USGS WPhase Moment Solution

NEAR S. COAST OF WESTERN HONSHU

13/04/12 20:33:16

Epicenter:  34.413  134.827
MW 5.8

USGS/WPHASE CENTROID MOMENT TENSOR
13/04/12 20:33:16.00
Centroid:   34.313  135.069
Depth  13         No. of sta:116
Moment Tensor;   Scale 10**17 Nm
  Mrr= 5.66       Mtt=-0.67
  Mpp=-5.00       Mrt= 0.54
  Mrp=-3.55       Mtp= 0.75
 Principal axes:
  T  Val=  6.75  Plg=73  Azm= 82
  N     = -0.54       0      350
  P     = -6.21      16      260

Best Double Couple:Mo=6.5*10**17
 NP1:Strike=350 Dip=28 Slip=  89
 NP2:       171     62        90

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.