This region, where Pacific plate is being forced under the North American plate, is one of the world's most active seismic zones. In 1957, magnitude 8.6 Andreanof Islands earthquake ruptured a ~600 km-long portion of the plate boundary in the central Aleutian Islands. The current sequence of earthquakes is located above the ruptured portion of the megathrust. The earthquake depths are shallow, indicating that they occurred in the crust of the North American plate and not along the plate interface.

Based on the waveform modelling, the mainshock and largest aftershocks are characterized by normal faulting on a NNW-SSE oriented fault plane.