scholarly journals Intermediate- and Deep-Water Oxygenation History in the Subarctic North Pacific During the Last Deglacial Period

2021 ◽  
Vol 9 ◽  
Author(s):  
Ekaterina Ovsepyan ◽  
Elena Ivanova ◽  
Martin Tetard ◽  
Lars Max ◽  
Ralf Tiedemann
Keyword(s):  
Sea Level ◽  
Deep Water ◽  
Bering Sea ◽  
North Pacific ◽  
Intermediate Water ◽  
Western Bering Sea ◽  
Water Oxygen ◽  
Wide Range ◽  
The Bering Sea ◽  
Oxygen Concentrations

Deglacial dissolved oxygen concentrations were semiquantitatively estimated for intermediate and deep waters in the western Bering Sea using the benthic foraminiferal-based transfer function developed by Tetard et al. (2017), Tetard et al. (2021a). Benthic foraminiferal assemblages were analyzed from two sediment cores, SO201-2-85KL (963 m below sea level (mbsl), the intermediate-water core) and SO201-2-77KL (2,163 mbsl, the deep-water core), collected from the Shirshov Ridge in the western Bering Sea. Intermediate waters were characterized by an oxygen content of ∼2.0 ml L−1 or more during the Last Glacial Maximum (LGM)–Heinrich 1 (H1), around 0.15 ml L−1 during the middle Bølling/Allerød (B/A)–Early Holocene (EH), and a slight increase in [O2] (∼0.20 ml L−1) at the beginning of the Younger Dryas (YD) mbsl. Deep-water oxygen concentrations ranged from 0.9 to 2.5 ml L−1 during the LGM–H1, hovered around 0.08 ml L−1 at the onset of B/A, and were within the 0.30–0.85 ml L−1 range from the middle B/A to the first half of YD and the 1.0–1.7 ml L−1 range from the middle to late Holocene. The [O2] variations remind the δ18O NGRIP record thereby providing evidence for a link between the Bering Sea oxygenation at intermediate depths and the deglacial North Atlantic climate. Changes in the deep-water oxygen concentrations mostly resemble the deglacial dynamics of the Southern Ocean upwelling intensity which is supposed to be closely coupled with the Antarctic climate variability. This coherence suggests that deglacial deep-water [O2] variations were primarily controlled by changes in the circulation of southern-sourced waters. Nevertheless, the signal from the south at the deeper site might be amplified by the Northern Hemisphere climate warming via an increase in sea-surface bioproductivity during the B/A and EH. A semi-enclosed position of the Bering Sea and sea-level oscillations might significantly contribute to the magnitude of oxygenation changes in the study area during the last deglaciation. Interregional correlation of different proxy data from a wide range of water depths indicates that deglacial oxygenation changes were more pronounced in the Bering and Okhotsk marginal seas than along the open-ocean continental margin and abyssal settings of the North Pacific.

scholarly journals Benthic foraminifera indicate Glacial North Pacific Intermediate Water and reduced primary productivity over Bowers Ridge, Bering Sea, since the Mid-Brunhes Transition

2019 ◽  
Vol 38 (2) ◽  
pp. 177-187 ◽  
Author(s):  
Sev Kender ◽  
Adeyinka Aturamu ◽  
Jan Zalasiewicz ◽  
Michael A. Kaminski ◽  
Mark Williams
Keyword(s):  
Sea Ice ◽  
High Latitude ◽  
Bering Sea ◽  
North Pacific ◽  
The Arctic ◽  
Intermediate Water ◽  
North Pacific Intermediate Water ◽  
High Productivity ◽  
Very High ◽  
The Bering Sea

