USGS WPhase Moment Solution

ALASKA PENINSULA

12/12/01  8:00:57

Epicenter:  58.533 -154.180
MW 5.3

USGS/WPHASE CENTROID MOMENT TENSOR
12/12/01 08:00:57.00
Centroid:   58.433 -153.796
Depth 100         No. of sta: 33
Moment Tensor;   Scale 10**16 Nm
  Mrr= 3.07       Mtt=-8.54
  Mpp= 5.47       Mrt= 6.93
  Mrp= 5.12       Mtp= 1.84
 Principal axes:
  T  Val= 11.32  Plg=42  Azm=293
  N     =  0.46      37       66
  P     =-11.79      25      177

Best Double Couple:Mo=1.2*10**17
 NP1:Strike=317 Dip=39 Slip= 164
 NP2:        59     80        52

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.