USGS Body-Wave Moment Tensor Solution
NIAS REGION, INDONESIA
13/04/05 17:35:30.78 Epicenter: 0.281 98.666 MW 5.0 USGS MOMENT TENSOR SOLUTION Depth 35 No. of sta: 20 Moment Tensor; Scale 10**16 Nm Mrr= 3.71 Mtt=-0.66 Mpp=-3.05 Mrt= 1.67 Mrp=-0.80 Mtp= 2.06 Principal axes: T Val= 4.27 Plg=72 Azm= 3 N 0.25 15 145 P -4.52 11 238 Best Double Couple:Mo=4.4*10**16 NP1:Strike=346 Dip=37 Slip= 115 NP2: 135 57 72
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.