USGS Body-Wave Moment Tensor Solution
SANTA CRUZ ISLANDS
12/01/09 04:07:16.59 Epicenter: -10.577 165.178 MW 6.3 USGS MOMENT TENSOR SOLUTION Depth 28 No. of sta: 41 Moment Tensor; Scale 10**18 Nm Mrr= 1.91 Mtt=-3.28 Mpp= 1.37 Mrt= 0.92 Mrp=-1.83 Mtp=-0.46 Principal axes: T Val= 3.63 Plg=49 Azm= 77 N -0.19 40 276 P -3.44 9 178 Best Double Couple:Mo=3.5*10**18 NP1:Strike=231 Dip=50 Slip= 34 NP2: 118 65 135
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.