USGS WPhase Moment Solution
OFF EAST COAST OF HONSHU, JAPAN
12/10/01 22:21:45 Epicenter: 39.852 143.046 MW 6.1 USGS/WPHASE CENTROID MOMENT TENSOR 12/10/01 22:21:45.00 Centroid: 39.852 143.046 Depth 19 No. of sta: 32 Moment Tensor; Scale 10**18 Nm Mrr= 0.54 Mtt=-0.11 Mpp=-0.43 Mrt= 0.52 Mrp= 1.43 Mtp=-0.08 Principal axes: T Val= 1.65 Plg=53 Azm=291 N = -0.10 1 199 P = -1.55 36 108 Best Double Couple:Mo=1.6*10**18 NP1:Strike=191 Dip= 9 Slip= 81 NP2: 20 81 91
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.
