Map of the relation between pore-fluid pressure, coefficient of friction and reactivation angle, assuming a maximum stress difference of 200 MPa. A) Three dimensional view, with colours representing the pore fluid pressure ratio; B) a two dimensional view. Taking an angle of 30 as an example, one can see that the assumed value of 0.75 for the friction coefficient requires pore fluid pressures in the > 0.80 range. Similarly, if the angle between 1, and the fault plane is 70, a < 0.35 friction coefficient is necessary to reactivate the fault. Areas in black are outside the range 0.0 1.0.