USGS Body-Wave Moment Tensor Solution
SANTA CRUZ ISLANDS
13/02/28 18:07:48.28 Epicenter: -10.922 165.963 MW 5.8 USGS MOMENT TENSOR SOLUTION Depth 37 No. of sta: 28 Moment Tensor; Scale 10**17 Nm Mrr= 7.82 Mtt=-2.32 Mpp=-5.50 Mrt=-1.19 Mrp= 0.18 Mtp= 1.03 Principal axes: T Val= 7.96 Plg=83 Azm=182 N -2.13 6 343 P -5.83 2 73 Best Double Couple:Mo=7.1*10**17 NP1:Strike=169 Dip=43 Slip= 99 NP2: 337 48 82
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.