USGS Body-Wave Moment Tensor Solution
12/05/12 23:28:42.57 Epicenter: 38.662 70.410 MW 5.6 USGS MOMENT TENSOR SOLUTION Depth 14 No. of sta: 93 Moment Tensor; Scale 10**17 Nm Mrr= 0.77 Mtt=-1.06 Mpp= 0.30 Mrt=-0.14 Mrp=-2.81 Mtp=-1.85 Principal axes: T Val= 3.66 Plg=42 Azm= 70 N -0.34 35 199 P -3.32 28 311 Best Double Couple:Mo=3.5*10**17 NP1:Strike= 92 Dip=36 Slip= 167 NP2: 193 82 55
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.