USGS Centroid Moment Solution
OFF W. COAST OF N. ISLAND, N.Z.
12/07/03 10:36:15.97 Epicenter: -39.976 173.693 MW 6.3 USGS CENTROID MOMENT TENSOR 12/07/03 10:36:47.00 Centroid: -39.167 173.676 Depth 267 No. of sta: 13 Moment Tensor; Scale 10**18 Nm Mrr= 0.34 Mtt= 0.93 Mpp=-1.27 Mrt= 2.18 Mrp=-1.55 Mtp= 0.74 Principal axes: T Val= 2.89 Plg=43 Azm= 10 N 0.20 25 127 P -3.10 36 237 Best Double Couple:Mo=3.0*10**18 NP1:Strike= 26 Dip=26 Slip= 170 NP2: 125 86 65
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.
