DOCSLIB.ORG

Svendsen Et Al. 1996, Mangerud Et Al

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Svendsen Et Al. 1996, Mangerud Et Al The glacial history of the Svalbard archipelago from late Vistulian to the present time in late Holocene Authors: Joanna Ćwiąkała Mateusz Moskalik Piotr Zagórski [email protected] [email protected] [email protected] Instytut Geografii, Uniwersytet Pedagogiczny im. KEN w Krakowie Instytut Geofizyki Polskiej Akademii Nauk w Warszawie Wydział Nauk o Ziemi i Gospodarki Przestrzennej, Uniwersytet Marii Curie-Skłodowskiej w Lublinie Introduction: Aim and descriptions of tables: Due to the rich literature of the history of glaciation on Svalbard, it is The scientists often study the glacial history of the Svalbard archipelago, The main aim this study is to show this history only from the late difficult to collect the whole. The duration of the episodes in the left but the articles usually refer to a particular piece of Svalbard. The authors Vistulian to the present time. Stadials and interstadials vary start columns of both tables are generalized due to those differences. studied many of scientific articles based on the researches to find and time, duration in different places, according to various authors. In the table 1, authors have two divisions, as in the literature, this collect this history. Therefore, it is hard to collect all information and describe this history. period was highlighted as one (Bølling/OD/Allerød), or as three Because of these differences, the authors performed two summary separate short episodes. The first division is the general. Second Basic information: tables. The tables represent durations of these episodes in different division (Bølling – I, Older Dryas- II, Allerød – III), shows how Svalbard js located in the Arctic, at the edge of the continental shelf of places in the Svalbard archipelago, according to studies by different much the episode lasted at a given location according to data in the Europe. The end of shelf boundary occurrence of ice caps in the past authors. literature. glaciations. In turn, the main elements of the landscape of the archipelago The table 1 presents the results for the Late Vistulian. The table 2 are glaciers that are currently in a recession. Spitsbergen sets the limit of presents the results for the Holocene. The tables are demonstrative. In the Table 2, in part about Holocene Climatic Optimum, the short Pleistocene glaciations, and the current state of glaciers allows Of course you should return the note that these tables do not Holocene Cooling is marked by red color. This episode interrupted determining the place where the recession is intense. represent the whole. on about 200 years this Optimum. stadials/interstadials stadials/interstadial The duration of the area by various authors The duration of the area by various authors (duration BP) s (duration BP) - Spitsbergen, Billefjorden, Kongsfjorden around 1900 AD- now. (Svendsen et al. 2002, Plassen et al. 2003, - Svalbard 12 500-11 500 BP (Ślubowska-Woldengen et al. 2008, Sternal 2012), XX- century Szczuciński et al. 2009, Kempf et al. 2013) - Murchisonfjorden12 400-11 500 BP (Kaakinen et al. 2009, Ojala et al. 2014) warming (1900-now) - SW Spitsbergen 12 600 – 11 500 BP (Hald et al. 2007, Rasmussen et al. 2007, 2012) - Svalbard 1200-1900 AD (Gordiyenko et al. 1980, Svendsen, Mangerud 1997), - W Spitsbergen 10 900 BP the end of the last stage of Vistulian (Svendsen et al. 1996, Mangerud et al. 1998, Lønne 2005, Forwick, Vorren 2009), - S Spitsbergen 1300-1900 AD (Mangerud 1992b, 1997, Mangerud, Landvik 2007, Forwick et al. 2010), - Spitsbergen, around Isfjorden11 000- 10 000 BP (Svendsen et al. 1996), Little Ice Age Younger Dryas - Hornsund 1600-1900 AD (Majewski et al. 2009), - Isfjorden 12 800 – 11 700 BP (Mangerud et al. 1992, 1998, Svendsen et al. 1996, Forwick, Vorren 