The paleoclimatic response of the Southern Californian Margin to the rapid climate change of the last 60 ka: A regional overview

High-resolution planktonic foraminiferal census and stable isotope data from a core transect (ODP Site 1017, 893 and 1014) demonstrate remarkable similarities along the Southern California Margin during the last glacial (60–10 ka BP). Modern analog technique and δ18O derived sea surface temperatures (SST) demonstrate SST shifts were regionally expressed supporting the hypothesis that the relative strength of local surface ocean currents affected the advection of subpolar and subtropical water into the region. Divergent alkenone SST records suggest the flux of planktonic organisms shifted seasonally during the last glacial in response to changing environmental conditions. When considered as seasonal SST reconstructions, summer/oligotrophic surface ocean conditions appear to have a muted response to orbital and millennial-scale climate change compared to the surface ocean during high nutrient/winter conditions.