DOCSLIB.ORG

Last Interglacial Arctic Warmth Confirms Polar

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Last Interglacial Arctic Warmth Confirms Polar ARTICLE IN PRESS Quaternary Science Reviews 25 (2006) 1383–1400 Last Interglacial Arctic warmth confirms polar amplification of climate change CAPE-Last Interglacial Project MembersÃ,1 Received 15 June 2005; accepted 23 January 2006 Abstract The warmest millennia of at least the past 250,000 years occurred during the Last Interglaciation, when global ice volumes were similar to or smaller than today and systematic variations in Earth’s orbital parameters aligned to produce a strong positive summer insolation anomaly throughout the Northern Hemisphere. The average insolation during the key summer months (M, J, J) was ca 11% above present across the Northern Hemisphere between 130,000 and 127,000 years ago, with a slightly greater anomaly, 13%, over the Arctic. Greater summer insolation, early penultimate deglaciation, and intensification of the North Atlantic Drift, combined to reduce Arctic Ocean sea ice, allow expansion of boreal forest to the Arctic Ocean shore across vast regions, reduce permafrost, and melt almost all glaciers in the Northern Hemisphere. Insolation, amplified by key boundary condition feedbacks, collectively produced Last Interglacial summer temperature anomalies 4–5 1C above present over most Arctic lands, significantly above the average Northern Hemisphere anomaly. The Last Interglaciation demonstrates the strength of positive feedbacks on Arctic warming and provides a potentially conservative analogue for anticipated future greenhouse warming. r 2006 Elsevier Ltd. All rights reserved. 1. Introduction Here we present quantitative estimates of circum-Arctic LIG summer air and sea-surface temperatures recon- Planetary warm times in the recent geological past structed from proxy records preserved in terrestrial and inform the debate over Earth’s response to the continuing marine archives. These reconstructions demonstrate that build up of radiatively active atmospheric trace gases. Arctic summer air temperatures averaged ca 4–5 1C above Strong positive feedbacks in the Arctic are expected to present for most of the Arctic, well above the planetary amplify future greenhouse warming (Holland and Bitz, LIG average, although with coherent spatial patterns in the 2003), but the cumulative effect of these feedbacks remains magnitude of warmth. Arctic summers were warm enough debated (Serreze and Francis, 2006). Past planetary warm to melt all glaciers below 5 km elevation except the times provide a testing ground for the debate over polar Greenland Ice Sheet, which was reduced by ca 20–50% amplification of climate change. During the Last Inter- (Cuffey and Marshall, 2000; Otto-Bliesner et al., 2006). In glaciation (LIG) Earth was warmer than at any time in at addition, the margins of permanent Arctic Ocean sea ice least the past 250,000 years, with global temperatures retracted well into the Arctic Ocean basin and boreal 0–2 1C above present (e.g., CLIMAP Project Members, forests advanced to the Arctic Ocean coast across vast 1984; Bauch and Erlenkeuser, 2003). Circum-Arctic regions of the Arctic currently occupied by tundra, warming is recognized to have been substantial during although the central Arctic Ocean basin remained covered the LIG (Lauritzen and Anderson, 1995), but quantitative by permanent sea ice (Spielhagen et al., 2004). These reconstructions for this region are lacking. boundary condition changes reduced Earth’s albedo and altered the exchange of heat, moisture and trace gases ÃCorresponding author. G.H. Miller. Tel.: +1 303 492 6962. between the land, ocean and atmosphere, collectively E-mail address: [email protected]. amplifying insolation-driven (Fig. 1) circum-Arctic inter- 1A full list of authors appears in Appendix A. glacial warmth. 