Earth's surface is composed of two kinds of crust, continental and oceanic. Most continental crust is over 3 billion years old, while virtually all oceanic crust is less than 180 million years old. Oceanic crust is young because it is...

Seafloor spreading occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics. Earlier...

The Tyrrhenian Sea is that small ocean basin in the Mediterranean that looks as though it's forever being kicked around by Italy. It kicks back now and then with earthquakes and volcanoes, so it's known to be a geologically active area. But scientists...

Scientists have discovered a new ultra-slow class of ocean ridge involved in seafloor spreading. Investigations in the far south Atlantic and Indian Oceans and the seafloor beneath the Arctic icecap have found that for large regions there, the seafloor splits apart by pulling up...