USGS Body-Wave Moment Tensor Solution
NORTHERN SUMATRA, INDONESIA
13/07/02 07:37:02.15 Epicenter: 4.654 96.662 MW 6.0 USGS MOMENT TENSOR SOLUTION Depth 8 No. of sta: 55 Moment Tensor; Scale 10**18 Nm Mrr=-0.01 Mtt=-1.25 Mpp= 1.26 Mrt=-0.11 Mrp= 0.28 Mtp=-0.36 Principal axes: T Val= 1.37 Plg=12 Azm=262 N -0.07 78 97 P -1.30 3 352 Best Double Couple:Mo=1.3*10**18 NP1:Strike=306 Dip=84 Slip= 169 NP2: 38 79 6
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.