Abstract. The Mid-Brunhes Transition (MBT) saw an increase in the amplitude of glacial cycles expressed in ice core and deep ocean records from about 400 ka, but its influence on high-latitude climates is not fully understood. The Arctic Ocean is thought to have warmed and exhibited reduced sea ice, but little is known of sea ice marginal locations such as the Bering Sea. The Bering Sea is the link between the Arctic and Pacific Ocean and is an area of high productivity and CO2 ventilation; it hosts a pronounced oxygen minimum zone (OMZ) and is thought to be the location of Glacial North Pacific Intermediate Water (GNPIW) formation in the Pleistocene. To understand palaeoceanographic change in the region, we analysed benthic foraminiferal faunas from Bowers Ridge (Site U1342, 800 m of water depth) over the past 600 kyr, as they are uniquely well preserved and sensitive to changes in deep and surface ocean conditions. We identified and imaged 71 taxa and provide a full taxonomy. Foraminiferal preservation is markedly higher during glacials, indicating the presence of less corrosive GNPIW. The most abundant species are Bulimina exilis, Takayanagia delicata, Alabaminella weddellensis, Gyroidina sp. 2, Cassidulina laevigata, Islandiella norcrossi, and Uvigerina bifurcata, consistent with broadly high net primary production throughout the last 600 kyr. Correspondence analysis shows that the most significant Assemblage 1 comprises B. exilis, T. delicata, Bolivina spissa, and Brizalina, which occur sporadically within intervals of laminated, biogenic-rich sediment, mostly during glacials and also some deglacials, and are interpreted as indicating very high productivity. Other assemblages contain the phytodetritivore species A. weddellensis, I. norcrossi, and C. laevigata, indicative of seasonal phytoplankton blooms. Before the MBT, more numerous intervals of the very high-productivity Assemblage 1 and A. weddellensis occur, which we suggest reflect a time of more sea-ice-related seasonal stratification and ice edge blooms. Our inference of a decrease in sea ice meltwater stratification influence in the central Bering Sea after the MBT is consistent with records showing that the Arctic and Pacific Ocean warmed during glacials and suggests that high-latitude productivity and sea ice changes were an important feature of this climate event.

Arctic archaeologies: recent work on Beringia

Antiquity ◽  
2015 ◽  
Vol 89 (345) ◽  
pp. 740-742 ◽  
Author(s):  
Herbert Maschner
Keyword(s):  
Bering Sea ◽  
North Pacific ◽  
Yukon Territory ◽  
The Arctic ◽  
Land Bridge ◽  
Far North ◽  
North East ◽  
Bering Land Bridge ◽  
Last Glaciation ◽  
The Bering Sea

This review considers three books on the archaeology of territories situated around the Bering Sea—a region often referred to as Beringia, adopting the term created for the Late Pleistocene landscape that extended from north-east Asia, across the Bering Land Bridge, to approximately the Yukon Territory of Canada. This region is critical to the archaeology of the Arctic for two fundamental reasons. First, it is the gateway to the Americas, and was certainly the route by which the territory was colonised at the end of the last glaciation. Second, it is the place where the entire Aleut-Eskimo (Unangan, Yupik, Alutiiq, Inupiat and Inuit) phenomenon began, and every coastal culture from the far north Pacific, to Chukotka, to north Alaska, and to arctic Canada and Greenland, has its foundation in the cultural developments that occurred around the Bering Sea.

scholarly journals A 36 kyr geochemical record from the Sea of Japan of organic matter flux variations and changes in intermediate water oxygen concentrations

1999 ◽  
Vol 14 (2) ◽  
pp. 248-259 ◽  
Author(s):  
John Crusius ◽  
Thomas F. Pedersen ◽  
Stephen E. Calvert ◽  
Gregory L. Cowie ◽  
Tadamichi Oba
Keyword(s):  
Organic Matter ◽  
Sea Of Japan ◽  
The Sea Of Japan ◽  
Intermediate Water ◽  
Water Oxygen ◽  
Matter Flux ◽  
Oxygen Concentrations

scholarly journals Millennial-scale climate change and intermediate water circulation in the Bering Sea from 90 ka: A high-resolution record from IODP Site U1340

2013 ◽  
Vol 28 (1) ◽  
pp. 54-67 ◽  
Author(s):  
Shiloh A. Schlung ◽  
A. Christina Ravelo ◽  
Ivano W. Aiello ◽  
Dyke H. Andreasen ◽  
Mea S. Cook ◽  
...  
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Bering Sea ◽  
Water Circulation ◽  
Intermediate Water ◽  
The Bering Sea ◽  
Site U1340 ◽  
Millennial Scale

