• Title/Summary/Keyword: 네오디뮴 동위원소

Search Result 3, Processing Time 0.017 seconds

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

  • Huh, Youngsook;Jang, Kwangchul
    • The Journal of the Petrological Society of Korea
    • /
    • v.23 no.3
    • /
    • pp.249-259
    • /
    • 2014
  • Proxies for paleo-circulation are drawing much interest with the recognition that ocean circulation plays an important part in the redistribution of heat and climate change on orbital and millennial timescales. In this review, we will introduce how neodymium isotope ratios of the authigenic fraction of marine sediments can be used as a proxy for ocean circulation along with analytical methods and two case studies. The first case study shows how the North Atlantic Deep Water (NADW) has varied over the glacial-interglacial and stadial-interstadial periods. The second case study shows how the freshwater budget and water circulation within the Arctic Ocean can be reconstructed for the last glacial period.

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

  • Kwangchul Jang;Seung-Il Nam
    • Ocean and Polar Research
    • /
    • v.45 no.2
    • /
    • pp.89-102
    • /
    • 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.