USGS WPhase Moment Solution

SOUTHEAST OF LOYALTY ISLANDS

12/03/03 12:19:55

Epicenter: -22.157  170.317
MW 6.6

USGS/WPHASE CENTROID MOMENT TENSOR
12/03/03 12:19:55.00
Centroid:  -22.057  170.101
Depth  23         No. of sta: 26
Moment Tensor;   Scale 10**18 Nm
  Mrr=-0.12       Mtt=-3.63
  Mpp= 3.74       Mrt= 2.34
  Mrp=-2.15       Mtp= 7.52
 Principal axes:
  T  Val=  8.47  Plg= 4  Azm=121
  N     =  0.90      70       18
  P     = -9.37      18      212

Best Double Couple:Mo=9.0*10**18
 NP1:Strike=255 Dip=74 Slip= -10
 NP2:       348     80      -163

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.