Japan Earthquake Shifted Sea Floor 50 Metres

Plate shift led to 9.0 earthquake that flattened Japan's southeastern coast.

The earthquake that sent a tsunami crashing across Japan's eastern coast did more than just obliterate entire towns – it shifted the sea floor of the Pacific Ocean by 50 metres. A new analysis of the seismic changes wrought by the 9.0 March 11 earthquake shows that Okhotsk tectonic plate, upon which Japan and eastern Russia sit, moved 50 metres east-southeast toward the Japan Trench, a deep rift where the Okhotsk and Pacific plates meet. The Okhotsk plate also moved about 16 metres upward. While the floor at the trench shifted by about half a football field, the ground closer to shore only shifted by about five metres, meaning the sea floor actually stretched by some 45 metres. Those changes shook much of Japan's most populated regions and sent forth a tsunami that killed more than 15,000 people. It also destroyed the Fukushima nuclear power plant that still hasn't fully recovered.