2009), (1300-1900 AD) (12 000-10 000 BP) - Billefjorden 1600-1900 AD (Szczuciński et al. 2009), - Billefjorden 11 000 – 10 000 BP (Svendsen et al. 1996); 11 000 – 9 7000 BP (Mangerud, Svendsen 1990), - Kongsfjorden-Krossfjorden 550 – 200 BP (Howe et al. 2003) - Van Mijenfjorden 12 800 – 11 700 BP (Mangerud et al. 1992, Hald et al. 2004), - Hornsund 1300-1600 AD (Majewski et al. 2009), Transitional period - Brommeldalen (around the Van Mijenfjorden) 10 500-10 100 (Mangerud, Svendsen 1990), between MWP and - Skilvika 11 000- 10 000 BP (Mangerud et al. 1998) LIA (1300-1600 AD) - Barents Sea15 000- 12 000 BP (Landvik et al. 1998), Medieval Warm - max. 800-1250 AD (Marsz 2009) - The shelf15 000-12 000 BP (Mangerud, Landvik 2007); start of the deglaciation of the SW shelf 20 500/19 500 BP (Rasmussen et al. 2007, Period (600-1300 Jessen et al. 2010), AD) -Svalbard 14 000 – 10 000 BP (Svendsen et al. 1996);14 500-13 500 BP (Ślubowska-Woldengen et al. 2008, Sternal 2012), X ? ? - W Spitsbergen 4000-2500 BP (Birks 1991, Svendsen, Mangerud 1997), (III)- Allerød - W Spitsbergen, coast 14 000-13 000/12 500 BP (Svendsen, Mangerud 1992b); (I) – Bølling 14 800 – 12 400 BP (Svendsen et al. 1996), - Van Keulenfjorden 4700-2000 BP (Birks 1991, Svendsen, Mangerud 1997, Hald et al. 2004, Rasmussen et al. (II)- Older Dryas - SW Spitsbergen 14 000- 12 600 BP (Hald et al. 2007, Rasmussen et al. 2007, 2012), 2012, Kempf et al. 2013), (I)- Bølling -Isfjorden (III) – Allerød 12 300 – 11 000 BP (Svendsen et al. 1996); (II)- Older Dryas 12 400 – 12 300 BP (Svendsen et al. 1996), Revdalen Stadial - Kaffiøyra 3000-2500 BP (Grześ 2009), - W and N Spitsbergen (Isfjorden, Kongsfjorden, Woodfjorden, Raudfjorden, Liefdefjorden, Smeerenburgfjorden) (II) – Older Dryas 12 600- (4000-2500 BP) (15 000-12 000 BP) - Billefjorden 2800 BP –start of the neoglacial (Szczuciński et al. 2009), 12 400 (Landvik et al. 1998), - Linnédalen, Isfjorden 3600/4000 – 2800/3000 BP (Svendsen, Mangerud 1997), - Kaffiøyra (13 000 -10 000 BP) (Grześ et al. 2009), - Hornsund 3000-2500 BP (Kowalewski 1991, Linder, Marks 1991), - Linnedalen 18 000/17 500 – 12 500 BP (Mangerud, Svendsen 1990, Mangerud et al. 1992) - N part of the Barents Sea 9500-5000 BP (Svendsen, Mangerud 1997), -Van Keulenfjorden (III) – Allerød 11 800 – 11 600 BP (Kempf et al. 2013) - Svalbard early Holocene 9500-7500 BP (Ślubowska-Woldengen et al. 2008, Sternal 2012), - Svalbard start 20 000 (Svendsen et al. 2004), - Nordaustlandet, N and W Spitsbergen 9500-3500 BP (Salvigsen et al. 2002), Last Glacial Maximum - around Nordaustlandet and Barents Sea start 18 000 BP (Solheim 1991), - Nordaustlandet start around10 000 BP (Solheim 1991), - Bjørnøya 9500-8000 BP, (6700- 8500 cal. BC) (Wohlfarth et al. 1995, Hald et al. 2004), 11 200 – 9300 BP (LGM) - N part of the ice sheet 23 000 - 21 000 BP (Siguardardottir 2011), Holocene Climatic (Wohlfarth et al. 1995), (23/22 000-15 000 BP) - the shelf 22 000 -15 000 BP (Landvik et al.1998), Optimum (10 000- - W Svalbard 9500- 3500 BP (Svendsen, Mangerud 1997), -18 000-15 000 BP (Landvik et al. 1998, Elverhøi et al. 1998) 4000 BP), in the - W Spitsbergen/continental margin 11 200- 8800 BP (Hald et al. 2004), -N part of The Barents Sea, Svalbard 30 000/25 000 - 10 000 BP (Mangerud et al. 1998) – based on the figure, meantime Cool - Van Mijenfjorden 11200-8800 BP (Hald et al. 2004), -Svalbard 29 000 - 22 000 BP (Lindner, Marks 1993a); start around 26 000 BP (Landvik et al. 1998), Holocene (8800- - Kongsfjorden, Krossfjorden 9500 - 4500 BP (Svendsen et al. 2002, Howe et al. 2003), - Svalbard - Barents Sea start - 27 000 BP, reach the shelf 22 000 BP, reach the edge of the shelf 18 000 BP (Dowdeswell et al. 1998), 8600 BP) – stadial Slaklidalen (29 000 - - Isfjorden 11 200-9000 BP (Forwick, Vorren 2009), Gronfjord ? 