The quake was located near the Kuril Islands, 1030 miles northeast of Tokyo. The magnitude 8.3 quake (incredibly strong) was followed by no less than 4 aftershocks that registered over 6.0 on the Richter Scale and 7 aftershocks that registered between 5.0 and 6.0. Any one of those aftershocks on their own would be considered a significant earthquake. Fortunately, it is currently believed that the displacement along the seafloor was mostly horizontal and not vertical, as major vertical displacement would have likely resulted in catastrophic tsunamis that could impact anywhere from Japan to Russia to Alaska and the Pacific Northwest all the way down to California. There is thousands of miles of open ocean between the location of the quake and the western US. We are lucky.
Link to the earthquake location at Google Maps. You may wish to zoom out to see the region better.