0277-3791/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.quascirev.2006.01.033 ARTICLE IN PRESS 1384 CAPE-Last Interglacial Project Members / Quaternary Science Reviews 25 (2006) 1383–1400 sea level reached present, and certainly was over long before sea level fell below present ca 116 ka (Zagwijn, 1996; Grøsfjeld et al., 1996). Despite these modest temporal differences, sea level provides a powerful tool for correlat- ing the LIG across much of the globe, and associated coral reefs offer the most secure dating of the LIG. The LIG has received less attention in the Arctic than at mid-latitudes, largely because of difficult access and paucity of sites. A decade ago, a circum-Arctic summary confirmed that the LIG was warmer than present (Lauritzen and Anderson, 1995), although quantitative estimates of warmth were not then possible. In the intervening decade, many new sites have been described from both marine and terrestrial archives, systematic recovery of sea-floor sediment from the Arctic Ocean has provided new evidence for the state of the polar ocean during the LIG, and new training sets, coupled to improved statistical tools, allow more precise quantifica- tion of many climate proxies (ter Braak and Juggins, 1993; Birks, 1998). For many Arctic regions, reliable transfer functions for summer temperatures are now available for Fig. 1. Monthly insolation anomalies (deviations from the present) for the pollen, chironomids, diatoms, dinoflagellates, planktonic time periods from 25 ka to present (upper panel) and from 140 to 115 ka and benthonic foraminifera, alkenones, and several ice- (lower panel) at 651N, showing the larger insolation anomaly for the Last core parameters. Consequently, it is now possible to Interglaciation relative to the present interglaciation. Anomalies are expressed as W mÀ2; time is in thousands of years before present. describe quantitatively at least some aspects of the LIG climate in the Arctic. 2. The Last Interglaciation 3. Methods The LIG was recognized more than a century ago in 3.1. Dating the Last Interglaciation northern Europe (Harting, 1875). Subsequently, it was defined from pollen records as the Eemian, a time of We capitalize on the uniqueness of the Late Quaternary deciduous forests bounded by periods of tundra (Jessen climate record and recent advances in geochronology to and Milthers, 1928). A half-century later, the Eemian was define LIG sites with reasonable certainty. Arctic sites with correlated with marine isotope stage (MIS) 5 (Emiliani, continuous accumulation since the LIG demonstrate that 1955), and eventually with the much shorter MIS 5e only the LIG shows evidence of summer temperatures (Shackleton, 1969; Mangerud et al., 1979; Shackleton et al., comparable to, or higher than the Holocene. Materials 2002). The LIG was securely placed in an absolute time suitable for high-precision U/Th analyses are rare in the frame when correlated to coral terraces on stable platforms Arctic, but advances in trapped-charge dating (optically that were amenable to high-precision uranium-series dating stimulated luminescence, infra-red-stimulated lumines- (Broecker and Van Donk, 1970; Gallup et al., 2002). We cence, thermoluminescence) provide independent verifica- define the LIG temporally as the penultimate interval of tion of LIG ages for many sites, although the dates often minimum global ice volume, when sea level was at or above lack sufficient precision to subdivide the interglaciation present. It is now widely accepted that sea level reached (Berger and Anderson, 2000; Murray and Funder, 2003). modern levels 13072 ka (thousands of years ago), and Diagnostic tephra, especially in Alaska and the Nordic remained at or above this level until the inception of the Seas, provide additional temporal constraint (Haflidason last glaciation, as ice grew on the continents ca 116 ka et al., 2000; Bege´ t and Keskinen, 2003; Rasmussen et al., (Stirling et al., 1998; Henderson and Slowey, 2000; 2003a, b). LIG sites (Tables 1 and 2) are identified with Mcculloch and Esat, 2000; Gallup et al., 2002; Muhs moderate to high certainty by a combination of strati- et al., 2002). Although we use the term LIG as broadly graphic position, climate proxies, absolute dating, and correlative with both the Eemian and MIS 5e, we recognize relationship to stratigraphic marker horizons (e.g. diag- that these intervals are not precisely correlative. The first nostic tephra). half of the LIG coincides with an unusually strong Northern Hemisphere positive summer insolation anom- 3.2. Quantifying Last Interglacial summer temperatures aly, whereas summer insolation receipts are relatively low through the later half of the marine highstand (Fig. 1). At high northern latitudes, summer temperatures exert Peak Eemian warmth may have occurred slightly before the dominant control on glacier mass balance, unless ARTICLE IN PRESS CAPE-Last Interglacial Project Members / Quaternary Science Reviews 25 (2006) 1383–1400 1385 Table 1 Published sites with