USGS Body-Wave Moment Tensor Solution
ANDREANOF ISLANDS, ALEUTIAN IS.
13/08/30 16:25:02.76 Epicenter: 51.610 -175.361 MW 6.9 USGS MOMENT TENSOR SOLUTION Depth 36 No. of sta:122 Moment Tensor; Scale 10**19 Nm Mrr= 1.70 Mtt=-1.66 Mpp=-0.04 Mrt= 1.62 Mrp= 0.63 Mtp=-0.32 Principal axes: T Val= 2.44 Plg=67 Azm=331 N -0.01 5 74 P -2.43 23 166 Best Double Couple:Mo=2.4*10**19 NP1:Strike= 72 Dip=68 Slip= 84 NP2: 267 23 104
The figure above shows a visual representation of the style of faulting (focal mechanism) derived from the estimated moment tensor. Shaded areas show quadrants of the focal sphere in which the P-wave first-motions are away from the source, and unshaded areas show quadrants in which the P-wave first-motions are toward the source. The dots represent the axis of maximum compressional strain (in black, called the "P-axis") and the axis of maximum extensional strain (in white, called the "T-axis") resulting from the earthquake.