USGS Body-Wave Moment Tensor Solution
12/11/30 11:20:39.48 Epicenter: -18.869 -175.539 MW 5.7 USGS MOMENT TENSOR SOLUTION Depth 228 No. of sta: 38 Moment Tensor; Scale 10**17 Nm Mrr=-2.82 Mtt= 1.11 Mpp= 1.71 Mrt=-1.60 Mrp=-1.98 Mtp= 1.29 Principal axes: T Val= 3.73 Plg=21 Azm=129 N 0.08 0 219 P -3.81 69 309 Best Double Couple:Mo=3.8*10**17 NP1:Strike=218 Dip=24 Slip= -91 NP2: 39 66 -90
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.