Surface sediment diatom distribution and Holocene paleotemperature variations in the Greenland, Iceland and Norwegian Sea

Karpuz, Nalân; Schrader, Hans

doi:10.1029/pa005i004p00557

Cited by 220 publications

(184 citation statements)

References 35 publications

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“…Supported by a strong atmospheric warming, the improved sea surface conditions persisted until about 6000 cal yr BP. Similar ages for the Holocene optimal conditions (9000-5000 14 C years BP) were recorded from the Nordic Seas by Koç Schrader (1990), Koç Karpuz and and Koç et al (1993).…”

Section: Comparison and Discussionsupporting

confidence: 54%

“…In modern assemblages around Iceland, it is mainly found in the surface sediments south and west of Iceland, where the warm Irminger Current has a strong impact today ( Jiang et al, 2001). The presence of the Irminger Current is also indicated by Thalassionema nitzschioides and Paralia sulcata, which constitute the main species of the Norwegian-Atlantic Current assemblage in the Greenland-Iceland-Norwegian seas (Koç Karpuz and Schrader, 1990). Both species are associated with the Atlantic waters flowing into the Skagerrak-Kattegat in the eastern North Atlantic ( Jiang, 1996).…”

Section: Diatomsmentioning

confidence: 99%

“…The ages of the tephra markers (Vedde and Saksunarvatn) are shown with stippled lines. A strong influence of the Irminger Current on the North Icelandic shelf is indicated by Thalassiosira oestrupii, which is the main diatom species of the Atlantic assemblage in the modern warm North Atlantic water mass with salinities higher than 35.3 and sea surface temperatures above 3°C (Koç Karpuz and Schrader, 1990). In modern assemblages around Iceland, it is mainly found in the surface sediments south and west of Iceland, where the warm Irminger Current has a strong impact today ( Jiang et al, 2001).…”

Section: Diatomsmentioning

confidence: 99%

“…It is also associated with the West Greenland Current ( De Séve, 1999), and it is very common in the North Atlantic, extending to the northern Arctic ( Hustedt, 1930-1960and Hendey, 1964. It is the main component of the Arctic-Norwegian waters mixing assemblage, which coincides with areas of mixture between the Arctic and the Atlantic waters ( Koç Karpuz and Schrader, 1990). …”

Section: Diatomsmentioning

confidence: 99%

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Environmental changes off North Iceland during the deglaciation and the Holocene: foraminifera, diatoms and stable isotopes

Knudsen

Jiang

Jansen

et al. 2004

Marine Micropaleontology

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A combined study of foraminifera, diatoms and stable isotopes in marine sediments off North Iceland records major changes in sea surface conditions since about 15800 cal years (yr) BP. Results are presented from two gravity cores obtained at about 400 m water depth from two separate sedimentary basins on each side of the submarine Kolbeinsey Ridge. The chronology of the sedimentary record is based partly on AMS 14 C dates, partly on the Vedde and the Saksunarvatn tephra markers, as well as the historical Hekla AD 1104 tephra. During the regional deglaciation, the planktonic foraminiferal assemblages are characterised by consistently high percentages of sinistrally coiled Neogloboquadrina pachyderma. However, major environmental variability is reflected by changes in stable isotope values and diatom assemblages. Low 18 O values indicate a strong freshwater peak as well as possible brine formation by sea-ice freezing during a pre-Bølling interval (Greenland Stadial 2), corresponding to the Heinrich 1 event. The foraminifera suggest a strong concurrent influence of relatively warm and saline Atlantic water, and both the foraminifera and the diatoms suggest mixing of cold and warm water masses. Similar but weaker environmental signals are observed during the Younger Dryas (Greenland Stadial 1) around the level of the Vedde Ash. Each freshwater peak is succeeded by an interval of severe cooling both at the beginning of the Bølling-Allerød Interstadial Complex (Greenland Interstadial 1) and during the Preboreal, presumably associated with the onset of intense deep water formatiom in the Nordic Seas. The Holocene thermal optimum, between 10200 and about 7000 cal years (yr) BP, is interrupted by a marked cooling of the surface waters around 8200 cal yr BP. This cold event is clearly expressed by a pronounced increase in the percentages of sinistrally coiled N. pachyderma, corresponding to a temperature decrease of about 3°C. A general cooling in the area is indicated after 7000-6000 cal yr BP, both by the diatom data and by the planktonic foraminiferal data. After a severe cooling around 6000 cal yr BP, the planktonic foraminiferal assemblages suggest a warmer interval between 5500 and 4500 cal yr BP. Minor temperature fluctuations are reflected both in the foraminiferal and in the diatom data in the upper part of the record, but the time resolution of the present data is not high enough to pick up details in environmental changes through the late Holocene.

