USGS WPhase Moment Solution

TONGA

13/ 1/27  9:59:27.00

Epicenter: -16.129 -173.284
MW 5.7

USGS/WPHASE CENTROID MOMENT TENSOR
13/ 1/27  9:59:27.00
Centroid:  -15.830 -172.659
Depth  35         No. of sta: 40
Moment Tensor;   Scale 10**17 Nm
  Mrr=-3.68       Mtt= 0.13
  Mpp= 3.54       Mrt=-0.26
  Mrp=-0.12       Mtp= 1.16
 Principal axes:
  T  Val=  3.90  Plg= 1  Azm=107
  N     = -0.21       3      197
  P     = -3.70      86      355

Best Double Couple:Mo=3.8*10**17
 NP1:Strike=194 Dip=44 Slip= -95
 NP2:        20     46       -85

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.