USGS WPhase Moment Solution

IZU ISLANDS, JAPAN REGION

12/ 1/ 1  5:27:54.00

Epicenter:  31.416  138.155
MW 6.8

USGS/WPHASE CENTROID MOMENT TENSOR
12/ 1/ 1  5:27:54.00
Centroid:   31.516  138.272
Depth 350         No. of sta: 75
Moment Tensor;   Scale 10**19 Nm
  Mrr=-0.36       Mtt=-0.06
  Mpp= 0.42       Mrt=-0.33
  Mrp=-1.63       Mtp=-0.51
 Principal axes:
  T  Val=  1.72  Plg=36  Azm= 81
  N     =  0.11      18      186
  P     = -1.83      47      297

Best Double Couple:Mo=1.8*10**19
 NP1:Strike=114 Dip=19 Slip=-163
 NP2:         8     84       -71

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.