USGS/SLU Regional Moment Solution
12/10/12 21:26:34.42 Epicenter: -23.675 -67.936 MW 4.6 USGS/SLU REGIONAL MOMENT TENSOR Depth 115 No. of sta: 14 Moment Tensor; Scale 10**15 Nm Mrr=-5.06 Mtt=-2.59 Mpp= 7.65 Mrt= 3.34 Mrp=-5.35 Mtp=-0.21 Principal axes: T Val= 9.76 Plg=21 Azm= 83 N -1.16 23 343 P -8.60 58 211 Best Double Couple:Mo=9.2*10**15 NP1:Strike=208 Dip=32 Slip= -41 NP2: 334 70 -115
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.