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Section: Comparison and Discussionsupporting

confidence: 54%

Section: Diatomsmentioning

confidence: 99%

Section: Diatomsmentioning

confidence: 99%

Section: Diatomsmentioning

confidence: 99%

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Environmental changes off North Iceland during the deglaciation and the Holocene: foraminifera, diatoms and stable isotopes

Knudsen

Jiang

Jansen

et al. 2004

Marine Micropaleontology

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“…The hydrographical setting ( Fig. 2a-c) with cold, low-salinity arctic water masses in the west and warm, high salinity Atlantic water masses in the east, changed through the latest glacial-interglacial cycle (Koç-Karpuz and Schrader, 1990;Koç et al, 1993Koç et al, , 1996. The various modern water masses can be recognized not only by their hydrographical parameters, but also by their micro-, zoo-, and phytoplankton assemblages.…”

Section: Introductionmentioning

confidence: 99%

Radiolarian faunal provinces in surface sediments of the Greenland, Iceland and Norwegian (GIN) Seas

Bjørklund¹,

Cortese²,

Swanberg³

et al. 1998

Marine Micropaleontology

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The overall abundance and species composition of the polycystine and phaeodarian radiolaria have been determined in 63 surface sediment samples from the GIN Seas. These results are compared to chemical and physical properties of the overlying water masses. There are three abundance maxima in the distribution of radiolarian skeletal debris preserved in these surface sediments, centered on the Iceland Plateau, southern Norwegian Basin and northern Norwegian Basin. The most commonly encountered species were: (a) Spumellarida -Actinomma boreale, A. leptoderma, Larcospira minor, and Phorticium clevei, (b) Nassellarida -Amphimelissa setosa, Artobotrys boreale, Lithomelissa setosa, Lithocampe platycephala, Pseudodictyophimus gracilipes, Cycladophora davisiana, and Lithomitra lineata. Based on factor analysis of the core-top assemblages, the radiolarian species were grouped into three associations: Factor 1 -a polar-and arctic water association dominated by Amphimelissa setosa (varimax factor score 5.269), high factor component values are found in the Iceland Plateau area and in a wedge just north of the Iceland-Faeroe Ridge; Factor 2 -an Atlantic water association dominated by Pseudodictyophimus gracilipes (3.247), Lithomelissa setosa (2.731), and Actinomma boreale (1.851), high factor component values are found in the eastern part of the Norwegian Sea, particularly in the area under the influence of the Norwegian Current; and Factor 3 -an Atlantic and arctic water mixed association dominated by Lithocampe platycephala (3.251), Lithomelissa setosa ( 2.176), Actinomma leptoderma (1.994) and Artobotrys boreale (1.504), high factor component values are found immediately to the east of the Iceland Plateau in correspondence to the deepest part of the Norwegian Basin. The correlation coefficients obtained between seasonal sea surface temperature and Factors 1 .R 2 D 0:835/, and 2 .R 2 D 0:891/ show a good fit, whilst for Factor 3 there was a less marked .R 2 D 0:497/, but still significant at the 5% confidence level, correlation for fifth-degree polynomial regression functions. The factors correlated better with the summer than the winter sea surface temperatures. However, at 20, 50, 100 and 200 m depth, the correlation became increasingly better, particularly so for the winter situation. The highest species richness for polycystine radiolarians (>28 species) was found in the warm Atlantic domain, the lowest (<24 species) was found in the colder arctic and polar domains, whilst an area approximating the position of the Arctic front had between 24 and 28 species. © 1998 Elsevier Science B.V. All rights reserved.Keywords: radiolaria; Recent; Norwegian Sea; Iceland Sea; paleotemperature; factor analysis Ł Corresponding author. Tel.: C47 2285-1669; E-mail: kjell.bjorklund@toyen.uio.no 0377-8398/98/$19.00 c 1998 Elsevier Science B.V. All rights reserved. PII: S 0 3 7 7 -8 3 9 8 ( 9 8 ) 0 0 0 1 3 -9 106 K.R. Bjørklund et al. / Marine Micropaleontology 35 (1998)

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An event stratigraphy for the Last Termination in the North Atlantic region based on the Greenland ice-core record: a proposal by the INTIMATE group

et al. 1998

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It is suggested that the GRIP Greenland ice‐core should constitute the stratotype for the Last Termination. Based on the oxygen isotope signal in that core, a new event stratigraphy spanning the time interval from ca. 22.0 to 11.5 k GRIP yr BP (ca. 19.0–10.0 k 14C yr BP) is proposed for the North Atlantic region. This covers the period from the Last Glacial Maximum, through Termination 1 of the deep‐ocean record, to the Pleistocene–Holocene boundary, and encompasses the Last Glacial Late‐glacial of the traditional northwest European stratigraphy. The isotopic record for this period is divided into two stadial episodes, Greenland Stadials 1 (GS‐1) and 2 (GS‐2), and two interstadial events, Greenland Interstadials 1 (GI‐1) and2 (GI‐2). In addition, GI‐1 and GS‐2 are further subdivided into shorter episodes. The event stratigraphy is equally applicable to ice‐core, marine and terrestrial records and is considered to be a more appropriate classificatory scheme than the terrestrially based radiocarbon‐dated chronostratigraphy that has been used hitherto. © 1998 John Wiley & Sons, Ltd.

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Surface sediment diatom distribution and Holocene paleotemperature variations in the Greenland, Iceland and Norwegian Sea

Cited by 220 publications

References 35 publications

Environmental changes off North Iceland during the deglaciation and the Holocene: foraminifera, diatoms and stable isotopes

Environmental changes off North Iceland during the deglaciation and the Holocene: foraminifera, diatoms and stable isotopes

Radiolarian faunal provinces in surface sediments of the Greenland, Iceland and Norwegian (GIN) Seas

An event stratigraphy for the Last Termination in the North Atlantic region based on the Greenland ice-core record: a proposal by the INTIMATE group

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