Late Quaternary paleoceanographic changes in the southwestern Okhotsk Sea: Evidence from geochemical, radiolarian, and diatom records

“…This event has been recognised widely in the North Pacific and its marginal seas (e.g. Kruglikova, 1974;Morley et al, 1982Morley and Robinson, 1986;Morley and Nigrini, 1995;Matul et al, 2002;Okazaki et al, 2005b;Tanaka and Takahashi, 2005;Itaki et al, 2007). found that this event occurred at 3.16 m at ODP site 883 in the northwestern Pacific.…”

Section: Age Modelmentioning

confidence: 99%

“…Although Matul et al (2002) proposed this event to be 28 ka in the central Okhotsk Sea, that age may have been younger than the actual age due to a bioturbation effect in the slow sedimentation core LV28-42-4. Indeed, Okazaki et al (2005b) showed this event to be 47-48 ka in the high sedimentation core MD01-2412 from the southwestern Okhotsk Sea.…”

Section: Age Modelmentioning

confidence: 99%

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

Itaki

Uchida

Kim

et al. 2009

J Quaternary Science

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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.

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“…In addition to their relationship to biological productivity (Ishikawa and Furuya, 2004;Allen JT et al, 2005), diatom assemblages also reflect the physical conditions of the water masses in which they dwell Crosta et al, 2005;Onodera et al, 2005;Romero et al, 2005). For example, diatom assemblages have been used to reconstruct past sea surface temperatures, salinities, sea ice extension, surface circulation and coastal environment changes in the North Pacific (Katsuki et al, 2003;Koizumi et al, 2004Koizumi et al, , 2006Barron et al, 2005;Katsuki and Takahashi, 2005;Khim et al, 2005;Okazaki et al, 2005;Ryu et al, 2005). However, diatom evidence has not yet been used to advance our understanding on palaeoceanographic and palaeoclimatic changes during interglacial-glacial cycles in the ECS.…”

Section: Introductionmentioning

confidence: 99%

The last 100 000 years' palaeoenvironmental changes inferred from the diatom assemblages of core MD012404 from the Okinawa Trough, East China Sea

Chang

Wang

Chen

2009

J Quaternary Science

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The diatom assemblage records preserved in a sedimentary core MD012404 retrieved from the Okinawa Trough in the East China Sea (ECS) imply palaeoenvironmental changes of the last 100 ka. Our statistical analyses of diatom species abundance data indicate that the assemblages dominate open ocean and warm water, coastal water and freshwater masses in the ECS. These proxy species were used to infer the long‐term variation in surface hydrological conditions and palaeoclimate. Cycles of ca. 23 ka observed in the relative abundance of the tychopelagic species Paralia sulcata indicate that the increases in precipitation driven by solar insolation might have controlled the diatom assemblages in the ECS. The diatom records also indicate relatively low abundances of tropical, tychopelagic and freshwater species during millennial‐scale cold events such as the Younger Dryas and Heinrich events, which have been well expressed in the high‐latitude Northern Hemisphere climate. The floral patterns are interpreted as synchronous cooling and more saline sea surface conditions in the ECS caused by the enhanced Asian winter monsoon during the Northern Hemisphere cold events. The higher abundances of tropical species during deglaciation and the Holocene might have been linked to gradual increases in the inflow of the Kuroshio into the Okinawa Trough. The records also suggest a temporary reduction in tropical species from 5 to 3 ka, corresponding to the Pulleniatina Minimum Event during which the warm‐water planktic foraminifer Pulleniatina obliquiloculata was rare. Copyright © 2009 John Wiley & Sons, Ltd.

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Late Quaternary paleoceanographic changes in the southwestern Okhotsk Sea: Evidence from geochemical, radiolarian, and diatom records

Cited by 72 publications

References 51 publications

Millennial-scale variations of sea-ice expansion in the southwestern part of the Okhotsk Sea during the past 120 kyr: Age model and ice-rafted debris in IMAGES Core MD01-2412

Millennial-scale variations of sea-ice expansion in the southwestern part of the Okhotsk Sea during the past 120 kyr: Age model and ice-rafted debris in IMAGES Core MD01-2412

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

The last 100 000 years' palaeoenvironmental changes inferred from the diatom assemblages of core MD012404 from the Okinawa Trough, East China Sea

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