Glacial and environmental changes in northern Svalbard over the last 16.3 ka inferred from neodymium isotopes

Type Article
Date 2021-06
Language English
Author(s) Jang Kwangchul1, Ahn Youngkyu1, Joe Young Jin1, Braun Carmen A.2, Joo Young Ji1, Kim Jung-Hyun1, Bayon Germain3, Forwick Matthias2, Vogt Christoph4, Nam Seung-Il1
Affiliation(s) 1 : Korea Polar Research Institute, Incheon 21990, Republic of Korea
2 : UiT The Arctic University of Norway, Department of Geosciences, NO-9037 Tromsø, Norway
3 : IFREMER, Marine Geosciences Unit, F-29280 Plouzané, France
4 : Crystallography, FB05 Geosciences & MARUM, University of Bremen, Klagenfurter Strasse 2-4, 28359 Bremen, Germany
Source Global And Planetary Change (0921-8181) (Elsevier BV), 2021-06 , Vol. 201 , P. 103483 (15p.)
DOI 10.1016/j.gloplacha.2021.103483
Keyword(s) Neodymium isotopes, Svalbard-Barents Sea Ice Sheet, Hinlopen strait, Svalbard, Glacial activity
Abstract

The reconstruction of past ice sheet extents and dynamics in polar regions is essential for understanding the global climate system and obtaining more reliable predictions of future climate change. Here, we present a multi-proxy dataset integrating the Nd isotopic compositions (εNd) of paired detrital and authigenic iron oxide fractions, grain size distributions, organic geochemistry, and mineral assemblages in a glacimarine sediment core (core HH17–1085-GC) retrieved from the continental shelf off northern Svalbard. Our results indicate variability in sediment provenance and chemical weathering patterns since the last deglaciation, allowing us to distinguish a succession of distinct paleoclimate events: 1) a general retreat of the Svalbard-Barents Sea Ice Sheet (SBIS) from the continental shelf before ca. 16.3 ka BP; 2) an intense episode of meltwater discharge related to massive glacier loss between ca. 12.1–9.9 ka BP; and 3) a period of reduced meltwater input between ca. 9.9 and ca. 2.7 ka BP followed by 4) a phase of glacier re-advance over the last two millennia. Evidence for the prolonged supply of radiogenic detrital εNd and dolomite at the site of core HH17–1085-GC indicates that the onset of deglaciation offshore northeastern Svalbard may have occurred at least 1 ka later than that at the northwestern shelf, which can be further evaluated by obtaining a more precise end-member determination for the northeastern source with a quantitative εNd dataset from Nordaustrandet. In the context where both polar sea-ice and oceanic circulation are expected to have played minor roles in determining the εNd composition of sedimentary Fe oxyhydroxide phases, the evidence for pronounced Nd isotopic decoupling between paired authigenic and detrital signatures (ΔεNd) at ca. 15.2 and 14.1 ka BP is interpreted as reflecting chemical weathering changes following the retreat of the SBIS on northern Svalbard, probably corresponding to punctual episodes of glacial re-advances. Our findings provide a better understanding of the deglacial history of northern Svalbard during and after the last deglaciation and highlight the utility of Nd isotopes as a proxy for reconstructing paleo-cryosphere changes.

Full Text
File Pages Size Access
Author's final draft 45 2 MB Open access
31 KB Access on demand
15 9 MB Access on demand
Top of the page

How to cite 

Jang Kwangchul, Ahn Youngkyu, Joe Young Jin, Braun Carmen A., Joo Young Ji, Kim Jung-Hyun, Bayon Germain, Forwick Matthias, Vogt Christoph, Nam Seung-Il (2021). Glacial and environmental changes in northern Svalbard over the last 16.3 ka inferred from neodymium isotopes. Global And Planetary Change, 201, 103483 (15p.). Publisher's official version : https://doi.org/10.1016/j.gloplacha.2021.103483 , Open Access version : https://archimer.ifremer.fr/doc/00688/80049/