USGS/SLU Regional Moment Solution
12/12/27 23:20:55.96 Epicenter: 38.197 21.943 MW 4.0 USGS/SLU REGIONAL MOMENT TENSOR Depth 10 No. of sta: 17 Moment Tensor; Scale 10**15 Nm Mrr=-0.84 Mtt= 0.85 Mpp=-0.01 Mrt=-0.53 Mrp= 0.52 Mtp=-0.64 Principal axes: T Val= 1.42 Plg=18 Azm=210 N -0.30 13 305 P -1.12 67 70 Best Double Couple:Mo=1.3*10**15 NP1:Strike=131 Dip=64 Slip= -75 NP2: 280 30 -118
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.