USGS WPhase Moment Solution

SOUTHWEST INDIAN RIDGE

13/04/02 14:34:55

Epicenter: -40.380   45.288
MW 5.9

USGS/WPHASE CENTROID MOMENT TENSOR
13/04/02 14:34:55.00
Centroid:  -40.480   44.894
Depth  11         No. of sta: 38
Moment Tensor;   Scale 10**17 Nm
  Mrr=-5.25       Mtt= 5.63
  Mpp=-0.38       Mrt=-2.35
  Mrp=-5.03       Mtp= 3.00
 Principal axes:
  T  Val=  8.26  Plg=18  Azm=150
  N     =  0.15      24       51
  P     = -8.41      58      273

Best Double Couple:Mo=8.3*10**17
 NP1:Strike=274 Dip=34 Slip= -42
 NP2:        41     68      -116

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.