USGS Body-Wave Moment Tensor Solution
12/06/01 05:07:01.65 Epicenter: -77.025 -148.850 MW 5.5 USGS MOMENT TENSOR SOLUTION Depth 12 No. of sta: 28 Moment Tensor; Scale 10**17 Nm Mrr=-1.64 Mtt= 2.08 Mpp=-0.44 Mrt= 0.96 Mrp= 0.63 Mtp= 0.32 Principal axes: T Val= 2.39 Plg=15 Azm=350 N -0.34 16 256 P -2.06 68 120 Best Double Couple:Mo=2.2*10**17 NP1:Strike=247 Dip=62 Slip=-108 NP2: 102 33 -60
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.