USGS WPhase Moment Solution

SANTA CRUZ ISLANDS

13/ 1/31  3:33:49.00

Epicenter: -10.669  166.375
MW 6.1

USGS/WPHASE CENTROID MOMENT TENSOR
13/ 1/31  3:33:49.00
Centroid:  -10.269  166.274
Depth  15         No. of sta: 52
Moment Tensor;   Scale 10**18 Nm
  Mrr=-1.41       Mtt= 0.37
  Mpp= 1.03       Mrt= 0.19
  Mrp= 0.31       Mtp=-0.97
 Principal axes:
  T  Val=  1.74  Plg= 2  Azm=234
  N     = -0.23      15      325
  P     = -1.51      74      135

Best Double Couple:Mo=1.6*10**18
 NP1:Strike=309 Dip=44 Slip=-112
 NP2:       159     50       -69

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.