USGS WPhase Moment Solution

OFF COAST OF CENTRAL AMERICA

13/03/10 10:18:17

Epicenter:  12.801  -90.679
MW 5.5

USGS/WPHASE CENTROID MOMENT TENSOR
13/03/10 10:18:17.00
Centroid:   12.801  -90.781
Depth  11         No. of sta:180
Moment Tensor;   Scale 10**17 Nm
  Mrr=-2.65       Mtt= 1.83
  Mpp= 0.82       Mrt=-0.34
  Mrp=-0.14       Mtp=-0.88
 Principal axes:
  T  Val=  2.35  Plg= 2  Azm=209
  N     =  0.34       5      119
  P     = -2.69      83      325

Best Double Couple:Mo=2.5*10**17
 NP1:Strike=305 Dip=43 Slip= -81
 NP2:       114     48       -97

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.