22 000 BP) – the start of - Nordaustlandet 25 000- 10 000 BP (Kaakinen et al. 2009) – based on the figure, - Central part of Spitsbergen 11 000-7500 BP (Hald et al. 2004), 9500-5000 BP (Salvigsen et al. 1990), the Late Vistulian - Spitsbergen start 25 000 BP (Landvik et al. 1987), -Van Keulenfjorden 10 660-6750 BP (Kempf 2011), - Kongsfjorden start around - 20 000 BP (Howe et al. 2003, Kehrl et al. 2011), Holocene Cooling: - 25 000-15 000 BP (Ingólfsson, Landvik 2013), - W part of the Barents Sea, part of Spitsbergen 9000-8800 BP (Forwick, Vorren 2009), - Van Mijenfjorden 8000/7500-4000 BP (Hald et al. 2004) Table 1. The distribution of the stadials/interstadials in late Vistulian on the Svalbard. Authors' own Table 2. The distribution of the stadials/interstadials in Holocene on the Svalbard. elaboration based on literature Authors' own elaboration based on literature THE EXTENT OF THE ICE SHEET IN THE LATE THE EXTENT OF THE ICE SHEET IN THE LATE VISTULIAN VISTULIAN BY VARIOUS AUTHORS: BY VARIOUS AUTHORS: Fig. 1. The extent of the ice sheet at the LGM Conlusions: Fig. 4. The extent of the glaciers in HCO- Early Holocene (9.5 - 7.5 ka By analyzing the history of glaciation of Svalbard from late Vistulian to the XXI- BP) century, you can play the glacial extents in different periods of time. The following contains the main points of the history of glaciation in Svalbard. The duration of each stadials/interstadials is rounded due to the fact, that the duration was significantly different in the different areas. The end of the Pleistocene - Late Vistulian period (25 000 - 10 000 years BP): 1) The Last Glacial Maximum (LGM)- (23 000 - 15 000 years BP) – During this maximum ice sheet reached its greatest extent. Its western edge ended up on the western continental shelf. Perhaps, in this period of time, it was connected to the Scandinavian ice sheet (Fig.1.). 2) Bølling/Older Dryas/Allerød - (15 000 - 12 800 years BP) - During this period the deglaciation of ice sheet Svalbard – Barents Sea took place (Fig.2.).
Load more

Recommended publications
  • The Last Maximum Ice Extent and Subsequent Deglaciation of the Pyrenees: an Overview of Recent Research
    Cuadernos de Investigación Geográfica 2015 Nº 41 (2) pp. 359-387 ISSN 0211-6820 DOI: 10.18172/cig.2708 © Universidad de La Rioja THE LAST MAXIMUM ICE EXTENT AND SUBSEQUENT DEGLACIATION OF THE PYRENEES: AN OVERVIEW OF RECENT RESEARCH M. DELMAS Université de Perpignan-Via Domitia, UMR 7194 CNRS, Histoire Naturelle de l’Homme Préhistorique, 52 avenue Paul Alduy 66860 Perpignan, France. ABSTRACT. This paper reviews data currently available on the glacial fluctuations that occurred in the Pyrenees between the Würmian Maximum Ice Extent (MIE) and the beginning of the Holocene. It puts the studies published since the end of the 19th century in a historical perspective and focuses on how the methods of investigation used by successive generations of authors led them to paleogeographic and chronologic conclusions that for a time were antagonistic and later became complementary. The inventory and mapping of the ice-marginal deposits has allowed several glacial stades to be identified, and the successive ice boundaries to be outlined. Meanwhile, the weathering grade of moraines and glaciofluvial deposits has allowed Würmian glacial deposits to be distinguished from pre-Würmian ones, and has thus allowed the Würmian Maximum Ice Extent (MIE) –i.e. the starting point of the last deglaciation– to be clearly located. During the 1980s, 14C dating of glaciolacustrine sequences began to indirectly document the timing of the glacial stades responsible for the adjacent frontal or lateral moraines. Over the last decade, in situ-produced cosmogenic nuclides (10Be and 36Cl) have been documenting the deglaciation process more directly because the data are obtained from glacial landforms or deposits such as boulders embedded in frontal or lateral moraines, or ice- polished rock surfaces.
