USGS Body-Wave Moment Tensor Solution
13/01/13 21:23:26.76 Epicenter: -20.131 -69.174 MW 5.3 USGS MOMENT TENSOR SOLUTION Depth 80 No. of sta: 12 Moment Tensor; Scale 10**17 Nm Mrr=-0.65 Mtt= 0.17 Mpp= 0.48 Mrt=-0.19 Mrp=-1.09 Mtp= 0.39 Principal axes: T Val= 1.31 Plg=29 Azm=114 N 0.01 12 17 P -1.32 58 267 Best Double Couple:Mo=1.3*10**17 NP1:Strike=234 Dip=20 Slip= -51 NP2: 14 75 -103
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.