USGS WPhase Moment Solution

TONGA

12/ 4/28 10: 8:7.00

Epicenter: -18.643 -174.725
MW 6.6

USGS/WPHASE CENTROID MOMENT TENSOR
12/ 4/28 10: 8: 7.00
Centroid:  -18.643 -174.513
Depth 140         No. of sta: 39
Moment Tensor;   Scale 10**18 Nm
  Mrr=-7.18       Mtt= 6.15
  Mpp= 1.04       Mrt= 7.07
  Mrp= 3.29       Mtp= 2.58
 Principal axes:
  T  Val= 10.63  Plg=23  Azm=336
  N     = -0.03       1      246
  P     =-10.60      66      153

Best Double Couple:Mo=1.1*10**19
 NP1:Strike= 69 Dip=21 Slip= -86
 NP2:       246     69       -91

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.