• 제목/요약/키워드: 네오디뮴 동위원소

검색결과 3건 처리시간 0.02초

과거 해수 순환을 지시하는 해수기원 네오디뮴 동위원소 비 기록 (Authigenic Neodymium Isotope Record of Past Ocean Circulation)

  • 허영숙;장광철
    • 암석학회지
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    • 제23권3호
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    • pp.249-259
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    • 2014
  • 해수의 순환이 지구표면의 열 분배 및 궤도함수주기와 천년주기의 기후변화와 밀접한 관계가 있음이 알려지면서 과거 해수의 흐름을 지시할 수 있는 지시자의 개발이 관심을 끌고 있다. 이 논평에서는 해수 자생성 네오디뮴 동위원소 비를 해수순환의 지시자로 활용하는 원리와 분석방법 그리고 두 가지 적용사례를 소개한다. 먼저 지난 빙하기-간빙기와 아빙기-아간빙기에 걸쳐 북대서양심층수 세기의 변화를 명확히 볼 수 있는 예를 소개한다. 다음으로는 북극해에서 담수의 유입과 해수순환을 재구성한 예를 보인다.

퇴적물의 네오디뮴 동위원소 비를 활용한 북극 고환경 복원 (Application of Sedimentary Neodymium Isotopes to the Reconstruction of the Arctic Paleoceanography)

  • 장광철;남승일
    • Ocean and Polar Research
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    • 제45권2호
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    • pp.89-102
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    • 2023
  • Climate and environmental changes in the Arctic Ocean due to global warming have been linked to extreme climate change in mid-latitude regions, including the Korean Peninsula, requiring a better understanding of the Arctic climate system based on the paleo-analog. This review introduces three paleoenvironmental research cases using neodymium isotopes (143Nd/144Nd, εNd) measured on two different fractions of marine sediments: silicate-bound 'detrital' and Fe-Mn oxide-dominated 'authigenic' fractions. In the first case, detrital εNd in core HH17-1085-GC on the continental shelf off northern Svalbard was used for tracing changes in sediment provenance and associated glacier behavior over the last 16.3 ka. The second case showed the potential use of authigenic εNd as a quasi-conservative water mass tracer. Three prominent εNd peaks and troughs observed in core PS72/410-1 from the Mendeleev Ridge in the western Arctic Ocean over the past 76 ka suggested episodic meltwater discharge events during 51~46, 39~35 and 21~13 ka BP. The last case proposed the use of the difference between authigenic and detrital εNd as a proxy for reconstructing glacier fluctuation. The idea is based on the assumption that enhanced glacial erosion during glacier advances can supply sufficient freshly-exposed rock substrate for incongruent weathering, potentially leading to greater isotopic decoupling between bedrock and dissolved weathering products as recorded in detrital and authigenic εNd, respectively. Thus, it would be worthwhile to take advantage of sedimentary εNd to improve our understanding of past environmental changes in polar regions.