List of rivers that have reversed direction

From Wikipedia, the free encyclopedia

A number of rivers are known to have reversed the direction of their flow, either permanently or temporarily, in response to geological activity, weather events, climate change, or direct human intervention.

Permanent reversals[]

Construction of the Chicago Sanitary and Ship Canal
River Original outlet Current outlet Continent Date of reversal Cause of reversal References
Amazon River Pacific Ocean Atlantic Ocean South America Cretaceous period Formation of Andes Mountains [1]
Chicago River Lake Michigan Mississippi River North America 1900 Construction of Chicago Sanitary and Ship Canal [1]

Temporary reversals[]

The Reversing Falls of the Saint John River, flowing upriver

Intermittent reversals[]

Hurricane storm surges often cause temporary reversals of coastal rivers.[1]

River Outlet Continent Date of reversal Cause of reversal References
Chicago River[a] Mississippi River North America 2017 and others[b] Storm surge [2]
Mississippi River Gulf of Mexico North America 1812 Tectonic uplift caused by New Madrid earthquakes [3]
2005 Storm surge from Hurricane Katrina [1]
2012 Storm surge from Hurricane Isaac [1][4]
2021 Storm surge from Hurricane Ida [5]
  1. ^ These reversals represent a return to the Chicago River's original natural outlet in Lake Michigan.
  2. ^ Reversals of the Chicago River have been increasing in frequency in association with global warming, and may soon occur at least once each year.[2]

Regular reversals[]

All tidal sections of rivers reverse their flow with the tide about twice a day, by definition. The Hudson and the Saint John River are just examples.[6]

River Outlet Continent Frequency of reversal Cause of reversal References
Hudson River Upper New York Bay North America semidiurnal Tide in Upper New York Bay [6]
Petexbatún River Pasión River Central America annual Winter rain flooding of the Pasión River [7]
Qiantang River Hangzhou Bay Asia annually around August 15th Tidal bore in Hangzhou Bay [8]
Saint John River (Reversing Falls) Bay of Fundy North America semidiurnal Tide in the Bay of Fundy [9]
Tonlé Sap River Mekong River Asia annual Monsoon flooding of the Mekong River [10]

See also[]

  • Stream capture, in which a stream or river is diverted from its own bed, and flows instead down a neighboring channel

References[]

  1. ^ a b c d e Borneman, Elizabeth (November 24, 2014). "Rivers that Flow Backwards". Geo Lounge. Retrieved 18 March 2019.
  2. ^ a b "How Climate Change Is Making This River Run Backwards". EcoWatch. Natural Resources Defense Council. June 4, 2017. Retrieved 19 March 2019.
  3. ^ Soniak, Matt (January 25, 2013). "Has a U.S. River Run Backwards Before?". Mental Floss. Retrieved 18 March 2019.
  4. ^ "Mississippi River Flows Backwards Due to Isaac". USGS Newsroom. United States Geological Survey. August 29, 2012. Retrieved 19 March 2019.
  5. ^ "Hurricane Ida Is So Strong It Reversed the Mississippi's Current". interestingengineering.com. 2021-08-30. Retrieved 2021-08-30.
  6. ^ a b "The Hudson Estuary: A River That Flows Two Ways". New York State Department of Environmental Conservation. Retrieved 19 March 2019.
  7. ^ The Petexbatún eco-system (in Spanish) Retrieved 30 January 2021.
  8. ^ The Bore Tides of the Qiantang River Retrieved 30 January 2021.
  9. ^ "Reversing Falls". New-Brunswick.net. Retrieved 18 March 2019.
  10. ^ Jennings, Ken (February 2, 2015). "Why the Tonle Sap River Is Unlike Any Other River in the World". Condé Nast Traveler. Retrieved 18 March 2019.
Retrieved from ""