USGS WPhase Moment Solution

NORTH ISLAND OF NEW ZEALAND

12/12/07 18:19: 8

Epicenter: -38.333  176.043
MW 6.3

USGS/WPHASE CENTROID MOMENT TENSOR
12/12/07 18:19: 8.00
Centroid:  -38.233  176.171
Depth 170         No. of sta: 45
Moment Tensor;   Scale 10**18 Nm
  Mrr= 1.06       Mtt= 0.20
  Mpp=-1.25       Mrt= 3.13
  Mrp= 0.18       Mtp=-1.46
 Principal axes:
  T  Val=  3.92  Plg=46  Azm= 13
  N     = -0.63      27      250
  P     = -3.29      30      142

Best Double Couple:Mo=3.6*10**18
 NP1:Strike=181 Dip=29 Slip=  18
 NP2:        75     81       118

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.