The studied site, ODP Site 1017 (34°32´N, 121°6´W, water depth = 955.6 m), is located ~60 km to the west of Point Conception, on the upper part of the continental slope called the Santa Lucia Slope (Fig. 1). The Santa Lucia Slope faces southwest with its shallow end bounded by the Santa Lucia Bank. According to Hickey (1979), the present surface water at the site is under the influence of the California Current from the north and a northward branch of the Southern California Countercurrent from the southeast. The latter is continuous with the Davidson Current flowing from the south during winter when there is no upwelling. The present bottom water at this site is probably under the influence of California Undercurrent from the south, which is marked by high temperature, salinity, and phosphate, and low dissolved oxygen (Hickey, 1979). The core depth of the California Undercurrent off Point Conception is 200-300 m, but can be deeper than 500 m during spring (Hickey, 1979). Its flow speed is generally slow (<10 cm/s), but a maximum speed sometimes exceeds 22 cm/s. It is also possible that the bottom water is influenced by NPIW as discussed by van Green et al. (1996). The site is located within the lower part of present OMZ. This position is ideal to monitor changes in intensity and/or depth of the OMZ through time. The site is also close (~70 km northwest) to the entrance of Santa Barbara Basin, an ideal location to test the hypothesis that bottom-water oxygenation of Santa Barbara Basin has been driven by changes in intermediate water source in the North Pacific (Kennett and Ingram, 1995; Behl and Kennett, 1996).