USGS/SLU Regional Moment Solution
NORTHERN SUMATRA, INDONESIA
13/01/21 22:22:54.00 Epicenter: 4.961 96.083 MW 6.1 USGS/SLU REGIONAL MOMENT TENSOR Depth 12 No. of sta: 15 Moment Tensor; Scale 10**18 Nm Mrr=-0.01 Mtt=-1.43 Mpp= 1.44 Mrt= 0.12 Mrp= 0.66 Mtp= 0.02 Principal axes: T Val= 1.70 Plg=21 Azm=271 N -0.25 68 77 P -1.44 5 179 Best Double Couple:Mo=1.6*10**18 NP1:Strike= 47 Dip=79 Slip= 19 NP2: 313 72 168
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.