USGS/SLU Regional Moment Solution
12/11/27 19:06:21.58 Epicenter: 40.745 19.634 MW 3.9 USGS/SLU REGIONAL MOMENT TENSOR Depth 20 No. of sta: 14 Moment Tensor; Scale 10**14 Nm Mrr=-1.56 Mtt= 2.26 Mpp=-0.70 Mrt= 3.75 Mrp=-6.25 Mtp=-1.40 Principal axes: T Val= 7.62 Plg=37 Azm= 44 N 0.12 15 146 P -7.74 49 253 Best Double Couple:Mo=7.7*10**14 NP1:Strike=327 Dip=84 Slip= -75 NP2: 79 16 -158
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.