scholarly journals The Eemian interglacial in the North European plain and adjacent areas

2000 ◽  
Vol 79 (2-3) ◽  
pp. 217-231 ◽  
Author(s):  
Charles Turner
Keyword(s):  
Deep Sea ◽  
North Atlantic Ocean ◽  
Rapid Development ◽  
Ice Core ◽  
Late Glacial ◽  
Glacial Refugia ◽  
The Arctic ◽  
Massif Central ◽  
The Balkans ◽  
The North

AbstractMany small deposits of Eemian age, including the stratotype, are found right across the North European plain. In adjacent areas, this interglacial is known by local names such as Ipswichian (Britain), Luhe or Ribains (France), Riss-Würm interglacial (Alps) and Mikulinian (Poland and Russia). It correlates primarily with MIS 5e of the deep-sea stratigraphy, though boundaries may not be exactly the same. Basins containing Eemian sediments rest directly on morainic deposits of all three Saalian ice advances, which must all, therefore, fall within MIS 6.Indicator species of both plants and animals suggest that mean July temperatures in the early-temperate part of the interglacial were warmer than during the Holocene. For many years, palynologists have recognised a very uniform succession of temperate tree acme pollen zones and a substantial late-temperate expansion of Carpinus as hallmarks of this interglacial across much of northern Europe. In southern England, however, deposits with a similar pollen signature are being recognised on stratigraphie and palaeontological grounds as characterising not only the Ipswichian but also the previously poorly-defined interglacial stage correlating with MIS 7. High Carpinus values are known from these latter sites and from the Le Bouchet inter-glacial of the French Massif Central, also clearly correlated with MIS 7. Thus stratigraphie confusion and misinterpretations may have occurred at supposedly Eemian/Ipswichian sites unrelated to the glacial stratigraphy or to deep continuous records.The uniformity and rapid development of Eemian vegetational successions may be ascribed to (1) rapid warming and the lack of any late-glacial climatic oscillation on the scale of the Younger Dryas, (2) the development of an open marine connection in the first half of the interglacial from the English Channel across the North and Baltic Seas to the White Sea and the Arctic Ocean, and (3) the occurrence of Saalian per-glacial refugia for Carpinus, not only in the Balkans but also on the Iberian peninsula, permitting much more rapid northward colonisation of Europe during this interglacial.The question of climatic events within the Eemian is far from settled. Not only is the ice-core evidence ambiguous and awaiting further clarification, but the scale and synchroneity of proposed events at different continental sites in both northern and southern Europe show no clear pattern at present; clearly there is a need for more detailed investigation and interpretation. Likewise there is ongoing debate about the duration of this interglacial and its detailed correlation with the deep-sea core record and events within the North Atlantic Ocean.

scholarly journals XXVI. On the Rhizopodal Fauna of the Deep Sea

1870 ◽  
Vol 18 (114-122) ◽  
pp. 59-62 ◽  
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
North Atlantic Ocean ◽  
General Rule ◽  
Equatorial Region ◽  
The Arctic ◽  
Shallow Waters ◽  
Arctic Seas ◽  
The North ◽  
And Diffusion

The Author commences by referring to the knowledge of the Rhizopodal Fauna of the Deep Sea which has been gradually acquired by the examination of specimens of the bottom brought up by the Sounding-apparatus; and states that whilst this method of investigation has made known the vast extent and diffusion of Foramimferal life at great depths,-especially in the case of Globigerina-mud , which has been proved to cover a large part of the bottom of the North Atlantic Ocean,—it has not added any new Generic types to those discoverable in comparatively shallow waters. With the exception of a few forms, which, like find their most congenial home, and attain their greatest development, at great depths, the general rule has seemed to be that Foramimfera are progressively dwarfed in proportion to increase of depth, as they are y a change from a warmer to a colder climate; those which are brought up from great depths in the Equatorial region bearing a much stronger resemblance to those of the colder-temperate, or even of the Arctic seas, than to the littoral forms of their own region.

scholarly journals Geochronological reconsideration of the eastern European key loess section at Stayky in Ukraine

2014 ◽  
Vol 10 (2) ◽  
pp. 783-796 ◽  
Author(s):  
A. Kadereit ◽  
G. A. Wagner
Keyword(s):  
Global Climate ◽  
Ice Core ◽  
Soil Formation ◽  
Late Glacial ◽  
The Arctic ◽  
Eastern European ◽  
Climate History ◽  
The North ◽  
Event Stratigraphy ◽  
Age Model

