Fig. 1.Example calculations
of the maximum Coulomb failure stress change along optimally oriented right-lateral
(black) and left-lateral (white) planes, as a function of the regional stress
direction. The regional stress magnitude is 100 bars uniaxial compression. The
example fault is 70 km long and 12.5 km deep with 5 m of tapered slip and a
stress drop of 85 bars. The coefficient of friction (
=0.4)
controls the angle between the right and left lateral planes and the influence
of the normal stress on the Coulomb stress. Near the fault, the optimal planes
are rotated because the failure stress change is nearly as large as the regional
stress.