USGS Body-Wave Moment Tensor Solution
13/05/11 20:46:57.93 Epicenter: -17.946 -175.096 MW 6.4 USGS MOMENT TENSOR SOLUTION Depth 238 No. of sta: 98 Moment Tensor; Scale 10**18 Nm Mrr=-3.66 Mtt= 2.19 Mpp= 1.48 Mrt=-0.36 Mrp=-2.77 Mtp= 1.53 Principal axes: T Val= 4.01 Plg=17 Azm=133 N 0.88 17 37 P -4.89 66 264 Best Double Couple:Mo=4.5*10**18 NP1:Strike=247 Dip=32 Slip= -56 NP2: 29 64 -109
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.