Abstract. Event-stratigraphical correlations between regional terrestrial sedimentary archives and marine or ice-core records that provide climate history are highly desirable for a deeper understanding of the effects of global climate change. However, such correlations are not simple, as the terrestrial records tend to be floating and fragmentary, and usually show varying sedimentation rates. Therefore, a reliable chronometric framework is a prerequisite for any event stratigraphy involving terrestrial archives. We propose that the age model underlying the event-stratigraphical approach for the eastern European key loess section at Stayky in Ukraine needs revision. Here we explore why it is unlikely that the Middle Pleniglacial Vytachiv Soil developed during Greenland interstadial (GIS) 8, and why the embryonic soils in the upper part of the Upper Pleniglacial part of the loess section most likely post-date the Heinrich 2 event. As a consequence, the revised age-model challenges the earlier suggested correlation of the suite of incipient soils above the Vytachiv Soil with Greenland Interstadials, which was supposed to start with GIS7 but for which matching from after GIS5 seems more likely. The revised chronology suggests that the transition from Middle to Upper Pleniglacial environmental conditions at the eastern European key section occurred during the final phase of marine isotope stage (MIS) 3. Thus, the picture appears to be in accordance with that of the western European key section at Nussloch. This points to a common driver of palaeo-environmental change in both regions, such as early late glacial maximum (LGM) advances of the Arctic ice shield or changes of the North Atlantic circulation and sea-ice distribution associated with changes in the palaeowind field relevant to aeolian loess deposition and soil formation. To test and substantiate the alternative age model, more chronologies for well-stratified loess sections throughout the European loess belt are required.

The Eem Stable Isotope Record along the GRIP Ice Core and Its Interpretation

1995 ◽  
Vol 43 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Sigfus J. Johnsen ◽  
Henrik B. Clausen ◽  
Willi Dansgaard ◽  
Niels S. Gundestrup ◽  
Claus U. Hammer ◽  
...  
Keyword(s):  
Stable Isotope ◽  
North Atlantic Ocean ◽  
Ice Core ◽  
Greenland Ice Sheet ◽  
High Sensitivity ◽  
Arctic Region ◽  
Conclusive Evidence ◽  
The Arctic ◽  
Ocean Current ◽  
The North

AbstractA 3029-m-long deep ice core extending nearly to bedrock has been drilled at the very top of the Greenland ice sheet (Summit) by the Greenland Ice-core Project (GRIP), an international European joint effort organized by the European Science Foundation. The ice core reaches back to 250,000 yr B.P. according to dating based partly on stratigraphic methods and partly on ice-flow modeling. A continuous and detailed stable isotope (δ18O) profile along the entire core depicts dramatic temperature changes in Greenland through the last two glacial cycles, including abrupt climatic shifts during the Eem/Sangamon Interglaciation, which is elsewhere recorded as a warm and stable period. The stratigraphic continuity of the Eemian layers has therefore been scrutinized. New ice core studies, comprising cloudy band observations, deconvolution, and frequency analyses, lead to the conclusion that the climate instability suggested during the Eem Interglaciation in Greenland is likely to be real, though no conclusive evidence is available. Whereas latitudinal displacements of the North Atlantic Ocean current are considered the immediate cause of the glacial climate instability, longitudinal displacements may be the immediate cause of the Eemian instability. If so, the Eemian climate changes will be much subdued outside the Arctic region and will probably only be recognizable in sedimentary sequences of high sensitivity and temporal resolution.

scholarly journals Geochronological reconsiderations for the Eastern European key loess section at Stayky in Ukraine

2013 ◽  
Vol 9 (3) ◽  
pp. 2629-2659 ◽  
Author(s):  
A. Kadereit ◽  
G. A. Wagner
Keyword(s):  
Global Climate ◽  
Ice Core ◽  
Late Glacial ◽  
The Arctic ◽  
Eastern European ◽  
Climate History ◽  
The North ◽  
Event Stratigraphy ◽  
Age Model ◽  
Arctic Ice

Abstract. Event-stratigraphical correlations between local/regional terrestrial sedimentary archives and marine or ice-core records providing the global climate history and time-scale are highly desirable for a deeper understanding of the effects of global climate change on a local/regional (palaeo-)environment. However, such correlations are not trivial, as the terrestrial records tend to be floating and fragmentary and usually show varying sedimentation rates. Therefore, a reliable chronometric framework is a necessary prerequisite for any event-stratigraphy involving terrestrial archives. In this respect, the age-model underlying the event-stratigraphical approach for the Eastern European key loess section at Stayky in Ukraine appears to need revision. Here we explain, why it is highly unlikely that the Middle Pleniglacial Vytachiv Soil developed during Greenland interstadial (GIS) 8, and why the embryonic soils in the upper part of the Upper Pleniglacial part of the loess section most likely post-date Heinrich 2 event. As a consequence, the revised age-model challenges the earlier suggested correlation of the suite of incipient soils above the Vytachiv Soil with Greenland Interstadials, which was supposed to start with GIS7 but for which matching from after GIS5 seems more likely. The revised chronology suggests that the transition from Middle to Upper Pleniglacial environmental conditions at the Eastern European key section occurred during the final phase of marine isotope stage (MIS) 3. Thus, the picture appears to be in accordance with that of the Western European key section at Nussloch in Germany pointing to a common driver of palaeo-environmental change in both regions, such as early Late Glacial Maximum (LGM) advances of the Arctic ice-shield or changes of the North Atlantic circulation and sea-ice distribution leading also to relevant changes of the palaeowind field.

