Particulate Organic Carbon Cycling on the Amundsen Shelf, Antarctic : Insights from Radiocarbon Analysis

• Main Author: 김민경
• Other Authors: 일반대학원 해양학과
• Format: Thesis
• Language: English
• Published: 포항공과대학교 2014
• Subjects: Amundsen Sea; Antarc*; Antarctic; Antarctica; Ice Shelf; Sea ice
• Online Access: http://postech.dcollection.net/jsp/common/DcLoOrgPer.jsp?sItemId=000001675583; https://oasis.postech.ac.kr/handle/2014.oak/2157

Master Various particulate organic carbon (POC) samples were collected including sinking POC, suspended POC in surface water, and sediment on the Amundsen shelf, Antarctica, during the 2012 cruise on the IBRV Araon, and by an instrument mooring.Sinking particles were intercepted at 425m depth by a sediment trap from January 2011 for a year, near the periphery of the Amundsen Sea polynya. Based on the radiocarbon values (as in 14C) and organic carbon contents, sinking POC in the Amundsen sea ice zone were divided into three different patterns. The 14C values were close to the values obtained for suspended POC at the surface during the cruise in summer and remained so for a few months after sea ice was recovered indicating the continued supply of fresh POC. In October, November, and December the 14C values decreased, in close association with increasing content of non-biogenic component in the sinking particles.POC accumulation rate in the sediment was estimated from the 14C values of sediment layers at 4 locations (near the shelf break, polynya near the boundary with the sea ice zone, inside the polynya, near the ice shelf) on the Amundsen Shelf. POC accumulation rate in the polynya was about 20 times higher than near the shelf break. Compared to consistent with the highest primary production in surface water, inside the polynya showed the highest POC accumulation rate in sediment. The age of the source POC supplied to the sediment was close to modern near the shelf break while that to the sediment inside the polynya was old.Sinking POC flux and accumulation in the sediments appear to show spatial variability. The cause of this spatial variability in association with the biological production and physical conditions at surface need further investigation 서남극 아문젠 해는 빙상과 빙붕의 급격한 감소를 보이며 지구 온난화의 영향을 크게 받고 있는 해역 중 한 곳이다. 기후 변화로 인한 해빙의 감퇴는 해양 일차생산자인 식물 플랑크톤에 의한 일차생산을 비롯한 탄소순환 양상에 영향을 미칠 것으로 예상된다. 본 연구에서는 나이와 기원에 대한 정보를 제공할 수 있는 방사성탄소동위원소를 이용하여 아문젠해 유기탄소 순환을 이해하려 하였다.아문젠 해빙역에 퇴적물 트랩을 계류하여 연간 시계열 침강입자 시료를 획득하였으며, ...