Ocean Currents and Climate

Ocean Zones

The bottom of Lake Como is 200 meters below sea level, and the reason is that the Mediterranean Sea once evaporated almost completely.Around 5.5 million years ago, tectonics sealed the Strait of Gibraltar. Cut off from the Atlantic, the Mediterranean dried into a salt desert more than a kilometer below today's coastlines. Geologists call it the Messinian Salinity Crisis.With the sea gone, every river flowing south off the Alps suddenly had a kilometer of extra elevation to fall. They responded t

About a quarter of the ocean's surface is a desert. Hundreds of miles of open water with almost no food in it. So when a big ship crosses one of these empty stretches, it becomes the only interesting thing for miles, and fish start trailing along behind it.Biologists have studied this for decades. Any floating object out there, a log, a clump of seaweed, a drifting coconut, a stray piece of trash, a whole ship, ends up working like a magnet for fish. To something living in all that emptiness, an