USGS Centroid Moment Solution
COSTA RICA
12/09/05 14:42:07.55 Epicenter: 9.996 -85.318 MW 7.6 USGS CENTROID MOMENT TENSOR 12/09/05 14:42:35.40 Centroid: 9.972 -85.163 Depth 35 No. of sta: 156 Moment Tensor; Scale 10**20 Nm Mrr= 1.93 Mtt=-1.23 Mpp=-0.70 Mrt= 1.79 Mrp=-1.16 Mtp= 0.79 Principal axes: T Val= 2.90 Plg=66 Azm= 32 N -0.14 1 124 P -2.76 24 215 Best Double Couple:Mo=2.8*10**20 NP1:Strike=124 Dip=69 Slip= 89 NP2: 307 21 93
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.
