relatively high pore pressures along the base of the prism thus, maintaining its narrow

taper.

 To investigate the combined effect of both vertical hydrofracture and the

 decollement with the bulk permeability-effective stress relationship the two parameters

 were combined. The maximum X* (0.87) estimated from the combined simulation is

 similar to the maximum X* estimated from bulk permeability-effective stress relationship

 in the decollement and in the underthrust (Table 4-3).

 Table 4-3. Summary of simulation runs with the estimated values of maximum k* (X*max)
 in the underthrust and the decollement. The location of the *.max is given seaward from
 the arcward end of the model during 2.7 million years of prism growth.
Run Unit log (p Vertical kd Underthrust D6collement
 (ko) Hydro- (m2) .m locati ** .m location
 fracture on
 (m2)
Base Run Turbidites -20 5.25 NA NA 0.93 15.0 0.94 10.8
 Hemipelagics -22 8.44
Bekins et al. Turbidites -22 8.44 NA 105 0.64 39.0 0.64 0.40
(1995) Hemipelagics -22 8.44
Vertical Turbidites -20 5.25 10-" NA 0.93 15.0 0.94 10.8
hydrofractur Hemipelagics -22 8.44
e
Varying kd Turbidites -20 5.25 1013 kbulk- 0.87 10.0 0.87 12.0
 Hemipelagics -22 8.44 av
Vertical Turbidites -20 5.25 1013 kbulk- 0.87 10.0 0.87 10.8
hydrofractur Hemipelagics -22 8.44 av
e+ varying kd

 However, the combined simulation indicate a slight variation in the X* profile

 closer to the deformation front relative to those estimated using only the bulk

 permeability-effective stress relationship in the decollement (Figure 4-4). The combined

 simulation predicts slightly higher values (by 0.02) of k -28 km seaward from the

 arcward end (Figure 4-4). This slightly high X* may represent the minor effect of vertical

 hydrofracture. The observed sudden increase in the X* profiles closer to the deformation

 of both in the bulk permeability-effective stress simulation and the combined simulation

 may suggest a possible transient response. However, these transient events probably