A closely spaced conductivity-temperature-depth/hydrographic section w
as conducted off the east coast of Japan in July 1992. The southeastwa
rd section crossed the Japan Trench and the Kuroshio in the vicinity o
f the Kashima 1 seamount. Vertical sections of temperature, salinity,
density, oxygen, and nutrients are discussed in conjunction with the m
ovement and interleaving of water masses. Complicated vertical and hor
izontal mixings of water masses are inferred from the temperature and
salinity relationships. Mixing processes are patchy and not continuous
beneath the front. Warm, salty water found beneath the Kuroshio may r
esult from upward mixing of water from intermediate depths. The main a
xis of the Kuroshio, indicated by the 14-degrees-C isotherm at 200 m,
is at 35.7-degrees-N, 142.6-degrees-E, about 20 km from the north wall
surface thermal front. Geostrophic speeds exceed 170 cm s-1 at the su
rface; volume transport through the section is 81 X 10(6) m3 s-1.