quantitative summer temperature estimates for peak LIG warmth from terrestrial sites around the circum-Arctic. Details of site location and reconstruction techniques are provided in the references cited. Some key cites with important qualitative LIG summer or winter temperature or precipitation are also included Proxy DT ( 1C) DT (1C) Ppt Reference Comments Summer Winter Scandinavia Finland Treeline position Warmer (Saarnisto et al., 1999) Boreal forest north of reconstructed from present limit; birch at pollen Arctic Ocean shore. Russia European Russia Pollen, plant 4(Devyatova, 1982) Boreal forest north of macrofossils (Grichuk, 1984) present limit. West central Siberia Pollen, plant 6 to 8 5 to 7 Wetter (Gudina et al., 1983) Boreal forest 800 km macrofossils (Grichuk, 1984) north of present
Load more

Recommended publications
  • The Eemian - Local Sequences, Global Perspectives: Introduction
    Geologie en Mijnbouw / Netherlands Journal of Geosciences 79 (2/3): 129-133 (2000) The Eemian - local sequences, global perspectives: introduction Thijs van Kolfschoten1 & Philip L. Gibbard2 1 Faculty of Archaeology, Leiden University, P.O. Box 9515, 2300 RA LEIDEN, the Netherlands; Corresponding author; e-mail: [email protected] 2 Godwin Institute of Quaternary Research, Department of Geography, University of Cambridge, Downing Street, CAMBRIDGE CB2 3EN, England; e-mail:[email protected] Received: May 2000; accepted in revised form: 20 June 2000 G The history of this special issue gation and discussion on the Middle/Late Pleistocene boundary on the original type area of the Eemian in The history of this volume goes back to a 1973 IN- the Netherlands. The Eemian sequence was often QUA congress in New Zealand, where an INQUA used as reference and furthermore the term 'Eemian' Commission of Stratigraphy working group on major was widely used to identify the last interglacial far be­ subdivisions of the Pleistocene was established. The yond western central Europe. Examination of the Pleistocene series/epoch was hitherto generally subdi­ available data from the Eemian type area showed that vided into the Lower/Early, Middle and Upper/Late a re-evaluation of existing data and collection of criti­ Pleistocene (see, among others, Zeuner, 1935, 1959) cal new data were needed to define an unambiguous but the boundaries between these subseries/sube- stratigraphical boundary. Although the identification pochs were not formally defined. The boundary be­ of boundaries is central to stratigraphical subdivision, tween the Early and Middle Pleistocene was, in the it is nevertheless the Eemian as an entity that is of European literature, put at the base of the Cromerian particular interest for understanding the development Complex (Zagwijn, 1963) or at the Brunhes/Matuya- of a complete interglacial cycle.
    [Show full text]
  • The History of Ice on Earth by Michael Marshall
    The history of ice on Earth By Michael Marshall Primitive humans, clad in animal skins, trekking across vast expanses of ice in a desperate search to find food. That’s the image that comes to mind when most of us think about an ice age. But in fact there have been many ice ages, most of them long before humans made their first appearance. And the familiar picture of an ice age is of a comparatively mild one: others were so severe that the entire Earth froze over, for tens or even hundreds of millions of years. In fact, the planet seems to have three main settings: “greenhouse”, when tropical temperatures extend to the polesand there are no ice sheets at all; “icehouse”, when there is some permanent ice, although its extent varies greatly; and “snowball”, in which the planet’s entire surface is frozen over. Why the ice periodically advances – and why it retreats again – is a mystery that glaciologists have only just started to unravel. Here’s our recap of all the back and forth they’re trying to explain. Snowball Earth 2.4 to 2.1 billion years ago The Huronian glaciation is the oldest ice age we know about. The Earth was just over 2 billion years old, and home only to unicellular life-forms. The early stages of the Huronian, from 2.4 to 2.3 billion years ago, seem to have been particularly severe, with the entire planet frozen over in the first “snowball Earth”. This may have been triggered by a 250-million-year lull in volcanic activity, which would have meant less carbon dioxide being pumped into the atmosphere, and a reduced greenhouse effect.
