USGS Body-Wave Moment Tensor Solution
12/10/08 11:43:35.30 Epicenter: -4.515 129.081 MW 6.1 USGS MOMENT TENSOR SOLUTION Depth 10 No. of sta: 25 Moment Tensor; Scale 10**18 Nm Mrr= 1.52 Mtt=-0.78 Mpp=-0.74 Mrt=-0.65 Mrp=-0.14 Mtp= 0.75 Principal axes: T Val= 1.74 Plg=71 Azm=154 N -0.18 17 309 P -1.56 7 42 Best Double Couple:Mo=1.6*10**18 NP1:Strike=297 Dip=55 Slip= 69 NP2: 150 41 117
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.