The recent magnitude 9.0 earthquake hit northern Japan on Friday March 11, 2011.
Related resources:
A tsunami hit japan after the earthquake.
In Japan
The 8.9 Japan Earthquake
The Earthquake of Kobe occurred in Japan in 1995.
earthquake in ocean
Friday
East of Sendai
In march 2011
The epicenter of the earthquake was offshore, close to Sendai, Japan.
The plates moved so this can occur the earthquake.
Tectonic plates shifted, creating the earthquake.
It depends on the earthquake you are talking about. Many have occurred in Japan. The most recent is the 2011 earthquake.