    [Show full text]
  • Late Pleistocene Climate Change and Its Impact on Palaeogeography of the Southern Baltic Sea Region
    Late Pleistocene climate change and its impact on palaeogeography of the southern Baltic Sea region Leszek Marks Polish Geological Institute–National Research Institute, Warsaw, Poland Department of Climate Geology, University of Warsaw, Warsaw, Poland Main items • Regional bakground for climatic impact of the Eemian sea • Outline of Eemian climate changes in the adjoining terrestrial area • Principles of Central European climate during the last glacial stage • Climate change at the turn of Pleistocene and Holocene Surface hydrography of the Baltic Sea PRESENT EEMIAN SALINITY OF SURFACE WATER: dark blue – >30‰, light blue – 25-30‰, brown – 15-25‰, yellow – 5-15‰, red – <5‰ CURRENTS INDICATED BY ARROWS: red – warm surface current, blue – cold bottom current, green – brackish surface current (≈10‰), stripped red/yellow – coastal water surface current (>15‰), yellow – major source of river runoff Funder 2002) Eemian sea in the Lower Vistula Valley Region Cierpięta research borehole Cierpięta Makowska (1986), modified Chronology of Eemian based on pollen stratigraphy RPAZ after Mamakowa (1988, 1989) Head et al. (2005) Correlation of Eemian LPAZ with RPAZ in southern Baltic region Knudsen et al. (2012) Chronology of Eemian sea in southern Baltic region Top of Eemian deposits ca. 8500–11 000 yrs Boundary E5/E6 7000 lat Top of marine Eemian deposits Boundary E4/E5 3000 yrs Boundary E3/E4 750 yrs Boundary E2/E3 300 yrs E1 or E2 <300 yrs Bottom of marine Eemian deposits Boundary Saalian/Eemian 0 (126 ka BP) Based on correlation with regional pollen
    [Show full text]
  • Greenland Climate Simulations Show High Eemian Surface Melt Which Could Explain Reduced Total Air Content in Ice Cores
    Clim. Past, 17, 317–330, 2021 https://doi.org/10.5194/cp-17-317-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Greenland climate simulations show high Eemian surface melt which could explain reduced total air content in ice cores Andreas Plach1,2,3, Bo M. Vinther4, Kerim H. Nisancioglu1,5, Sindhu Vudayagiri4, and Thomas Blunier4 1Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway 2Department of Meteorology and Geophysics, University of Vienna, Vienna, Austria 3Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland 4Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark 5Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway Correspondence: Andreas Plach ([email protected]) Received: 27 July 2020 – Discussion started: 18 August 2020 Revised: 27 November 2020 – Accepted: 1 December 2020 – Published: 29 January 2021 Abstract. This study presents simulations of Greenland sur- 1 Introduction face melt for the Eemian interglacial period (∼ 130000 to 115 000 years ago) derived from regional climate simula- tions with a coupled surface energy balance model. Surface The Eemian interglacial period (∼ 130000 to 115 000 years melt is of high relevance due to its potential effect on ice ago; hereafter ∼ 130 to 115 ka) was the last period with a core observations, e.g., lowering the preserved total air con- warmer-than-present summer climate on Greenland (CAPE tent (TAC) used to infer past surface elevation. An investi- Last Interglacial Project Members, 2006; Otto-Bliesner et al., gation of surface melt is particularly interesting for warm 2013; Capron et al., 2014).
    [Show full text]
  • Late Quaternary Changes in Climate
    SE9900016 Tecnmcai neport TR-98-13 Late Quaternary changes in climate Karin Holmgren and Wibjorn Karien Department of Physical Geography Stockholm University December 1998 Svensk Kambranslehantering AB Swedish Nuclear Fuel and Waste Management Co Box 5864 SE-102 40 Stockholm Sweden Tel 08-459 84 00 +46 8 459 84 00 Fax 08-661 57 19 +46 8 661 57 19 30- 07 Late Quaternary changes in climate Karin Holmgren and Wibjorn Karlen Department of Physical Geography, Stockholm University December 1998 Keywords: Pleistocene, Holocene, climate change, glaciation, inter-glacial, rapid fluctuations, synchrony, forcing factor, feed-back. This report concerns a study which was conducted for SKB. The conclusions and viewpoints presented in the report are those of the author(s) and do not necessarily coincide with those of the client. Information on SKB technical reports fromi 977-1978 {TR 121), 1979 (TR 79-28), 1980 (TR 80-26), 1981 (TR81-17), 1982 (TR 82-28), 1983 (TR 83-77), 1984 (TR 85-01), 1985 (TR 85-20), 1986 (TR 86-31), 1987 (TR 87-33), 1988 (TR 88-32), 1989 (TR 89-40), 1990 (TR 90-46), 1991 (TR 91-64), 1992 (TR 92-46), 1993 (TR 93-34), 1994 (TR 94-33), 1995 (TR 95-37) and 1996 (TR 96-25) is available through SKB. Abstract This review concerns the Quaternary climate (last two million years) with an emphasis on the last 200 000 years. The present state of art in this field is described and evaluated. The review builds on a thorough examination of classic and recent literature (up to October 1998) comprising more than 200 scientific papers.
