USGS Body-Wave Moment Tensor Solution
12/08/11 12:23:17.88 Epicenter: 38.322 46.888 MW 6.3 USGS MOMENT TENSOR SOLUTION Depth 3 No. of sta: 82 Moment Tensor; Scale 10**18 Nm Mrr= 0.20 Mtt= 0.58 Mpp=-0.78 Mrt=-0.87 Mrp=-0.39 Mtp=-3.84 Principal axes: T Val= 3.85 Plg= 7 Azm=219 N 0.32 77 99 P -4.17 11 311 Best Double Couple:Mo=4.0*10**18 NP1:Strike= 85 Dip=87 Slip=-167 NP2: 355 77 -3
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.