Maps of Seismic Intensity for Earthquake under the Southern Okhotsk Sea on August 14

Distribution of seismic intensities shows a concentric circle around an epicenter in many cases, but in this case maximum seismic intensities were observed in the areas on the Pacific side far away from the epicenter (This is often called areas of anomalous seismic intensity).
In the present case, the earthquake occurred at the deep place within the Pacific plate, and therefore this is an observable event due to an efficient transmission of seismic waves within the oceanic plate.

Japan Meteorological Agency
[Evaluation of Seismic Activities for August 2012 (September 11, 2012)]