    [Show full text]
  • The Sangamonian Stage and the Laurentide Ice Sheet Le Sangamonien Et La Calotte Glaciaire Laurentidienne Die Sangamonische Zeit Und Die Laurentische Eisdecke Denis A
    Document généré le 4 oct. 2021 02:19 Géographie physique et Quaternaire The Sangamonian Stage and the Laurentide Ice Sheet Le Sangamonien et la calotte glaciaire laurentidienne Die sangamonische Zeit und die laurentische Eisdecke Denis A. St-Onge La calotte glaciaire laurentidienne Résumé de l'article The Laurentide Ice Sheet La présente revue des travaux sur le Sangamonien (jusqu'à juin 1986) effectués Volume 41, numéro 2, 1987 dans des régions clés démontre qu'il n'y a pas encore de réponse satisfaisante à la question suivante: « À quel moment la glace, qui allait devenir la calotte URI : https://id.erudit.org/iderudit/032678ar glaciaire laurentidienne, a-t-elle commencer à s'accumuler? » Dans la plupart DOI : https://doi.org/10.7202/032678ar des régions, la séquence stratigraphique ne fait que signaler l'existence probable d'une période interglaciaire, sans toutefois permettre de déterminer le moment où la glace a commencé à s'accumuler après l'intervalle climatique Aller au sommaire du numéro chaud. Il existe toutefois quelques indices. Les sédiments d'un delta glaciolacustres de la Formation de Scarborough, dans la région de Toronto, et le Till de Bécancour, dans la région de Trois-Rivières, datent probablement du Éditeur(s) Sangamonien (sous-phases isotopiques marines 5d-b). Le Till d'Adam, dans les basses terres de la baie James, leur est probablement corrélatif. Dans les Les Presses de l'Université de Montréal régions atlantiques du Canada, en particulier à l'île du Cap-Breton, des restes de plantes indiquent que le climat au cours du Sangamonien moyen aurait été ISSN très semblable à celui de la période de 11 000 à 12 000 ans BP.
    [Show full text]
  • Y of the Eemian Baltic Sea Discoveries in GEOLOGIAN TUTKIMUSKESKUS GEOLOGICAL SURVEY of FINLAND Tutkimusraportti 102 Report of Investigation 102
    TUTKIMUSRAPORTTI REPORT OF INVESTIGATION 102 y of the Eemian Baltic Sea discoveries in GEOLOGIAN TUTKIMUSKESKUS GEOLOGICAL SURVEY OF FINLAND Tutkimusraportti 102 Report of Investigation 102 Tuulikki Gränlund THE DIATOM STRATIGRAPHY OF THE EEMIAN BALTIC SEA ON THE BASIS OF SEDIMENT DISCOVERIES IN OSTROBOTHNIA, FINLAND Espoo 1991 Grönlund, T. 1991. The diatom stratigraphy of the Eemian Baltic Sea on the basis of sediment discoveries in Ostrobothnia, Finland. Geological Survey of Finland, Report of Investigation 102, 26 pages and 16 figures. Sediments from interglacial sites in Ostrobothnia, western Finland have been in­ vestigated for their diatom content. All the sites are correlated with the Eemian interglacial stage. The diatom successions of two of the sites, Norinkylä (Teuva) and Viitala (Perä• seinäjoki), begin with freshwater diatoms indicating deposition in a freshwater (great lake) basin. A rich marine diatom flora is found overlying the sediments with fresh­ water diatoms. The other sites Evijärvi, Ollala (Haapavesi) and Ukonkangas (Kär• sämäki), have also a similar marine flora with Grammatophora oceanica, Hyalodiscus scoticus, Paralia sulcata and Rhabdonema arcuatum as dominant species . The flora also includes many diatoms that mainly thrive in highly saline water and have not been found in Finland earlier. In the Ollala and Norinkylä deposits, there is a tran­ sition from marine to freshwater diatoms implying isolation from the sea. The marine deposits at the sites are interpreted as having been deposited in the Eemian Baltic Sea, and the freshwater sediments found beneath the marine deposits in a lake which occupied the Baltic basin and preceded the Eemian Baltic Sea. The history of the Eem!an Baltic Sea is discussed and a comparison is also made with the Holocene Baltic basin.
