资源环境科技发展态势分析平台

Climatic variations in the northeastern (NE) Pacific Ocean have been related to the strength of intermediate water-driven productivity and global ocean circulation. Productivity variations and ocean circulation during the late Quaternary may have caused changes in the intensity of the oxygen minimum zone (OMZ). To understand these changes in productivity and resultant OMZ fluctuations, we analyzed benthic foraminiferal assemblages from the Cascadia margin which reveal major faunal and ecological shifts associated with the millennial-scale climate changes during similar to 32-10 ka. The intermediate waters were highly variable during similar to 20-14 ka with increased productivity and nutrient supply to the subsurface during circa 15.5-14.5 ka. Our results suggest that suboxic environmental conditions occurred during the warm interstadials, and the Bolling-angstrom llerod event was favorable for the dysoxic species. Our results further indicate that paleoclimate variations in the northeast Pacific region were mainly driven by the Pacific Intermediate Water Current.