USGS WPhase Moment Solution
TONGA
12/ 9/22 6:58:26.00 Epicenter: -20.820 -174.184 MW 5.6 USGS/WPHASE CENTROID MOMENT TENSOR 12/ 9/22 6:58:26.00 Centroid: -20.720 -173.970 Depth 15 No. of sta: 22 Moment Tensor; Scale 10**17 Nm Mrr= 1.59 Mtt=-0.32 Mpp=-1.27 Mrt= 0.93 Mrp= 1.88 Mtp=-0.60 Principal axes: T Val= 2.64 Plg=63 Azm=296 N = -0.03 0 206 P = -2.61 26 116 Best Double Couple:Mo=2.6*10**17 NP1:Strike=206 Dip=18 Slip= 89 NP2: 26 72 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.
