2006 M6.4 Fox Islands Earthquake

Mainshock and Aftershocks: 

The Alaska Earthquake Center located a strong earthquake that occurred on Tuesday, May 9, 2006 at 6:42 pm local time (May 10, 2:42 am UTC) in the Fox Islands region of Alaska  (red star on the above map). AEIC located about 130 aftershocks through the end of May (open circles). The largest aftershock of magnitude 5.3 occurred on May 9 at 9:07 pm local time (May 10, 5:07 am UTC, white star). Majority of the aftershocks (~80 total) occurred within the first 24 hours of the mainshock. Due to the sparse seismic station coverage in the region, the smallest located afterschoks have magnitudes of ~2.0.

Felt Reports: 

The mainshock was felt strongly in Nikolski and Unalaska (Internet Community Intensity Map). No damage was reported.

Tectonic Setting: 

The earthquake occurred on the convergent boundary between the subducting Pacific and overriding North American crustal plates. This region, where the two plates are being forced directly into one another, is one of the world's most active seismic zones. Over one hundred earthquakes of magnitude seven or larger have occurred along this boundary in the past hundred years. The 1957 Mw 8.6 Andreanof Islands earthquake ruptured a ~600 km-long portion of the plate boundary in central Aleutian Islands. The current sequence of earthquakes is located within the eastern segment of the 1957 rupture zone.