USGS WPhase Moment Solution

NORTHERN SUMATRA, INDONESIA

13/ 1/10 13:47:3.00

Epicenter:   4.753   95.132
MW 5.7

USGS/WPHASE CENTROID MOMENT TENSOR
13/ 1/10 13:47: 3.00
Centroid:    4.353   95.333
Depth  45         No. of sta: 43
Moment Tensor;   Scale 10**17 Nm
  Mrr= 2.15       Mtt=-1.33
  Mpp=-0.82       Mrt= 3.11
  Mrp=-2.67       Mtp= 0.90
 Principal axes:
  T  Val=  4.67  Plg=58  Azm= 42
  N     = -0.15       1      309
  P     = -4.52      31      219

Best Double Couple:Mo=4.6*10**17
 NP1:Strike=304 Dip=13 Slip=  84
 NP2:       130     76        91

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.