USGS WPhase Moment Solution

OFF W COAST OF NORTHERN SUMATRA

12/ 1/10 18:37:1.00

Epicenter:   2.396   93.175
MW 7.2

USGS/WPHASE CENTROID MOMENT TENSOR
12/ 1/10 18:37: 1.00
Centroid:    2.496   92.974
Depth  19         No. of sta: 96
Moment Tensor;   Scale 10**19 Nm
  Mrr= 0.26       Mtt=-2.86
  Mpp= 2.60       Mrt= 0.07
  Mrp=-1.87       Mtp=-6.29
 Principal axes:
  T  Val=  7.11  Plg=13  Azm= 57
  N     =  0.01      74      206
  P     = -7.12       7      325

Best Double Couple:Mo=7.1*10**19
 NP1:Strike=101 Dip=75 Slip= 176
 NP2:       192     86        15

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.