USGS WPhase Moment Solution

SOUTHEASTERN ALASKA

13/01/31  9:53:43

Epicenter:  55.584 -134.745
MW 5.9

USGS/WPHASE CENTROID MOMENT TENSOR
13/01/31 09:53:43.00
Centroid:   55.384 -135.098
Depth  11         No. of sta: 82
Moment Tensor;   Scale 10**17 Nm
  Mrr=-1.74       Mtt= 3.89
  Mpp=-2.14       Mrt=-0.74
  Mrp=-2.94       Mtp= 6.62
 Principal axes:
  T  Val=  8.64  Plg=12  Azm=145
  N     = -1.40      64       27
  P     = -7.24      21      240

Best Double Couple:Mo=8.0*10**17
 NP1:Strike=281 Dip=65 Slip=  -7
 NP2:        14     84      -155

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.