An ultra-high resolution marine record from the Gulf of Alaska during the last deglacial period

The North Pacific has likely played an important role in global climate variability. However, the magnitude and timing of climate response in this region is poorly constrained. Here we present data from an ultra-high resolution (~1cm/yr) marine sediment core from the Gulf of Alaska spanning the last deglacial period. Core EW0408-66JC is located on the Alaskan margin (58°N, 137°W), at a depth of 426m. Data collected on this core includes faunal and lithic counts, stable isotope measurements, and radiocarbon dates on both benthic and planktonic foraminifera. This multi-proxy approach provides insight on the timing of deglaciation, water mass properties and paleoecology. The benthic/planktonic age differences vary throughout the deglacial period, with maximum differences occurring during the mid-Younger Dryas (YD). This is concurrent with a minimum in planktonic δ13C and may indicate the expansion of old waters into the high-latitude North Pacific. Diagenetic barite crystals and iron pyrite framboids are present throughout the YD period, indicating a shift to low oxygen conditions during this time. The uppermost portion of this core captures the initial transition from the YD into the Holocene, indicated by a shift in faunal assemblage and a disappearance of pyrite. These results suggest that rapid shifts in both ocean circulation and stratification occurred in the Gulf of Alaska during the last deglacial period.