USGS Body-Wave Moment Tensor Solution

NORTHERN MID-ATLANTIC RIDGE

12/10/04 23:14:56.74

Epicenter:  17.456  -46.510
MW 5.4

USGS MOMENT TENSOR SOLUTION
Depth   4         No. of sta: 37
Moment Tensor;   Scale 10**17 Nm
  Mrr=-0.74       Mtt=-0.16
  Mpp= 0.90       Mrt= 0.49
  Mrp= 1.36       Mtp=-0.58
 Principal axes:
  T  Val=  1.71  Plg=27  Azm=260
  N        0.11      25        4
  P       -1.82      52      130

Best Double Couple:Mo=1.8*10**17
 NP1:Strike=190 Dip=77 Slip= -64
 NP2:       306     29      -151

Moment Tensor Solution
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.

Moment Tensor Solution