USGS Body-Wave Moment Tensor Solution

SOUTHERN ALASKA

12/12/04 01:42:48.00

Epicenter:  61.230 -150.719
MW 5.7

USGS MOMENT TENSOR SOLUTION
Depth  60         No. of sta: 35
Moment Tensor;   Scale 10**17 Nm
  Mrr= 2.34       Mtt=-4.28
  Mpp= 1.95       Mrt= 0.08
  Mrp= 3.22       Mtp= 1.86
 Principal axes:
  T  Val=  5.55  Plg=45  Azm=281
  N       -0.65      44      116
  P       -4.90       7       19

Best Double Couple:Mo=5.3*10**17
 NP1:Strike=322 Dip=66 Slip= 140
 NP2:        70     54        30

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