scholarly journals Export of calcium carbonate corrosive waters from the East Siberian Sea

2016 ◽  
Author(s):  
Leif G. Anderson ◽  
Jörgen Ek ◽  
Ylva Ericson ◽  
Christoph Humborg ◽  
Igor Semiletov ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Sea Ice ◽  
North Atlantic Ocean ◽  
The Arctic ◽  
High Pco2 ◽  
Low Oxygen ◽  
Saturation State ◽  
Ice Melt ◽  
The North ◽  
Transformation Of Organic Matter

Abstract. The Siberian Shelf Seas are areas of extensive biogeochemical transformation of organic matter, both of marine and terrestrial origin. This in combination with brine production from sea ice formation results in a cold bottom water of relative high salinity and partial pressure of carbon dioxide (pCO2). Data from the SWERUS-C3 expedition compiled on the icebreaker Oden in July to September 2014 show the distribution of such waters at the outer shelf, as well as their export into the deep central Arctic basins. Very high pCO2 water, up to close to 1000 µatm, was observed associated with high nutrients and low oxygen concentrations. Consequently the saturation state of calcium carbonate was low, down to less than 0.8 for calcite and 0.5 for aragonite. Waters undersaturated in aragonite were also observed in the surface in waters at equilibrium with atmospheric CO2, however, at these conditions the cause of under-saturation was low salinity from river runoff and/or sea ice melt. The calcium carbonate corrosive water was observed all along the continental margin and well out into the deep Makarov and Canada Basins at a depth from about 50 m depth in the west to about 150 m in the east. These waters of low aragonite saturation state are traced in historic data to the Canada Basin and in the waters flowing out of the Arctic Ocean north of Greenland and in the western Fram Strait, thus potentially impacting the marine life in the North Atlantic Ocean.

scholarly journals Bacterial precursors and unsaturated long-chain fatty acids are biomarkers of North-Atlantic demosponges

2020 ◽  
Author(s):  
Anna de Kluijver ◽  
Klaas G.J. Nierop ◽  
Teresa M. Morganti ◽  
Martijn C. Bart ◽  
Beate M. Slaby ◽  
...  
Keyword(s):  
Fatty Acids ◽  
North Atlantic ◽  
Deep Sea ◽  
North Atlantic Ocean ◽  
Carbon Isotopic Composition ◽  
Building Blocks ◽  
Functional Ecology ◽  
The North ◽  
A Chain ◽  
Long Chain

AbstractSponges produce distinct fatty acids (FAs) that (potentially) can be used as chemotaxonomic and ecological biomarkers to study endosymbiont-host interactions and the functional ecology of sponges. Here, we present FA profiles of five common habitat-building deep-sea sponges (class Demospongiae, order Tetractinellida), which are classified as high microbial abundance (HMA) species. Geodia hentscheli, G. parva, G. atlantica, G. barretti, and Stelletta rhaphidiophora were collected from boreal and Arctic sponge grounds in the North-Atlantic Ocean. Bacterial FAs dominated in all five species and particularly isomeric mixtures of mid-chain branched FAs (MBFAs, 8- and 9-Me-C16:0 and 10 and 11-Me-C18:0) were found in high abundance (together ≥ 20% of total FAs) aside more common bacterial markers. In addition, the sponges produced long-chain linear, mid- and a(i)-branched unsaturated FAs (LCFAs) with a chain length of 24‒28 C atoms and had predominantly the typical Δ5,9 unsaturation, although also Δ9,19 and (yet undescribed) Δ11,21 unsaturations were identified. G. parva and S. rhaphidiophora each produced distinct LCFAs, while G. atlantica, G. barretti, and G. hentscheli produced similar LCFAs, but in different ratios. The different bacterial precursors varied in carbon isotopic composition (δ13C), with MBFAs being more enriched compared to other bacterial (linear and a(i)-branched) FAs. We propose biosynthetic pathways for different LCFAs from their bacterial precursors, that are consistent with small isotopic differences found in LCFAs. Indeed, FA profiles of deep-sea sponges can serve as chemotaxonomic markers and support the conception that sponges acquire building blocks from their endosymbiotic bacteria.

