High rates of sedimentation and common planktonic and benthic foraminifera make the far northwest Pacific Ocean ideal for studying the details for glacial-interglacial climate and change. A transect of large-diameter piston and gravity cores collected from between 2300 and 4000 m water depth on Meiji Drift (NW Pacific) will be used to make the first hydrographic reconstructions of a small area in the Pacific Ocean. Defining late Quaternary hydrographic change in the North Pacific is important because it is the "end member" of modern deep circulation, but limited geochemical evidence suggests that it may not have been so during glaciation. Stable isotopes and radiocarbon in foraminifera and sediment chemistry will be used to test for evidence of young (nutrient.depleted) deep water, young intermediate water, and changes in ocean ventilation, in salinity, fertility, and in the corrosiveness of bottom waters in the glacial ocean. Results from this project will be useful for comparing with similar efforts in the Atlantic and Indian Oceans in order to understand the role of the ocean in climate change.
