USGS Centroid Moment Solution
13/02/09 14:16:09.01 Epicenter: 1.166 -77.384 MW 6.9 USGS CENTROID MOMENT TENSOR 13/02/09 14:16:30.29 Centroid: 1.506 -76.491 Depth 119 No. of sta:136 Moment Tensor; Scale 10**19 Nm Mrr=-0.09 Mtt=-0.47 Mpp= 0.56 Mrt=-0.96 Mrp=-1.03 Mtp= 3.01 Principal axes: T Val= 3.63 Plg=21 Azm=130 N -0.61 69 306 P -3.01 1 40 Best Double Couple:Mo=3.3*10**19 NP1:Strike=267 Dip=77 Slip= 16 NP2: 173 74 166
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.