
during the glaciation of the late Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
epoch. One of these was Lake Bonneville
Lake Bonneville
Lake Bonneville was a prehistoric pluvial lake that covered much of North America's Great Basin region. Most of the territory it covered was in present-day Utah, though parts of the lake extended into present-day Idaho and Nevada. Formed about 32,000 years ago, it existed until about 14,500 years...
in western Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
which covered roughly 19000 square miles (49,209.8 km²). When Lake Bonneville was at its maximum water level, it was 1000 feet (304.8 m) higher than the Great Salt Lake
Great Salt Lake
The Great Salt Lake, located in the northern part of the U.S. state of Utah, is the largest salt water lake in the western hemisphere, the fourth-largest terminal lake in the world. In an average year the lake covers an area of around , but the lake's size fluctuates substantially due to its...
.
Fresh water mollusks have been found in mud deposits from the Searles Lake in California and suggest that the water temperature was about 4 degrees Celsius cooler than current temperatures. Radiocarbon dating of the youngest mud beds yield dates from 24,000 to 12,000 years ago.
Formation
When warm air from arid regions meets chilled air from glaciers, it creates cloudy, cool, rainy weather beyond the terminus of the glacier. This kind of humid climate was present during the last glacial period in North America and causes there to be more precipitation than evaporation. The increase in rainfall and moisture fills the drainage basin and forms a lake.During interglacial periods, the climate becomes arid once more and causes these lakes to evaporate and dry up.
See also
- Lake BonnevilleLake BonnevilleLake Bonneville was a prehistoric pluvial lake that covered much of North America's Great Basin region. Most of the territory it covered was in present-day Utah, though parts of the lake extended into present-day Idaho and Nevada. Formed about 32,000 years ago, it existed until about 14,500 years...
- Lake EyreLake EyreLake Eyre is the lowest point in Australia, at approximately below sea level, and, on the rare occasions that it fills, it is the largest lake in Australia and 18th largest in the world...
, AustraliaAustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area... - Lake LahontanLake LahontanLake Lahontan was a large endorheic Pleistocene lake of modern northwestern Nevada that extended into northeastern California and southern Oregon...
- Lake ManixLake ManixLake Manix is a former lake fed by the Mojave River in the Mojave Desert of San Bernardino County, California.-Pluvial lake:During the Pleistocene era , this ancient pluvial lake occupied the modern Afton Lake, Troy Lake, Coyote Lake, Harper Lake, and Koehn Lake, and Cronese Lake basins, and when...
- Lake ManlyLake ManlyLake Manly is a pluvial, former freshwater, endorheic, rift lake that filled the Death Valley basin of Inyo County, California through the Holocene before the area's climate changed to desert. Following its isolation from the Colorado River system, Lake Manly receded by evaporation with Badwater...
- Proglacial lakeProglacial lakeIn geology, a proglacial lake is a lake formed either by the damming action of a moraine or ice dam during the retreat of a melting glacier, or by meltwater trapped against an ice sheet due to isostatic depression of the crust around the ice...