USGS Body-Wave Moment Tensor Solution
NEAR EAST COAST OF HONSHU, JAPAN
11/04/07 14:32:44.60 Epicenter: 38.255 141.632 MW 7.1 USGS MOMENT TENSOR SOLUTION Depth 50 No. of sta: 111 Moment Tensor; Scale 10**19 Nm Mrr= 5.97 Mtt=-2.39 Mpp=-3.58 Mrt=-0.32 Mrp=-1.43 Mtp=-0.96 Principal axes: T Val= 6.18 Plg=82 Azm= 99 N -1.88 3 207 P -4.31 8 298 Best Double Couple:Mo=5.5*10**19 NP1:Strike= 31 Dip=37 Slip= 94 NP2: 205 53 87
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 form 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.