USGS Centroid Moment Solution
NEAR EAST COAST OF HONSHU, JAPAN
11/04/07 14:32:44.60 Epicenter: 38.255 141.632 MW 7.1 USGS CENTROID MOMENT TENSOR 11/04/07 14:33:01.50 Centroid: 38.457 141.660 Depth 51 No. of sta: 151 Moment Tensor; Scale 10**19 Nm Mrr= 6.49 Mtt=-1.64 Mpp=-4.85 Mrt=-1.02 Mrp=-0.36 Mtp=-1.76 Principal axes: T Val= 6.61 Plg=83 Azm=174 N -0.94 6 25 P -5.67 4 294 Best Double Couple:Mo=6.1*10**19 NP1:Strike= 18 Dip=42 Slip= 81 NP2: 210 49 98
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.