USGS Body-Wave Moment Tensor Solution
12/11/17 05:12:56.98 Epicenter: -18.319 -172.324 MW 5.8 USGS MOMENT TENSOR SOLUTION Depth 7 No. of sta: 86 Moment Tensor; Scale 10**17 Nm Mrr=-4.96 Mtt= 0.39 Mpp= 4.57 Mrt=-0.60 Mrp= 4.80 Mtp= 0.88 Principal axes: T Val= 6.62 Plg=22 Azm=276 N 0.44 8 182 P -7.06 66 73 Best Double Couple:Mo=6.8*10**17 NP1:Strike=179 Dip=68 Slip= -99 NP2: 22 24 -69
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.