The Mediterranean Filled Quickly?

It took me a many years (and many hours with a John McPhee book in my lap) to realize how slow things happen in geologic time. Ranges like the Rocky Mountains jut upward over millions of years, and bodies of water like Lake Superior fill rifts in techtonic plates over thousands of years.

The slower-than-glacial pace of the earth's changes is why I was surprised to hear recently that the Mediteranean sea filled up in a mere two years!

5.33 million years ago, water began to surge at a speed one thousand times greater than the Amazon river flows today over a ridge that once separated the Mediterranean basin from the Atlantic Ocean at the spot we now call the Strait of Gibralter. Water gushed down the gradual slope on the basin side, filling the rocky depression with 10m of water daily.

Geologists found evidence for this massive flood under the Strait of Gibraltar, in earth drilled for the Africa-Europe tunnel project. There lies a u-shaped channel of loose sediment in the seafloor. Daniel Garcia-Castellanos suggests that a u-shape channel suggests flooding instead of a more gradual river flow which would create a v-shaped channel.

Garcia-Castellanos modeled this flow, according to the depth, width, and height of the channel, and estimates the flood could have lasted between 2 months and 2 years. So sudden!

The model for Mediterranean Sea flooding is still in tentative theory stage, so I bet scientists will continue to look for other evidence of rapid erosion--perhaps at the bottom of the sea basin?