Lake Monongahela

Lake Monongahela was a proglacial lake in western Pennsylvania, West Virginia, and Ohio. It formed during the Pre-Illinoian ice epoch when the retreat of the ice sheet northwards blocked the drainage of these valleys to the north. The lake formed south of the ice front continued to rise until it was able to breach a low divide near New Martinsville, West Virginia. The overflow was the beginning of the process which created the modern Ohio River valley.

Lake Monongahela
Lake Monongahela during its most expansive period. Based on the map of John A. Harper; 1997.
Lake Monongahela
LocationPennsylvania, Ohio & West Virginia
Coordinates39.97°N 80°W / 39.97; -80
Lake typeformer lake
EtymologyMonongahela River
Primary inflowsLaurentide Ice Sheet
Primary outflowsOhio River
Basin countriesUnited States
First flooded900,000 years before present
Max. length122 mi (196 km)
Max. width365 mi (587 km)
212 mi (341 km)
Residence time170,000 years in existence
Surface elevationc. 1,160 ft (354 m)
ReferencesLake Monongahela: Anatomy of an Immense Ice Age Pond; John A. Harper; Bureau of Topographic and Geologic Survey; 1997.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.