USGS/SLU Regional Moment Solution
13/01/06 23:22:32.08 Epicenter: 40.170 21.806 MW 3.9 USGS/SLU REGIONAL MOMENT TENSOR Depth 4 No. of sta: 16 Moment Tensor; Scale 10**14 Nm Mrr=-7.84 Mtt= 6.33 Mpp= 1.51 Mrt=-1.36 Mrp= 3.03 Mtp=-1.48 Principal axes: T Val= 7.07 Plg= 9 Azm=200 N 1.71 14 292 P -8.79 74 78 Best Double Couple:Mo=8.1*10**14 NP1:Strike=121 Dip=55 Slip= -73 NP2: 274 38 -112
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.