동해 퇴적물에서 유기화합물( diploptene)의 출현: 메탄방출의 함의

Abstract

Two piston cores (06GHSA P1 and 06GHSA P6) from the Ulleung Baisn of the East Sea were examined to detect the presence of organic compounds (diploptene), and their carbon isotopic variations were also investigated to evaluate their sources. Analytical results from the core records showed that organic compounds (diploptene) occurred in two core have an high fluctuation throughout the core. Especially, in 06GHSA P6 core diplpotene concentration increase during the last glacial maximum (LGM). Analytical values ranges from 632.1 ng/g to 1.7 ng/g (ave. 87 ng/g) in core 06GHSA P6, and from 42.2 ng/g to 1.4 ng/g in core 06GHSA P1 (ave. 20.1 ng/g) in diploptene concentration, repectively. Carbon isotope value of organic compounds (diploptene) range from -56.33 to -60.23 permil suggesting that these diploptene in part is derived from methanotrophic bacteria which decomposed methane in water column and sediment. Therefore, the occurrence of organic compounds (diploptene) derived from bacterial activity, carbon isotopic values of diploptene may indicate the potential methane seeping during glacial period in core 06GHSA P6. This may imply that potential dissociation of gas hydrate during glacial periods may relate with paleoceanographic environmental changes.