USGS/SLU Regional Moment Solution
12/12/11 10:32:03.92 Epicenter: 24.006 121.665 MW 4.4 USGS/SLU REGIONAL MOMENT TENSOR Depth 34 No. of sta: 12 Moment Tensor; Scale 10**15 Nm Mrr= 1.69 Mtt=-2.04 Mpp= 0.36 Mrt= 0.53 Mrp= 2.07 Mtp=-3.20 Principal axes: T Val= 3.72 Plg=39 Azm=245 N 0.97 47 36 P -4.69 15 142 Best Double Couple:Mo=4.3*10**15 NP1:Strike= 19 Dip=75 Slip= 40 NP2: 276 51 160
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.