Late Pleistocene stratigraphy and palaeoceanographic implications in northern Bering Sea slope sediments: evidence from the radiolarian species Cycladophora davisiana

Abstract

A high-resolution abundance curve of the radiolarian species, Cycladophora davisiana, was obtained from a Late Pleistocene sediment core, PC-23A, which was obtained from the northern slope of the Bering Sea. The abundance pattern of this species was high during the glacial period and low during the Holocene. This general stratigraphic pattern was correlated with a previously reported pattern for the subarctic Pacific Ocean. However, planktonic foraminifera-based accelerator mass spectrometry 14 C dating revealed that a significant peak in the C. davisiana curve during the glacial period correlates to 15.5 ka, which is younger than that previously estimated as being the Last Glacial Maximum. The higher abundance of this species implies that there was well-ventilated water with a large amount of organic matter in the intermediate-water layer. An unusually high propagation of C. davisiana during the earliest Holocene period, Bølling-Allerød (B-A) and Dansgaad-Oescheger interstadial event # 12, was most likely related to a significant increase in the amount of organic matter released into the intermediate-water depths by a brine pump system via ventilation. In addition, centennial-scale variations in the abundance of C. davisiana during the B-A period suggest that the intermediate-water ventilation was sensitively affected by brine rejection during sea ice formation as well as large-scale atmospheric circulations such as the Arctic Oscillation.

Millennial-scale variability of marine productivity and terrigenous matter supply in the western Bering Sea over the past 180 kyr

“…In contrast to TOC and CaCO 3 , we observed only minor increases in opal during the B/A, but a subsequent gradual increase into the Holocene. These results from the western Bering Sea are comparable to opal records from the northern slope (Itaki et al, 2009;Khim et al, 2010;Kim et al, 2011). Despite showing a similar temporal evolution, opal records from Bowers Ridge (Okada et al, 2005;Okazaki et al, 2005;Brunelle et al, 2007Brunelle et al, , 2010, Umnak Plateau (Okada et al, 2005;Okazaki et al, 2005), and the southern Okhotsk Sea (Gorbarenko, 1996;Gorbarenko et al, 2002a, b;Brunelle et al, 2010) have 1.5 to 3-times higher values.…”

“…Umnak Plateau: KH99-3-UMK-3A (Okada et al, 2005;Okazaki et al, 2005;Tanaka and Takahashi, 2005), RC14-121 (Cook et al, 2005). Northern slope: MR06-04-PC23A and -PC24A (Itaki et al, 2009;Khim et al, 2010;Kim et al, 2011;Rella et al, 2012). Dashed black line indicates average maximum sea-ice extent (after Niebauer et al, 1999;Zhang et al, 2010).…”

“…(3) After Eppley and Peterson (1979). Okazaki et al, 2005;Brunelle et al, 2007Brunelle et al, , 2010Itaki et al, 2009;Khim et al, 2010;Kim et al, 2011). At ODP Site 882 in the N Pacific interglacial maxima in CaCO 3 are accompanied by maxima in Ba bio .…”

“…Springer et al, 1996;Niebauer et al, 1999), it might have had a different influence on past oceanatmosphere CO 2 exchange. Paleoceanographic reconstructions in the Bering Sea also revealed reduced export production during the last glacial period, which increased during Termination I and remained high in the Holocene (Gorbarenko, 1996;Cook et al, 2005;Gorbarenko et al, 2005;Okada et al, 2005;Okazaki et al, 2005;Brunelle et al, 2007Brunelle et al, , 2010Itaki et al, 2009;Khim et al, 2010;Kim et al, 2011). This variability was explained by a complex interplay of changes in sea surface temperatures (SST), sea-ice coverage, inflow of Pacific surface waters, and upper-ocean stratification (e.g.…”

Late Quaternary Distribution of RadiolarianCycladophora davisianaas Indication of Possible Ventilation of Intermediate Water in the Subarctic Pacific during the Last Glacial

“…РЕЗУЛЬТАТЫ И ОБСУЖДЕНИЕ В современных осадках Северной Пацифики C. davisiana высокие концентрации >10-20% от общего числа экземпляров в комплексах радио лярий образует в Охотском море, в то время как в открытой субарктической Пацифике и Беринго вом море содержание вида редко превышает 5% [9,30,35]. Также есть сведения о высоком содер жании C. davisiana в поверхностном слое Япон ского моря: >20% в северо западном районе [8] и до 19% в северном районе [23].…”