Continental divide
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A continental divide is a line of elevated terrain which forms a border between two watersheds such that water falling on one side of the line eventually travels to one ocean or body of water, and water on the other side travels to another, generally on the opposite side of the continent. Since the exact border between bodies of water is usually not clearly defined, the continental divide is not always definite for any continent (The International Hydrographic Organization's publication Limits of Oceans and Seas defines exact boundaries of oceans, but it is not universally recognized). Moreover, some rivers empty into deserts or inland seas, and thus do not end up in the oceans.
Examples
- North America has a clear continental divide, sometimes called the Great Divide, running from the Seward Peninsula in Alaska, through western Canada along the crest of the Rocky Mountains to New Mexico. From there it follows the crest of Mexico's Sierra Madre Occidental. East of this divide, rainfall drains into the Atlantic Ocean or Arctic Ocean, and west into the Pacific Ocean.Missing image
NorthAmericaDivides.gifContinental Divides in North America - The Eastern Continental Divide or Eastern Divide runs from northern Pennsylvania down the Appalachian Mountains to the tip of Florida, dividing the Atlantic from the Gulf of Mexico. The city of Atlanta sits atop this divide.
- Other continental divides in North America are the Northern Divide and the St. Lawrence Seaway Divide.
- In South America, the Continental Divide lies along the Andes.
- Australia has less distinct ocean boundaries around it, and less prominent mountain ranges, making it hard to define a single divide.
- It is similarly difficult to distinguish Europe and Asia's continental divides because of the large number of distinct bodies of water into which their rainfall drains (for example, the Mediterranean Sea and its various lobes, the Atlantic Ocean, the North Sea, the Baltic Sea, the Arctic Ocean and the Black Sea with Europe).
Every continent except for Antarctica has a continental divide.
See also
External links
- Continental Divide Trail Alliance (http://www.cdtrail.org/)
- nationalatlas.gov (http://nationalatlas.gov/articles/geology/a_continentalDiv.html)
- Divide.pdf (http://www.state.nd.us/ndgs/Newsletter/NLS03/pdf/Divide.pdf) - Continental Divides in North Dakota and North America by Mark A. Gonzalez. Excellent article on America's other continental divides.
- Map of drainage basins in Canada (http://atlas.gc.ca/site/english/maps/reference/national/drainbasins/referencemap_image_view)