Comparison of Oceanic 14C Data with Those of GEOSECS: Vertical Profiles in 1973 (GEOSECS) and in 1980 at (30 Degrees N, 170 Degrees E) in the Northwestern Pacific Ocean

Abstract

The vertical profile of radiocarbon at (30 degrees N, 170 degrees E) measured in 1980 was compared with the GEOSECS data measured in 1973. 14C was extracted from 200L of sea water, converted to C2H2, and analyzed with a gas proportional counter. Our profile and that of GEOSECS were in good agreement below 700m depth without systematic deviation of Delta-14C values between both measurements. On the other hand, a Delta-14C increase was observed above 700m depth, reflecting the transient addition, in 6.6 years, of bomb 14C to the intermediate layer from the atmosphere.