Table 4-1. Fluid and solid matrix properties used for numerical simulations.
Parameter Value
Fluid compressibility [Pa-1] 4.40E-10
Fluid density [kg m-3] 1035
Fluid specific heat [J kg-lOC-1] 4180
Fluid thermal conductivity [J s-1 m-1 "C-1] 0.7
Solid grain density [kg m-3] 2650
Solid grain specific heat [J kg-1oC- '] 1000
Solid grain thermal conductivity [J s-1 m-1 C-1] 3.0
Sedimentation and Loading Rates
Sedimentation seaward of the deformation front and loading due to the over-riding
prism were applied separately in two different phases (Table 4-2). Sedimentation rates
for phase one were calculated based on the biostratigraphy of Site 672. During phase
one, the incoming sediment column was built using 25 time steps of 2,680,000 years.
The average initial sedimentation rate for each unit was based on the initial thickness of
that unit and its corresponding deposition time as provided in the biostratigraphy of Site
672. The initial thickness of each unit (i.e., the thickness of the sediment layer prior to
consolidation) was calculated based on an initial porosity of 0.70 and 0.60 for
hemipelagics and turbidites respectively. Final porosity was estimated based on bulk
density data from Leg 171A, Site 1044 (Shipboard Scientific Party, 1998). Porosity was
estimated using a solid grain density of 2.65 g/cm3 and a fluid density of 1.035 g/cm3 as
used in Screaton and Ge (2000). According to Screaton and Ge (2000) the largest error
associated in this conversion is due to the presence of smectite interlayer water, which
will overestimate porosity values. During phase two, prism-thickening rates were
calculated using prism thickness at Site 671 and a convergence rate of 2 cm/yr. Because
the prism was built in segments, the number of loading steps used in phase two varied
from 10 to 40 with a constant loading step size of 67,500 years.