USGS Body-Wave Moment Tensor Solution
SANTA CRUZ ISLANDS
13/02/09 05:32:08.28 Epicenter: -10.919 166.000 MW 5.5 USGS MOMENT TENSOR SOLUTION Depth 9 No. of sta: 35 Moment Tensor; Scale 10**17 Nm Mrr=-0.87 Mtt= 2.28 Mpp=-1.41 Mrt=-0.62 Mrp=-0.48 Mtp=-0.51 Principal axes: T Val= 2.44 Plg=10 Azm=186 N -0.61 56 82 P -1.83 32 282 Best Double Couple:Mo=2.2*10**17 NP1:Strike=319 Dip=60 Slip= -17 NP2: 58 75 -149
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.