USGS Body-Wave Moment Tensor Solution
13/03/09 14:56:29.05 Epicenter: 50.850 157.309 MW 5.8 USGS MOMENT TENSOR SOLUTION Depth 44 No. of sta:103 Moment Tensor; Scale 10**17 Nm Mrr= 7.15 Mtt=-5.15 Mpp=-2.00 Mrt= 1.83 Mrp= 1.20 Mtp=-3.20 Principal axes: T Val= 7.48 Plg=81 Azm=325 N -0.00 0 58 P -7.47 8 148 Best Double Couple:Mo=7.5*10**17 NP1:Strike= 58 Dip=54 Slip= 90 NP2: 238 37 91
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.