Imagine a dry basin where the Mediterranean now sits. 5.6 million years ago the Mediterranean was closed off from the Atlantic Ocean by tectonic uplift, and its waters gradually evaporated, leaving behind tell-tale deposits of evaporate minerals and creating what geologists call the Messinian salinity crisis.
About 5 million years ago Atlantic waters breached the barrier at the Strait of Gibraltar creating an enormous flood. Recent modeling indicated that water may have poured into the Mediterranean basin at a rate 1,000 times the flow of today’s Amazon River, filling the basin in less than two years—a geological blink of an eye.
Source: Daniel Garcia-CAstellanos, et al, December 10, 2009 Nature.
Illustration credit: http://records.viu.ca/~earles/messinian-crisis-apr03.htm
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