M 6.5 - 25 km NW of Atka, Alaska

Slight damage (VI) on Atka. Felt strongly on Adak. Depth from broadband displacement seismograms. FAULT PLANE SOLUTION: P-Waves NP1:Strike=160 Dip=82 Slip=5 NP2:Strike=69 Dip=85 Slip=172 Principal Axes: (T) Plg=9 Azm=24 (P) Plg=2 Azm=115 Comment: The focal mechanism is moderately well controlled and corresponds to strike-slip faulting with a small reverse component. The preferred fault plane is not determined. MOMENT TENSOR SOLUTION Dep 42 No. of sta: 19 Moment Tensor; Scale 10**25 d-cm Mrr=0.65 Mtt=2.52 Mff=-3.18 Mrt=2.73 Mrf=0.88 Mtf=-2.38 Principal axes: (T) Val=4.75 Plg=31 Azm=13 (N) Val=-0.06 Plg=52 Azm=234 (P) Val=-4.70 Plg=20 Azm=116 Best Double Couple:Mo=4.7*10**25 NP1:Strike=158 Dip=52 Slip=9 NP2:Strike=62 Dip=83 Slip=142 CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 16S, 38C M.W.: 13S, 27C Centroid Location: Origin Time 16:20:30.6 0.2 Lat 52.53N 0.02 Lon 174.70W 0.03 Dep 15.0 FIX Half-duration 7.4 Moment Tensor; Scale 10**25 D-CM Mrr=0.07 0.07 Mtt=4.60 0.07 Mff=-4.68 0.06 Mrt=3.26 0.34 Mrf=1.87 0.26 Mtf=-4.46 0.06 Principal Axes: (T) Val=7.23 Plg=20 Azm=18 (N) Val=0.43 Plg=60 Azm=250 (P) Val=-7.66 Plg=22 Azm=116 Best Double Couple:Mo=7.4*10**25 NP1:Strike=156 Dip=60 Slip=-2 NP2:Strike=247 Dip=88 Slip=-150

Maximum observed Modified Mercalli Intensity (MMI) VI