USGS WPhase Moment Solution

GULF OF CALIFORNIA

12/10/08  6:26:22

Epicenter:  25.182 -109.622
MW 5.9

USGS/WPHASE CENTROID MOMENT TENSOR
12/10/08 06:26:22.00
Centroid:   25.382 -109.732
Depth  21         No. of sta: 25
Moment Tensor;   Scale 10**18 Nm
  Mrr=-0.09       Mtt=-0.95
  Mpp= 1.04       Mrt= 0.05
  Mrp=-0.16       Mtp=-0.17
 Principal axes:
  T  Val=  1.07  Plg= 7  Azm= 85
  N     = -0.11      81      281
  P     = -0.97       2      175

Best Double Couple:Mo=1.0*10**18
 NP1:Strike=220 Dip=83 Slip=   4
 NP2:       130     86       173

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.