Coulomb stress changes indicate where the hazard has risen as a result of the magnitude-6.5 mainshock (red ‘stress trigger zones’) and where it has dropped (blue ‘stress shadows’). Since there are both strike-slip and tensional (‘normal’) faults in the Basin and Range province, we show two calculations. The left image shows the relative hazard for normal faults in the region, whereas the right image shows that of strike slip faults of the region.