USGS Centroid Moment Solution
VANUATU
11/09/03 22:55:36.50 Epicenter: -20.616 169.721 MW 7.0 USGS CENTROID MOMENT TENSOR 11/09/03 22:55:54.09 Centroid: -20.834 170.010 Depth 132 No. of sta: 24 Moment Tensor; Scale 10**19 Nm Mrr= 1.13 Mtt= 1.18 Mpp=-2.32 Mrt= 3.22 Mrp=-2.27 Mtp= 1.40 Principal axes: T Val= 4.44 Plg=47 Azm= 9 N 0.37 26 131 P -4.81 31 238 Best Double Couple:Mo=4.6*10**19 NP1:Strike= 20 Dip=28 Slip= 162 NP2: 126 82 63
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.
