USGS WPhase Moment Solution

SOUTHEASTERN ALASKA

13/01/14 14:55:53

Epicenter:  55.158 -134.547
MW 5.5

USGS/WPHASE CENTROID MOMENT TENSOR
13/01/14 14:55:53.00
Centroid:   55.158 -134.547
Depth  11         No. of sta: 42
Moment Tensor;   Scale 10**17 Nm
  Mrr= 0.03       Mtt=-1.44
  Mpp= 1.41       Mrt= 1.12
  Mrp= 0.38       Mtp= 1.17
 Principal axes:
  T  Val=  2.12  Plg=21  Azm=295
  N     =  0.14      57       63
  P     = -2.26      23      195

Best Double Couple:Mo=2.2*10**17
 NP1:Strike=336 Dip=57 Slip=-178
 NP2:       245     89       -32

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.