USGS/SLU Regional Moment Solution
12/11/10 17:08:12.93 Epicenter: 37.124 -82.954 MW 4.2 USGS/SLU REGIONAL MOMENT TENSOR Depth 13 No. of sta: 50 Moment Tensor; Scale 10**15 Nm Mrr=-0.66 Mtt= 1.70 Mpp=-1.04 Mrt=-0.80 Mrp= 0.58 Mtp= 1.29 Principal axes: T Val= 2.31 Plg=11 Azm=161 N -0.24 56 267 P -2.07 32 64 Best Double Couple:Mo=2.2*10**15 NP1:Strike=109 Dip=76 Slip= -31 NP2: 207 60 -164
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.