USGS/SLU Regional Moment Solution
12/12/06 17:48:15.92 Epicenter: 36.940 23.111 MW 4.4 USGS/SLU REGIONAL MOMENT TENSOR Depth 8 No. of sta: 12 Moment Tensor; Scale 10**15 Nm Mrr=-3.70 Mtt= 0.06 Mpp= 3.64 Mrt=-0.13 Mrp= 1.22 Mtp=-1.86 Principal axes: T Val= 4.60 Plg= 8 Azm=248 N -0.69 6 338 P -3.91 80 106 Best Double Couple:Mo=4.3*10**15 NP1:Strike=330 Dip=37 Slip=-100 NP2: 163 53 -82
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.