USGS Body-Wave Moment Tensor Solution
COSTA RICA
12/09/08 20:29:31.22 Epicenter: 10.073 -85.342 MW 5.6 USGS MOMENT TENSOR SOLUTION Depth 23 No. of sta: 41 Moment Tensor; Scale 10**17 Nm Mrr= 2.42 Mtt= 0.09 Mpp=-2.52 Mrt=-0.02 Mrp= 0.38 Mtp= 2.03 Principal axes: T Val= 2.47 Plg=82 Azm=308 N 1.18 8 152 P -3.65 3 61 Best Double Couple:Mo=3.2*10**17 NP1:Strike=339 Dip=49 Slip= 100 NP2: 143 42 79
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.
