code: def get_depth_term(self, C, rup):
          
          if rup.ztor > 100.0:
              return C["bSLH"] * 100.0
          else:
              return C["bSLH"] * rup.ztor
docs: Returns depth term (dependent on top of rupture depth) as given
          in equations 1
  
          Note that there is a ztor cap of 100 km that is introduced in the
          Fortran code but not mentioned in the original paper!