The 23 June 2014 Mw 7.9 Rat Islands archipelago, Alaska, intermediate depth earthquake

On 23 June 2014, the largest intermediate depth earthquake (M-w 7.9) of the last 100 years ruptured within the subducting Pacific plate about 100 km below the Rat Islands archipelago of the Western Aleutian Islands, Alaska. The unusual faulting orientation, strike = 206 degrees, dip = 24 degrees, and rake = -14 degrees, is possibly related to curvature of the underthrust slab and high obliquity of the relative plate motions. The first similar to 15 s of the rupture generated relatively weak seismic waves, followed by strong energy release for the next 25 s. The seismic moment is 1.0 x 10(21) Nm, and slip of up to similar to 10m is concentrated within a 50 km x 50 km region. The radiated energy is 1.1 to 2.7 x 10(16) J, assuming attenuation t* of 0.4 to 0.7 s. This type of intraplate faulting can be very damaging for populated regions above subduction zones such as Japan, Taiwan, Chile, and Indonesia.