Stable Isotope and Lithologic Evidence of Late-Glacial and Holocene Oceanography of the Northwestern Pacific and Its Marginal Seas

1996 ◽  
Vol 46 (3) ◽  
pp. 230-250 ◽  
Author(s):  
Sergei A. Gorbarenko
Keyword(s):  
Bering Sea ◽  
Planktonic Foraminifera ◽  
Late Glacial ◽  
Northwestern Pacific ◽  
Intermediate Water ◽  
Regional Environment ◽  
The Holocene ◽  
Marginal Seas ◽  
The North ◽  
The Bering Sea

Stable isotopes, geochemical, lithological, and micropaleontological results from cores from the far northwest (FNW) Pacific and the Okhotsk and Bering seas are used to reconstruct the regional environment for the last glaciation, the deglacial transition, and the Holocene. δ18O records of planktonic foraminifera of the region show two “light” shifts during deglacial time, provoked by the freshening of the surface water and climate warming. These north Pacific terminal events (T1ANP and T1BNP) with ages of 12,500 and 9300 yr B.P., respectively, occur almost simultaneously with two episodes of accelerated glacier melting around the North Atlantic. Along with the isotopic shifts, the CaCO3 content in regional sediments increased abruptly (1A and 1B carbonate peaks), probably due to changes of productivity and pore water chemistry of surface sediments. Organic matter and opal concentration increased during the transition (between T1ANP and T1BNP events) in the sediments of the FNW Pacific and the southern part of the Bering Sea and opal content increased in the Holocene in the Bering and Okhotsk Seas. δ13C records of cores from the Okhotsk and Bering seas and the FNW Pacific do not contradict the hypothesis of increased intermediate water formation in the region during glaciation. During deglaciation, accumulation of the coarse terrigenous component decreased in sediments of the Bering Sea and the FNW Pacific before the T1ANP event, probably as a result of rising sea level and opening of the Bering Strait.

Nonrandom distribution of chum salmon stocks in the Bering Sea and the North Pacific Ocean estimated using mitochondrial DNA microarray

2009 ◽  
Vol 75 (2) ◽  
pp. 359-367 ◽  
Author(s):  
Shogo Moriya ◽  
Shunpei Sato ◽  
Moongeun Yoon ◽  
Tomonori Azumaya ◽  
Shigehiko Urawa ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Dna Microarray ◽  
Bering Sea ◽  
North Pacific ◽  
Chum Salmon ◽  
North Pacific Ocean ◽  
The North ◽  
Nonrandom Distribution ◽  
The North Pacific ◽  
The Bering Sea

Single-nucleotide polymorphisms reveal distribution and migration of Chinook salmon (Oncorhynchus tshawytscha) in the Bering Sea and North Pacific Ocean

2013 ◽  
Vol 70 (1) ◽  
pp. 128-141 ◽  
Author(s):  
Wesley A. Larson ◽  
Fred M. Utter ◽  
Katherine W. Myers ◽  
William D. Templin ◽  
James E. Seeb ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Chinook Salmon ◽  
Bering Sea ◽  
North Pacific ◽  
Oncorhynchus Tshawytscha ◽  
North Pacific Ocean ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
And Migration ◽  
The Bering Sea

We genotyped Chinook salmon (Oncorhynchus tshawytscha) from the Bering Sea and North Pacific Ocean for 43 single-nucleotide polymorphisms (SNPs) to investigate seasonal distribution and migration patterns. We analyzed 3563 immature fish from 22 spatiotemporal strata; composition analyses were performed using genotype data from spawning stocks spanning the species range. Substantial variation in stock composition existed among spatial and seasonal strata. We inferred patterns of seasonal migration based upon these data along with data from previous tag, scale, and parasite studies. We found that stocks from western Alaska and Yukon River overwinter on the Alaska continental shelf then travel to the middle and western Bering Sea during spring–fall. Stocks from California to Southeast Alaska were distributed in Gulf of Alaska year-round, with a substantial portion of this group migrating northward to the eastern Bering Sea during spring–fall. Proportions of Russian stocks increase when moving east to west in both the Bering Sea and North Pacific Ocean. These data can be used to better understand the impacts of fisheries and climate change on this valuable resource.

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