(Dan Garratt)

external image mediterranean-sea.jpg

Much like a mattress springs back into shape after you get off it, the Earth’s crust moves upwards when sea levels fall. Known as isostasy, this phenomenon explains how the Mediterranean Sea was sealed off from the Atlantic Ocean five million years ago. This ‘dam’ would remain in place for 170,000 years. Much like today, the rate of evaporation in the Mediterranean Sea five million years ago greatly exceeded the incoming flow of water. As no more water was introduced via the Straits of Gibraltar, the water evaporated and the Mediterranean Sea dried up completely.After being separated for 170,000 years, the Mediterranean Sea and the Atlantic Ocean were once again connected. Govers believes that the movement of the Earth’s crust played a crucial role. The African Plate subducts under the Eurasian Plate beneath Gibraltar and the weight of the subducting edge of the African Plate may have pulled the entire region downwards. Govers submits CT scans of the inner layers of the Earth’s crust and measurements of gravitational forces as evidence: both the scans and the measurements indicate the presence of a heavy mass up to 400 kilometres beneath the area.

So how’d it happen?
It happened because of the climate. In the Mediterranean the climate is very hot. This heat energy is transferred into the sea, resulting in the water particles to gain more energy and ‘bounce’ up. This ‘bouncing’ causes evaporation as the particles escape from the sea. As the Med' was cut off from the Atlantic, there was no way of the sea gaining enouigh water for it to stay at the same level. As the evaportaion rate was so high, and there was little rain, the mediterrarean