USGS Body-Wave Moment Tensor Solution
NORTH OF ASCENSION ISLAND
13/01/12 21:50:17.93 Epicenter: 0.061 -17.036 MW 5.1 USGS MOMENT TENSOR SOLUTION Depth 4 No. of sta: 12 Moment Tensor; Scale 10**16 Nm Mrr=-3.92 Mtt= 2.01 Mpp= 1.91 Mrt=-0.23 Mrp= 2.30 Mtp=-3.05 Principal axes: T Val= 5.36 Plg=11 Azm=227 N -0.54 20 321 P -4.82 67 110 Best Double Couple:Mo=5.1*10**16 NP1:Strike=154 Dip=59 Slip= -66 NP2: 293 38 -124
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.