An extensive oceanographic investigation has been carried out in
the North Pacific Ocean. The purpose of this report is to present the results of
two cruises in which we participated and to report additional carbonate data
from samples collected for us in the North Pacific. These data are combined with
data from the literature to provide an overall picture of the carbonate system in
the North Pacific.
The degree of saturation of seawater with respect to calcite and aragonite was
calculated from all available data sets. Four selected cross sections, three longitudinal
and one latitudinal, and two three-dimensional graphs show that a large
volume of the North Pacific is undersaturated with respect to CaC03. The
saturation horizon generally shows a shoaling from west to east and from south
to north in the North Pacific Ocean. It was found that the lysocline is at a depth
much deeper (about 2500 m deeper) than the saturation horizon of calcite, and
several hundred meters shallower than the calcium carbonate compensation
depth. Our results appear to support the kinetic point of view on the CaC03
dissolution mechanisms. Differences in the abundance of the calcareous sediments
are explained by differences in the calcium carbonate compensation depth
