GRA bulk density, magnetic susceptibility, natural gamma-ray (NGR) emission, and P-wave velocity were measured with the MST on whole-core sections recovered from Site 1089 (Table T17). Color reflectance and resistivity were measured on the working half of all split APC cores using the Oregon State University Split Core Analysis Track (OSU-SCAT) (see "Explanatory Notes" chapter). Color reflectance was also measured with the Minolta CM-2002 spectrophotometer on cores from Hole 1089B (Table T17). Other physical properties measurements conducted on discrete samples included moisture, density, and P-wave velocity. Measured parameters were initial wet bulk mass (Mb), dry mass (Md), and dry volume (Vd). Velocity was measured on split-core sections using the P-wave velocity sensor 3 (PWS3).
P-wave velocity, GRA bulk density, magnetic susceptibility, and NGR were determined every 2 cm for Holes 1089A and 1089B (down to Core 177-1089B-15H). Sampling time was 4 s at every point. Time constraints were such that only magnetic susceptibility and GRA density were recorded on the other holes and cores, except Section 177-1089C-18H-3 where the P-wave logger (PWL) was turned on again. There is considerable cyclicity in the GRA bulk density record, with an overall increasing trend downhole as a result of compaction. There is also a step to greater values around 140 mbsf that is particularly apparent in Holes 1089B and 1089C. The agreement is good between discrete-sample densities (determined using the moisture and density [MAD] method) and GRA densities (Figs. F26, F27). On average, one sample was taken per core section for MAD determination in Holes 1089B and 1089C. Volume magnetic susceptibility shows considerable cyclicity with values ranging between 2 × 10-5 and 15 × 10-5 SI units. Both the frequency of the cyclicity (periods of 120-40 k.y.) and average values show an overall increasing trend downhole (Fig. F26). NGR variations generally correspond to the variations in magnetic susceptibility (Fig. F26). The downhole increase that is apparent in GRA density and magnetic susceptibility, however, is not apparent in the NGR record.
P-wave velocities measured with the PWS3 velocimeter were slightly greater on average than those logged by the PWL of the MST. (Fig. F26). PWS3 velocities increased slightly downhole from an average of ~1510 at the top to 1545 m/s at the bottom. There is also an overall increase downhole in the PWL data between 0 and 70 mcd. A bimodal distribution develops between 70 and 120 mcd, where measured values shift between 1425 and 1475 m/s. This is not apparent in the PWS3 data. Below 120 mcd, the PWL velocities appear to continue the trend of the lower distribution that developed between 70 and 120 mcd, resulting in a net increase in the difference between PWL and PWS3 velocities. The reason for this is uncertain, but it is probably an artifact of the quality of the contact between the core liner and the sediment or a wrong threshold setting (see "Explanatory Notes" chapter). This may result in a lower signal level and the second rather than first wavelet being auto-picked by the PWL, which leads to longer traveltimes and lower velocities being recorded.
Porosity determined gravimetrically
on discrete samples (by the MAD method) ranged from 82% at the top of the hole to 62% at
the bottom of the hole (Fig. F26). Resistivity
measurements at Site 1089 are lowest at the top and gradually increase downhole, and
values range from 0.1 to ~0.8 
m,
with discrete spikes exceeding 1.0 m (Fig. F26). The formation factor was
calculated for the resistivity measurements (see "Explanatory Notes"
chapter) and was plotted against porosity determined from discrete samples from the same
depth (Fig. F28A). A power-curve fit to this plot
yields the a and m parameters in the modified Archie equation
F = a
-m,
where F is the formation
factor, is the porosity
fraction, a is a proportionality constant, and m is a constant that is a function of the
particular lithology. The equation of the curve fit can then be used to estimate porosity
from the high-resolution resistivity measurements provided by the OSU-SCAT. The ability of
this estimate to reproduce the measured porosities is shown in Figure F28B, where the resistivity measurements that were
used to determine a and m are used to calculate porosity. There is, in general, good
agreement with a mean difference of 3% between measured and estimated porosity values. The
agreement could be further improved by considering each major lithologic unit separately.
Closely spaced (4 to 6 cm) measurements of diffuse spectral reflectance at Site 1089 exhibit rhythmic variations with a tendency toward lower maximum reflectance values below 100-150 mcd (Fig. F29). Values in the red reflectance band (650-750 nm) range from ~10% to ~45%. Minimum reflectance values in the red and near-infrared (nIR) bands exhibit little trend below 40 mcd but increase up section above that depth. This change is not observed in the blue reflectance band and is possibly related to the oxidation of shallow, surface sediments relative to those below. As at Site 1088, reflectance in the blue, red, and nIR bands is highly correlated. Likewise, reflectance values are well correlated with GRA density (see "Chronostratigraphy," p. 8).
Color reflectance measurements were obtained with the Minolta CM-2002 spectrophotometer on Cores 177-1089B-7H through 11H for comparison with data obtained with the OSU-SCAT reflectance instrument. CM-2002 measurements were made at 5-cm spacing through the "granular material cover-set" on cores covered with Glad plastic wrap. Although the cover-set may alter the shape of the observed reflectance spectra, this compromise seemed reasonable to prevent the possibility of contaminating the instrument's integrating sphere or of scratching the glass lens of the cover-set. Care was taken to ensure that the CM-2002 was calibrated between cores to ensure minimal core-to-core offsets.
Blue (450-550 nm) and red (650-750 nm OSU-SCAT; 650-700 nm Minolta) reflectance measurements generated by the instruments are, to first order, similar (Fig. F30). More detailed comparison of the full reflectance measurements from the two instruments will be conducted postcruise.
A total of 99 thermal conductivity measurements on core sections from Site 1089 ranged from 0.79 to 1.05 W/(m·K) (Table T18, also in ASCII format in the TABLES directory). The average value is 0.92 W/(m·K), and the distribution of the values is shown in Figure F31. There is a reasonably good linear correlation between bulk density and thermal conductivity measurements (interpolated values) in the uppermost 100 mbsf, but deeper intervals do not show any significant correlation.
Three temperature measurement attempts were made at Site 1089, one in bottom water about 20 m above the seafloor, and two in sediment with Cores 177-1089-4H and 7H (Fig. F32; Table T19). The seafloor measurement yielded a bottom-water temperature of 1.1°± 0.1°C. The sediment data were too noisy to be interpreted as a result of considerable heave that created random frictional heat when the probe was stationed in the hole. Heat flow could therefore not be determined at this site.
