What If We Drained the Oceans?

Randall Munroe's What If? project received a question about draining the oceans. The original question specified a hole 20 meters in diameter for the drain. That seems big, but the draining would be too slow to even notice, especially considering the melting glaciers. But if we made the hole big enough to really drain seawater, the map of the world would start to look rather weird. Since this theoretical drain is located in the Mariana Trench, it couldn't take all the earth's water, because there are geological formations that will trap some sea water in large lakes. (via Laughing Squid)