USGS/SLU Regional Moment Solution
13/03/01 07:50:23.07 Epicenter: 42.562 -111.089 MW 3.9 USGS/SLU REGIONAL MOMENT TENSOR Depth 10 No. of sta: 49 Moment Tensor; Scale 10**14 Nm Mrr=-5.06 Mtt=-0.72 Mpp= 5.77 Mrt=-0.25 Mrp=-5.30 Mtp=-0.84 Principal axes: T Val= 7.99 Plg=22 Azm= 85 N -0.72 6 178 P -7.27 67 282 Best Double Couple:Mo=7.7*10**14 NP1:Strike= 0 Dip=67 Slip= -83 NP2: 163 24 -106
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.