USGS Body-Wave Moment Tensor Solution
OFF EAST COAST OF HONSHU, JAPAN
12/12/09 02:34:18.71 Epicenter: 37.766 143.591 MW 5.1 USGS MOMENT TENSOR SOLUTION Depth 6 No. of sta: 11 Moment Tensor; Scale 10**16 Nm Mrr=-5.03 Mtt=-0.65 Mpp= 5.68 Mrt= 1.51 Mrp= 2.44 Mtp= 1.30 Principal axes: T Val= 6.56 Plg=13 Azm=283 N -0.71 11 16 P -5.85 73 143 Best Double Couple:Mo=6.2*10**16 NP1:Strike=202 Dip=59 Slip= -78 NP2: 359 33 -110
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.