USGS Body-Wave Moment Tensor Solution
NORTHERN SUMATRA, INDONESIA
11/09/05 17:55:11.46 Epicenter: 2.996 97.986 MW 6.7 USGS MOMENT TENSOR SOLUTION Depth 90 No. of sta: 68 Moment Tensor; Scale 10**19 Nm Mrr=-0.12 Mtt= 0.23 Mpp=-0.10 Mrt= 0.78 Mrp=-1.01 Mtp=-0.25 Principal axes: T Val= 1.37 Plg=40 Azm= 44 N -0.13 10 142 P -1.24 48 244 Best Double Couple:Mo=1.3*10**19 NP1:Strike= 76 Dip=11 Slip=-157 NP2: 323 86 -80
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.