USGS WPhase Moment Solution
TONGA
13/ 2/ 7 7:19:59.00 Epicenter: -15.586 -173.142 MW 5.8 USGS/WPHASE CENTROID MOMENT TENSOR 13/ 2/ 7 7:19:59.00 Centroid: -15.486 -172.726 Depth 11 No. of sta: 42 Moment Tensor; Scale 10**17 Nm Mrr= 5.05 Mtt=-1.08 Mpp=-3.97 Mrt= 1.06 Mrp= 5.54 Mtp=-0.65 Principal axes: T Val= 7.73 Plg=64 Azm=280 N = -0.94 0 11 P = -6.79 25 101 Best Double Couple:Mo=7.3*10**17 NP1:Strike=192 Dip=19 Slip= 91 NP2: 11 70 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.
