USGS Body-Wave Moment Tensor Solution
13/02/09 14:16:07.83 Epicenter: 1.134 -77.378 MW 6.9 USGS MOMENT TENSOR SOLUTION Depth 149 No. of sta: 76 Moment Tensor; Scale 10**19 Nm Mrr= 0.46 Mtt=-1.01 Mpp= 0.55 Mrt=-1.07 Mrp=-0.87 Mtp= 2.11 Principal axes: T Val= 2.79 Plg=30 Azm=127 N -0.25 59 289 P -2.53 8 32 Best Double Couple:Mo=2.7*10**19 NP1:Strike=263 Dip=75 Slip= 28 NP2: 166 63 164
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.