    [Show full text]
  • Greenland Climate Simulations Show High Eemian Surface Melt Andreas Plach1, 2, 3, Bo M
    https://doi.org/10.5194/cp-2020-101 Preprint. Discussion started: 18 August 2020 c Author(s) 2020. CC BY 4.0 License. Greenland climate simulations show high Eemian surface melt Andreas Plach1, 2, 3, Bo M. Vinther4, Kerim H. Nisancioglu1, 5, Sindhu Vudayagiri4, and Thomas Blunier4 1Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway 2Department of Meteorology and Geophysics, University of Vienna, Austria 3Climate and Environmental Physics, Physics Institute, University of Bern, Switzerland 4Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Denmark 5Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway Correspondence: Andreas Plach ([email protected]) Abstract. This study presents simulations of Greenland surface melt for the Eemian interglacial period (~130000 to 115000 years ago) derived from regional climate simulations with a coupled surface energy balance model. Surface melt is of high relevance for ice core records because it can influence observations, e.g., lower the preserved total air content (TAC) used to infer past surface elevation. An investigation of surface melt is particularly interesting for warm periods, such as the Eemian interglacial 5 period, with enhanced surface melt. Furthermore, Eemian ice is the deepest and most compressed ice preserved on Greenland, which means that melt layers can not be identified visually. Therefore, a knowledge of potential melt layers would be advan- tageous. The simulations presented here show Eemian surface melt at all deep Greenland ice core locations. Estimated TAC, based on simulated melt during the Eemian, could explain the lower TAC observations: at the summit of Greenland (GRIP) a refreezing ratio of more than 25 % of the annual accumulation is simulated.
    [Show full text]
  • The Eemian Mammal Fauna of Central Europe
    Geologie en Mijnbouw / Netherlands Journal of Geosciences 79 (2/3): 269-281 (2000) The Eemian mammal fauna of central Europe Th. van Kolfschoten1 1 Faculty of Archaeology, Leiden University, P.O. Box 9515, 2300 RA LEIDEN, the Netherlands; e-mail:[email protected] "T^ W Received: 15 May 2000; accepted in revised form: 31 May 2000 _X_ ^1 ft Abstract The knowledge of the Eemian fauna of central Europe is based on the fossil record from a number of sites located in the east­ ern part of Germany. The faunas with different deer species as well as Sus scrofa, Palaeoloxodon antiquus, Stephanorhinus kirch- bergensis and Glis glis indicate a forested environment alternating during the climatic optimum of the Eemian s.s. with areas with a more open environment inhabited by species such as Cricetus cricetus, Equus sp. (or Equus taubachensis), Equus hydrunti- nus and Stephanorhinus hemitoechus. Characteristic for the Rhine valley fauna are Hippopotamus amphibius and the water buffa­ lo (Bubalus murrensis); both species are absent in the eastern German faunas with an Eemian age. Taking into account the short period of time covered by the Eemian s.s., the amount of data on the Eemian mammalian fauna is remarkably large. There is, however, still an ongoing debate on whether the stratigraphical position of a number of faunas are of Eemian or 'intra-Saalian' age. Furthermore, there are faunal assemblages or stratigraphically isolated finds re­ ferred to the Eemian without indisputable evidence. This is particularly the case in the Rhine valley, where most of the so- called Eemian fossils come from dredged assemblages.
    [Show full text]
  • The Last Interglacial-Glacial Cycle (MIS 5-2) Re-Examined Based on Long Proxy Records from Central and Northern Europe
    Technical Report TR-13-02 The Last Interglacial-Glacial cycle (MIS 5-2) re-examined based on long proxy records from central and northern Europe Karin F Helmens Department of Physical Geography and Quaternary Geology, Stockholm University October 2013 Svensk Kärnbränslehantering AB Swedish Nuclear Fuel and Waste Management Co Box 250, SE-101 24 Stockholm Phone +46 8 459 84 00 ISSN 1404-0344 Tänd ett lager: SKB TR-13-02 P, R eller TR. ID 1360839 The Last Interglacial-Glacial cycle (MIS 5-2) re-examined based on long proxy records from central and northern Europe Karin F Helmens Department of Physical Geography and Quaternary Geology, Stockholm University October 2013 This report concerns a study which was conducted for SKB. The conclusions and viewpoints presented in the report are those of the author. SKB may draw modified conclusions, based on additional literature sources and/or expert opinions. A pdf version of this document can be downloaded from www.skb.se. Abstract A comparison is made between five Late Pleistocene terrestrial proxy records from central, temper- ate and northern, boreal Europe. The records comprise the classic proxy records of La Grande Pile (E France) and Oerel (N Germany) and more recently obtained records from Horoszki Duże (E Poland), Sokli (N Finland) and Lake Yamozero (NW Russia). The Sokli sedimentary sequence from the central area of Fennoscandian glaciation has escaped major glacial erosion in part due to non-typical bedrock conditions. Multi-proxy studies on the long Sokli sequence drastically change classic ideas of glaciation, vegetation and climate in northern Europe during the Late Pleistocene.
