USGS Body-Wave Moment Tensor Solution
11/09/03 22:55:36.96 Epicenter: -20.619 169.714 MW 7.0 USGS MOMENT TENSOR SOLUTION Depth 143 No. of sta: 51 Moment Tensor; Scale 10**19 Nm Mrr= 1.63 Mtt=-0.03 Mpp=-1.61 Mrt= 2.72 Mrp=-1.79 Mtp= 1.66 Principal axes: T Val= 3.69 Plg=56 Azm= 11 N 0.55 18 130 P -4.24 28 230 Best Double Couple:Mo=4.0*10**19 NP1:Strike=359 Dip=24 Slip= 142 NP2: 125 75 71
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.