北西太平洋における炭素循環に関連した古海洋研究の現状

概要

論文の詳細を見る
Variations in the ocean's carbon system through time are of fundamental interest for chemical oceanography and paleoclimatology. Since the North Pacific (NP) contributes more than 25% of the world ocean volume, variations in the NP Ocean system may have profound effects in redistributing carbon within the world ocean, which eventually causes the variations of the ocean-atmosphere carbon flux. However, paleoceanographic studies in the high-latitude NP have less progressed than those in the North Atlantic. A benthic δ^<13>C record from high latitude NP sediments suggests that the ventilation of the deep Pacific would have actually been decreased during glacial times. In contrast, seismic reflection profiles and occurrence of oxidized brown clays suggest enhanced advection of Antarctic bottom water or formation of deep water locally in the NP during glacial periods. Benthic δ^<13>C patterns at Pacific intermediate water core sites are contradictory with regard to changes in the intermediate circulation of the Pacific. The NP benthic δ^<13>C record suggests that the NP deep water were continuously more corrosive to carbonate than deep waters in the North Atlantic. However, carbonate deposition at the deep NP core sites was enhanced during glacial times. This paradox may be explained by an increase in alkalinity in the global NP deep water.
日本地球化学会の論文
1997-08-04