USGS Body-Wave Moment Tensor Solution
SANTIAGO DEL ESTERO, ARGENTINA
11/09/02 13:47:11.63 Epicenter: -28.430 -63.125 MW 6.7 USGS MOMENT TENSOR SOLUTION Depth 589 No. of sta: 52 Moment Tensor; Scale 10**19 Nm Mrr=-0.92 Mtt= 0.66 Mpp= 0.26 Mrt=-0.26 Mrp= 1.18 Mtp= 0.22 Principal axes: T Val= 1.00 Plg=30 Azm=280 N 0.70 12 183 P -1.70 57 75 Best Double Couple:Mo=1.5*10**19 NP1:Strike=180 Dip=76 Slip=-102 NP2: 42 18 -50
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.