Change in Sediment Provenance on the Inner Slope of the Chukchi Rise and Their Paleoenvironmental Implications

Hyo-Jin Koo,Young-Keun Jin,Hyen-Goo Cho

doi:10.3390/app11146491

Hyo-Jin Koo, Young-Keun Jin + Show 1 more

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https://doi.org/10.3390/app11146491

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Abstract

The Arctic Ocean is one of the world’s most remarkable regions with respect to global climate change. The core ARA09C-St03 was analyzed for mineral composition and Nd isotope to determine the sediment provenance and reconstruct the paleoenvironment in the inner slope of the Chukchi Rise. Core ARA09C-St03 represents overall cycles of brown and gray color with three distinct dark brown layers and two pinkish-white layers and is divided into eight sedimentary units based on the lithological feature. The core has a continuous record of the late marine isotope stage (MIS) 5 to the Holocene and in particular provides a particularly high-resolution record from the Last Glacial Maximum (LGM). Sediment is derived mainly from the adjacent East Siberian Sea and the North American region, and changes in sediment provenance are controlled by climate-dependent particle size. During the glacial/stadial periods, sediments in Units 3, 5, and 8 were supplied by the East Siberian Sea via meltwater-derived suspension. The major ice-rafted debris (IRD) events in Units 2, 4, and 7, characterized by abundant dolomite and K/C ratio, were sourced from North America. The North America-derived materials reflect the initiation and disintegration of the Laurentide Ice Sheet and icebergs transported them across the open Arctic Ocean. The differences in provenance within these periods may be related to the scale of the Laurentide Ice Sheet. Interglacial sediments, including those from Units 1 and 6, are of mixed origin from Eurasia and the Canadian Archipelago and may have been transported by oceanic current and seasonal sea ice. These periods are likely associated with the negative Arctic Oscillation (AO) intensifying the Beaufort Gyre.

Highlights

The Arctic Ocean is the smallest of the world’s oceans, with a surface area of 9.5 ×106 km2 (2.6% of the world’s ocean) [1]; it is one of the most remarkable regions with respect to global climate change
ice-rafted debris (IRD) events may be caused by freely circulating icebergs [8,23], and they have been reported as a feature of the deglacial period in the Chukchi Rise [21]
Our results suggest that the Laurentide Ice Sheet during the marine isotope stage (MIS) 2 period (i.e., Last Glacial Maximum (LGM)) with the lowest sea level probably expanded significantly more than in other stadial periods since the late MIS 5 and thereby supplied sediments primarily from the Beaufort Sea

Summary

Introduction

The Arctic Ocean is the smallest of the world’s oceans, with a surface area of 9.5 ×. 106 km (2.6% of the world’s ocean) [1]; it is one of the most remarkable regions with respect to global climate change. The Arctic Ocean influences the global climate mainly through seasonal or permanent sea ice cover and deep-water formation controlling oceanic thermohaline circulation [2]. The Arctic Ocean is a unique sea with surrounding continental shelves that make up. 52.7% of the Arctic Ocean’s surface area [4]. It is surrounded by the continents of Eurasia and North America and is divided into the western and eastern Arctic by the Lomonosov. The western Arctic Ocean includes several seas

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