At Site 1095, we tied MCS and borehole data using the velocities derived in situ with the velocity check shots and the vertical seismic profile. This is because this velocity estimation uses the same wavelength and source as the one used in seismic reflection profiling (GI guns). This choice is strengthened by the good agreement between in situ velocity and velocity measured in the laboratory with high-frequency transducers. Figure F11 illustrates the velocity trend and its correlation to the seismic units described by Rebesco et al. (1997) and the lithostratigraphic units described on board (Shipboard Scientific Party, 1999b). The vertical seismic profile is tied to MCS seismics in Figure F12 according to position and strength of major reflectors. As shown in Figure F11, the uncertainty in correlation increases dramatically below the bottom of hole because of the extrapolation downward of the velocity trend. For the illustration in Figure F12, we chose the polynomial interpolation. Equations for both polynomial and linear interpolations are provided. A summary of the main tie points is illustrated in Figure F13. A list of tie points with values in two-way traveltime and depth units is additionally provided in Table T5.
The synthetic seismic trace obtained with the same methodology as described by the Shipboard Scientific Party (1999a) is compared with a compressed stacked section of seismic profile I95-135 around Site 1095 in Figure F14 The rather monotonous character of the seismic section in terms of frequencies and amplitudes prevents a firm statement about the quality of the match between synthetic and seismic traces.
At Site 1096, in the absence of in situ velocity measurements we produced a diagram similar to that shown in Figure F11 using the interval velocities obtained with the tomographic inversion of traveltimes. The resulting velocity trend and its correlation to the seismic units described by Rebesco et al. (1997) and the lithostratigraphic units described on board (Shipboard Scientific Party, 1999c) are presented in Figure F15. A list of tie points with values in two-way traveltime and meters below seafloor units is additionally provided in Table T5.
The synthetic seismic trace obtained with the same methodology as described by the Shipboard Scientific Party (1999a) is compared with a compressed stacked section of profile I95-135 around Site 1096 in Figure F16. The synthetic trace satisfactorily reproduces the alternation of packages of low- and high-amplitude reflectors as well as the decreasing frequency at the base of the hole.
At Site 1101, the traveltime-depth relationship is derived from the laboratory PWS3 velocity data (Fig. F17). A list of tie points with values in two-way traveltime and depth units is additionally provided in Table T5.