Deep water properties near 35 degrees N, 143 degrees E, observed during the Kuroshio Extension Regional Experiment

Deep water measurements were obtained from a closely spaced conductivity-temperature-depth hydrographic section that crossed the Japan Trench and the Kuroshio in the vicinity of the Kashima 1 Seamount near 35 degrees N, 143 degrees E. Vertical sections of temperature, salinity, density, oxygen, and nutrients are discussed for water below 1000 m. At the northwestern extreme of the section the existence of a southward-flowing deep western boundary current is suggested by the silica distribution as well as by geostrophic calculations. In the vicinity of the seamount, hydrographic properties are perturbed and contrasting variabilities are found in the deep water characteristics along the section. The measurements also suggest a deep northward flow associated with the trench. Current meter observations [Hallock and Teague, 1996 ] along the section lend credence to these interpretations. These observations help piece together an overall picture of the deep and abyssal circulation of the northwest Pacific.