Philippine Sea Plate
This earthquake was an intraplate earthquake greater than 50 kilometers to the east of the boundary of the Philippine Sea Plate. This earthquake was unusual in that it occurred as a result of reverse faulting within the oceanic lithosphere of the Philippine Sea Plate. There have been approximately 40 events of M6 and above over the past 40 years, within 250 km of this earthquake. Most of those earthquakes were the result of normal faulting within the shallower oceanic lithosphere rather than deeper reverse faulting like this event.