동해 퇴적물중에서 얻어진 유기화합물 디플로텐과 탄소동위원소: 메탄방출과 고해양에 대한 의의

Abstract

Data from the core records showed that organic compounds occurred in the two cores, showing high vertical fluctuation in the 06GHSA P6 core during the Last Glacial Maximum. The diploptene concentration ranged from 1.7 to 632.1 ng/g (average 87 ng/g) in core 06GHSA P6 and from 1.4 to 42.2 ng/g in core 06GHSA P1 (average 20.1 ng/g). An especially elevated concentration of diploptene was observed in core 06GHSA P6 during glacial periods. Carbon isotope values in the diploptene ranged from –56.33 to –60.23 per mil, suggesting that this diploptene was in part derived from methanotrophic bacteria, which decomposed methane in the water column and sediment. Thus, the occurrence of diploptene derived from bacterial activity and the carbon isotopic values of diploptene may indicate potential methane seepage during the glacial period in core 06GHSA P6. This implies that a potential dissociation of gas hydrate during glacial periods is observed in the foraminiferal isotopic record and methanotrophic processes in the southern part of Ulleung Basin, East Sea.