USGS Body-Wave Moment Tensor Solution
SANTA CRUZ ISLANDS
13/02/09 21:02:22.52 Epicenter: -10.965 165.792 MW 6.5 USGS MOMENT TENSOR SOLUTION Depth 18 No. of sta: 89 Moment Tensor; Scale 10**18 Nm Mrr=-0.75 Mtt= 3.23 Mpp=-2.48 Mrt= 0.57 Mrp= 0.96 Mtp=-6.81 Principal axes: T Val= 7.76 Plg= 0 Azm=214 N -0.56 80 306 P -7.20 10 124 Best Double Couple:Mo=7.5*10**18 NP1:Strike=168 Dip=83 Slip= -7 NP2: 259 83 -173
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.