    [Show full text]
  • Article Is financed by CNRS-INSU
    Clim. Past, 5, 615–632, 2009 www.clim-past.net/5/615/2009/ Climate © Author(s) 2009. This work is distributed under of the Past the Creative Commons Attribution 3.0 License. Terrestrial climate variability and seasonality changes in the Mediterranean region between 15 000 and 4000 years BP deduced from marine pollen records I. Dormoy1,2, O. Peyron1, N. Combourieu Nebout2, S. Goring3, U. Kotthoff4,5, M. Magny1, and J. Pross4 1Laboratory of Chrono-Environnement, UMR CNRS 6249, University of Franche-Comte,´ 16 route de Gray, 25030 Besanc¸on, France 2Laboratory of Sciences of Climate and Environment, UMR 1572 CEA-CNRS-UVSQ, domaine du CNRS, avenue de la Terrasse, 91198 Gif-sur-Yvette, France 3Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, V5A 1S6, Canada 4Institute of Geosciences, University of Frankfurt, Altenhoferallee¨ 1, 60438 Frankfurt, Germany 5Department of Geosciences, Hamburg University, Bundesstrasse 55, 20146 Hamburg, Germany Received: 26 January 2009 – Published in Clim. Past Discuss.: 27 February 2009 Revised: 14 September 2009 – Accepted: 15 September 2009 – Published: 19 October 2009 Abstract. Pollen-based climate reconstructions were per- Oscillations, 8.2 ka event, Bond events) connected to the formed on two high-resolution pollen marines cores from the North Atlantic climate system are documented in the Albo- Alboran and Aegean Seas in order to unravel the climatic ran and Aegean Sea records indicating that the climate oscil- variability in the coastal settings of the Mediterranean re- lations associated with the successive steps of the deglacia- gion between 15 000 and 4000 years BP (the Lateglacial, and tion in the North Atlantic area occurred in both the western early to mid-Holocene).
    [Show full text]
  • I3ll Sea-Level Indicators on Tectonically Stable Islands
    Journal of Coastal Research Fort Lauderdale, Florida Summer 1995 Sea-Level Highstand Chronology from Stable Carbonate Platforms (Bermuda and The Bahamas) Paul J. Hearty'[ and Pascal Kindler:j: tThe College of the Bahamas :j:Department de Geolologie et Cable Beach Villas #43 Paleontologie r.o. Box N-3723 Universite de Geneve Nassau, Bahamas 13, rue des Maraichers 1211 Geneve, Suisse ABSTRACT _ HEARTY, P.J. and KINDLER, P., 1995.Sea-level highstand chronology from stable carbonale platforms (Bermuda and The Bahamas). Journal of Coastal Research. 11(3), 675-689. Fort Lauderdale (Florida), ,tllllllll:. ISSN 0749-0208. e • •• • A history of sea-level highstands representing the past 1.2 my is assembled from geological and geo­ - --- ~ =...tIl- chronological data from Bermuda and the Bahamas. Outcrops of marine and eolian limestones exhibit f:!!I3ll sea-level indicators on tectonically stable islands. Because of the low-lying nature of the islands, they 2_ --a preserve a record of both highstand (limestone) aud lowstand (paleosol) events. Geomorphology and .... s-- sequence stratigraphy are critical for ranking deposit age, while U-series, amino acid racemization (AAR), electron spin resonance (ESR), and paleomagnetics have provided absolute and relative age estimates. In Bermuda, two early Pleistocene marine sequences are estimated to be >700 ka and >880 ka. The younger of the two is associated with a +22 m marine terrace cut into the older Walsingham Fm, which exposes marine limestones at < +5 m a.s.l. During the latter half of the middle Pleistocene (Stages 11, 9, and 7; 500 to 180 ka), sealevel rose above the present at least three times to approximately +4 m, +4 m, and +2.5 m, respectively.
    [Show full text]