USGS Body-Wave Moment Tensor Solution
SOUTHWEST INDIAN RIDGE
13/04/02 14:34:55.36 Epicenter: -40.443 45.303 MW 5.8 USGS MOMENT TENSOR SOLUTION Depth 3 No. of sta: 25 Moment Tensor; Scale 10**17 Nm Mrr=-6.22 Mtt= 5.49 Mpp= 0.73 Mrt= 2.99 Mrp=-0.89 Mtp= 3.19 Principal axes: T Val= 7.48 Plg=10 Azm=336 N -0.20 17 69 P -7.28 70 218 Best Double Couple:Mo=7.4*10**17 NP1:Strike= 46 Dip=38 Slip=-119 NP2: 261 57 -69
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.