동해 코아 퇴적물에서 빙기-간빙기간 SST변화와 식물플랑크톤 군집변화

Abstract

A high-resolution organic geochemical study of core E09-08 was conducted to evaluate glacial-interglacial climatic and oceanic changes over the last 500 kiloyears (kyr). The analysis revealed distinct fluctuations during glacial-interglacial periods. In particular, the alkenone-based sea surface temperature (SST) showed typical glacial-interglacial variation, implying glacial-interglacial scale climatic changes in the East Sea. The SST ranged from 8 to 24°C during marine isotope stages (MIS) 8 and 9. n-Alkanes, terrestrial plant biomarkers, also showed distinct glacial-interglacial fluctuations. In general, the total concentration of n-alkanes increased during glacial periods and it decreased during interglacial periods with varying magnitude (Fig. 1). Also average chain length (ACL) shows glacial-interglacial fluctuation, glacial increase and interglacial decrease except for MIS12, generally correspond to the pattern of total n-alkane fluctuation. Therefore, climate changes during glacial-interglacial period can alter the n-alkanes concentration. Additionally, marine algal-derived biomarkers of Cholesterol, Brassicasterol and B-sitosterol exhibited distinct fluctuation that were especially larger during MIS6 and 8, suggesting that phytoplankton productivity has fluctuated in accordance with climatic changes over the last 500 kyr. This implies that phytoplankton productivity has been fluctuated in accordance withl periods. In particular, the alkenone-based sea surface temperature (SST) showed typical glacial-interglacial variation, implying glacial-interglacial scale climatic changes in the East Sea. The SST ranged from 8 to 24°C during marine isotope stages (MIS) 8 and 9. n-Alkanes, terrestrial plant biomarkers, also showed distinct glacial-interglacial fluctuations. In general, the total concentration of n-alkanes increased during glacial periods and it decreased during interglacial periods with varying magnitude (Fig. 1). Also average chain length (ACL) shows glacial-interglacial fluctuation, glacial increase and interglacial decrease except for MIS12, generally correspond to the pattern of total n-alkane fluctuation. Therefore, climate changes during glacial-interglacial period can alter the n-alkanes concentration. Additionally, marine algal-derived biomarkers of Cholesterol, Brassicasterol and B-sitosterol exhibited distinct fluctuation that were especially larger during MIS6 and 8, suggesting that phytoplankton productivity has fluctuated in accordance with climatic changes over the last 500 kyr. This implies that phytoplankton productivity has been fluctuated in accordance with