USGS WPhase Moment Solution

SANTA CRUZ ISLANDS

13/ 2/ 9 21: 2:22.00

Epicenter: -10.969  165.754
MW 6.6

USGS/WPHASE CENTROID MOMENT TENSOR
13/ 2/ 9 21: 2:22.00
Centroid:  -10.669  165.550
Depth  19         No. of sta: 42
Moment Tensor;   Scale 10**18 Nm
  Mrr=-2.56       Mtt= 5.50
  Mpp=-2.93       Mrt=-1.76
  Mrp= 3.84       Mtp=-8.64
 Principal axes:
  T  Val= 11.78  Plg=14  Azm=213
  N     = -2.55      64      335
  P     = -9.23      20      118

Best Double Couple:Mo=1.1*10**19
 NP1:Strike=257 Dip=65 Slip=-174
 NP2:       165     85       -25

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.