Pacific Coast of Tohoku, Honshu Island, Japan

On March 11th, 2011, an earthquake of magnitude Mw 9.0 occurred off the Pacific coast of Tohoku, Honshu Island, Japan, at 14:46 local time (05:46 UTC.) More information here. It has been followed by a series of powerful aftershocks, with 31 earthquakes of magnitude larger than 6 in 3 days.

The earthquake epicenter is located approximately 100 km off Miyagi at a depth of 22km. It was widely felt as far as Tokyo, about 400 km away. A tsunami wave was generated in the Pacific, with wave heights reported at more than 4 m high. The Yomiuri daily newspaper reports that the tsunami waves reached at least 23m according to a study by the Port and Airport Research Institute in Ofunato (Iwate prefecture).

This is the largest earthquake ever recorded in Japan, and is among the 5 largest earthquakes recorded worlwide.

Two days earlier, on March 9th, another large earthquake occurred in the same area, approximately 35 km away from the main earthquake March 11th. More information is available at the EMSC and at the USGS.