USGS Body-Wave Moment Tensor Solution
13/08/12 18:03:33.36 Epicenter: -56.515 -142.308 MW 5.7 USGS MOMENT TENSOR SOLUTION Depth 9 No. of sta: 22 Moment Tensor; Scale 10**17 Nm Mrr=-0.12 Mtt= 3.30 Mpp=-3.18 Mrt= 0.26 Mrp= 0.38 Mtp= 2.04 Principal axes: T Val= 3.92 Plg= 5 Azm=344 N -0.13 83 207 P -3.79 5 74 Best Double Couple:Mo=3.9*10**17 NP1:Strike=119 Dip=83 Slip= 0 NP2: 29 90 173
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.