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

Moment Tensor Solution
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.

Moment Tensor Solution

Details on the W-phase inversion algorithm.