Biogenic sedimentation beneath the California Current System for the past 30 kyr and its paleoceanographic significance

Enhanced marine productivity off western North America during warm climate intervals of the past 52 k.y.

“…Carbonate content in the core is inversely correlated with C org content (Fig. 3C), reaching maximum values during cool glacial and stadial climate intervals, as is typically seen in the California Current (e.g., Gardner et al, 1997). This suggests greater carbonate dissolution during organic-rich interstadial events.…”

“…While the C org record from the Santa Barbara Basin lacks interstadial peaks, interstadial maxima in the concentration of the upwelling-related planktonic foraminifera G. bulloides provide evidence of increased production within the basin during warm periods (Hendy and Kennett, 2000). Likewise, high C org accumulation during warm interstadial events is observed in cores throughout the Oregon and California margins (Gardner et al, 1997;Mix et al, 1999). Such evidence, combined with our open-margin results from the Baja California site, suggests that warm interstadial events, including present conditions, were associated with elevated productivity over much of the northeast Pacific.…”

Evidence for Millennial-Scale Climate Change During Marine Isotope Stages 2 and 3 at Little Lake, Western Oregon, U.S.A.

“…In the Northeast Pacific, cores from the Santa Barbara Basin and the central California and southern Oregon margins show variations in sea-surface temperatures and oceanic circulation (Behl and Kennett, 1996;Gardner et al, 1997;Hendy and Kennett, 1999;Lund and Mix, 1998). Millennial-scale variations in these regions have primarily been associated with shifts in the position and strength of the Eastern Pacific subtropical high, the Aleutian low, and the jet stream.…”

“…Low values of the bioturbation index reflect intervals that correlate with warmer sea-surface temperatures (Hendy and Kennett, 1999). signal implies little change in the position of the jet stream. In addition, strong upwelling along the central California margin suggests that the jet stream and subtropical high were close to their present positions (Gardner et al, 1997). An alternative explanation invokes variations in the strength of the subtropical high and the jet stream, without significant shifts in their position.…”

Paleolimnology and Paleoclimate Studies in Upper Klamath Lake, Oregon

“…The findings contained in the papers in this volume have important implications for comparisons between lacustrine records in the western United States and marine records from the eastern Pacific Ocean (e.g., Gardner et al 1997;Herbert et al 2001). The Upper Klamath Lake record is also a contribution toward transects that document latitudinal variations in climate along the west coast of the Americas (e.g., Markgraf 1995;Bradbury et al 2001).…”