Two M>8 earthquakes (15/11/2006 and 13/01/2007) in Kurils Islands within less than 60 days and less than 100 km
Two distinct focal mechanisms ! Two distinct aftershocks distribution patterns !
Two large events (Mw 8.3 and Mw 8.2) distant of less than 100 km occurred in the Kurils Islands within less than 60 days (on 15/11/2006 at 11:14 GMT and on 13/01/2007 at 04:23 GMT).
The 2 events present :
- Different focal mechanisms: Normal fault on 13/01 and Thrust on 15/11.
- Very different aftershocks distribution patterns with almost twice as many aftershocks after the 15/11 event than after the 13/01 event. A lack of large event for after the 13/01 event.
- A distribution pattern which covers a 200km wide area for the 15/11 event whereas the aftershocks are mainly distributed on one side of the trench for the 13/01 event. While for the November 15th event, the aftershock epicenters were spread over an area of roughly 400x200km encompassing both plates, the first 3 days of aftershock activity for the January 13th event are spread over a more limited region (300x100km) and seem to be localised in their vast majority within the subducted plate.
Mw 8.2 on 13/01/2007
Mw 8.3 on 15/11/2006
From 15/11 to 20/11, the EMSC recorded more than 134 aftershocks of magnitude greater than 4.0, 79 with M>5 (see day by day distribution). The aftershocks are mainly distributed North-East of the Main shock on a distance of about 300 km (see Figure below).
An earthquake sequence has been observed in the same region from 26/09 to 04/10/2006 (6-7 weeks before the main shock).
Seismic activity in the Kurils Islands from 26/09 to 04/10/2006 (6-7 weeks before the main shock)
Events distribution from 26/09 to 04/10/2006
Information about the tsunamiFor more information about the tsunami that has been generated by this event, see :
The effects of this earthquake were a surprise at the Crescent City Harbor (California) on 15/11/2006 afternoon, after a surge wave caused "extensive damage," according to the California Office of Emergency Services. An OES alert said the 6-foot surge wave at Crescent City came in at around 30 mph. Visit the University of Southern California web site for more information.