Climatic forcing of quaternary deep-sea benthic communities in the North Pacific Ocean

Paleobiology ◽  
2012 ◽  
Vol 38 (1) ◽  
pp. 162-179 ◽  
Author(s):  
Moriaki Yasuhara ◽  
Gene Hunt ◽  
Thomas M. Cronin ◽  
Natsumi Hokanishi ◽  
Hodaka Kawahata ◽  
...  
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
Climate Changes ◽  
North Atlantic Ocean ◽  
North Pacific Ocean ◽  
Environmental Drivers ◽  
Climatic Forcing ◽  
Shatsky Rise ◽  
The North ◽  
The North Pacific

There is growing evidence that changes in deep-sea benthic ecosystems are modulated by climate changes, but most evidence to date comes from the North Atlantic Ocean. Here we analyze new ostracod and published foraminiferal records for the last 250,000 years on Shatsky Rise in the North Pacific Ocean. Using linear models, we evaluate statistically the ability of environmental drivers (temperature, productivity, and seasonality of productivity) to predict changes in faunal diversity, abundance, and composition. These microfossil data show glacial-interglacial shifts in overall abundances and species diversities that are low during glacial intervals and high during interglacials. These patterns replicate those previously documented in the North Atlantic Ocean, suggesting that the climatic forcing of the deep-sea ecosystem is widespread, and possibly global in nature. However, these results also reveal differences with prior studies that probably reflect the isolated nature of Shatsky Rise as a remote oceanic plateau. Ostracod assemblages on Shatsky Rise are highly endemic but of low diversity, consistent with the limited dispersal potential of these animals. Benthic foraminifera, by contrast, have much greater dispersal ability and their assemblages at Shatsky Rise show diversities typical for deep-sea faunas in other regions.Statistical analyses also reveal ostracod-foraminferal differences in relationships between environmental drivers and biotic change. Rarefied diversity is best explained as a hump-shaped function of surface productivity in ostracods, but as having a weak and positive relationship with temperature in foraminifera. Abundance shows a positive relationship with both productivity and seasonality of productivity in foraminifera, and a hump-shaped relationship with productivity in ostracods. Finally, species composition in ostracods is influenced by both temperature and productivity, but only a temperature effect is evident in foraminifera. Though complex in detail, the global-scale link between deep-sea ecosystems and Quaternary climate changes underscores the importance of the interaction between the physical and biological components of paleoceanographical research for better understanding the history of the biosphere.

scholarly journals A review of the genus Iridogorgia (Octocorallia: Chrysogorgiidae) and its relatives, chiefly from the North Atlantic Ocean

2007 ◽  
Vol 87 (2) ◽  
pp. 393-402 ◽  
Author(s):  
Les Watling
Keyword(s):  
New Species ◽  
Atlantic Ocean ◽  
New England ◽  
North Atlantic ◽  
Deep Sea ◽  
New Genus ◽  
Growth Form ◽  
North Atlantic Ocean ◽  
The North ◽  
The North Atlantic

Exploration of the New England and Corner Rise Seamounts produced four new species of chrysogorgiid octocorals with the spiral iridogorgiid growth form. Three species are described as new in the genus Iridogorgia and one is described in the new genus Rhodaniridogorgia. Both genera have representatives in the Atlantic and Pacific Oceans. Iridogorgia magnispiralis sp. nov., is one of the largest octocorals encountered in the deep sea and seems to be widespread in the Atlantic.

First record of the rare deep-sea polychaete Rhamphobrachium (Rhamphobrachium) agassizii (Annelida: Onuphidae) in European waters

2020 ◽  
Vol 100 (5) ◽  
pp. 719-724
Author(s):  
Andrés Arias ◽  
Hannelore Paxton
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
North Atlantic Ocean ◽  
First Record ◽  
Polychaete Species ◽  
Azores Archipelago ◽  
The North ◽  
Deep Water Species ◽  
The North Atlantic ◽  
Water Species

AbstractRhamphobrachium (Rhamphobrachium) agassizii is reported from the Cantabrian Sea, Spain, from depths of 925–1207 m. This is its first record off the Iberian Peninsula and in European waters, representing its northernmost distribution in the North Atlantic Ocean to date. Previous reports of R. (R.) agassizii from the eastern and western North Atlantic demonstrate its apparent amphi-Atlantic distribution, which appears consistent with the distribution of the main Atlantic currents. It is a typical deep-water species with its deepest record at 2165 m from the Azores archipelago. The specimens were collected singly at two stations, attesting to the rarity of the species in contrast to its congener R. (Spinigerium) brevibrachiatum which was the most dominant polychaete species in a previous study.

Sign in / Sign up

Export Citation Format

Share Document