    [Show full text]
  • A Possible Late Pleistocene Impact Crater in Central North America and Its Relation to the Younger Dryas Stadial
    A POSSIBLE LATE PLEISTOCENE IMPACT CRATER IN CENTRAL NORTH AMERICA AND ITS RELATION TO THE YOUNGER DRYAS STADIAL SUBMITTED TO THE FACULTY OF THE UNIVERSITY OF MINNESOTA BY David Tovar Rodriguez IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE Howard Mooers, Advisor August 2020 2020 David Tovar All Rights Reserved ACKNOWLEDGEMENTS I would like to thank my advisor Dr. Howard Mooers for his permanent support, my family, and my friends. i Abstract The causes that started the Younger Dryas (YD) event remain hotly debated. Studies indicate that the drainage of Lake Agassiz into the North Atlantic Ocean and south through the Mississippi River caused a considerable change in oceanic thermal currents, thus producing a decrease in global temperature. Other studies indicate that perhaps the impact of an extraterrestrial body (asteroid fragment) could have impacted the Earth 12.9 ky BP ago, triggering a series of events that caused global temperature drop. The presence of high concentrations of iridium, charcoal, fullerenes, and molten glass, considered by-products of extraterrestrial impacts, have been reported in sediments of the same age; however, there is no impact structure identified so far. In this work, the Roseau structure's geomorphological features are analyzed in detail to determine if impacted layers with plastic deformation located between hard rocks and a thin layer of water might explain the particular shape of the studied structure. Geophysical data of the study area do not show gravimetric anomalies related to a possible impact structure. One hypothesis developed on this works is related to the structure's shape might be explained by atmospheric explosions dynamics due to the disintegration of material when it comes into contact with the atmosphere.
    [Show full text]
  • Late Pleistocene Geochronology of European Russia
    [RADIOCARBON, VOL. 35, No. 3, 1993, P. 421-427] LATE PLEISTOCENE GEOCHRONOLOGY OF EUROPEAN RUSSIA KU. A. ARSLANOV Geographical Research Institute, St. Petersburg State University, St. Petersburg 199004 Russia 14C ABSTRACT. I constructed a Late Pleistocene geochronological scale for European Russia employing dating and paleo- botanical studies of several reference sections. MIKULIN0 (RISS-WURM) INTERGLACIAL AND EARLY VALDAI (EARLY WURM) STAGES AND INTERSTADIALS 230Th/ I employed a modified 4U dating method (Arslanov et al. 1976, 1978, 1981) to determine shell ages. I learned that 232Th is present only in the outer layer of shells; thus, it is not necessary to correct for 230Th if the surface (-30% by weight) is removed. A great many shells were parallel- dated by 14C and 23°Th/234U methods; results corresponded well for young shells (to 13-14 ka). Older shells appear to be younger due to recent carbonate contamination. Shells from transgression sediments of the Barents, White and Black Seas were chosen as most suitable for dating, based on appearance. Table 1 presents measured ages for these shells. The data show that the inner fractions of shells sampled from Boreal (Eem) transgression deposits of the Barents and White Seas date to 86-114 ka. Shells from sediments of the Black Sea Karangat transgression, which correlates to the Boreal, date to 95-115 ka. 23°Th/234U dating of shells and coral show that shells have younger ages than corals; this appears to result from later uranium penetration into shells (Arslanov et a1.1976). Boreal transgression sediments on the Kola peninsula can be placed in the Mikulino interglacial based on shell, microfauna, diatom and pollen studies (Arslanov et at.
    [Show full text]
  • Late Pleistocene California Droughts During Deglaciation and Arctic Warming
    ARTICLE IN PRESS EPSL-10042; No of Pages 10 Earth and Planetary Science Letters xxx (2009) xxx–xxx Contents lists available at ScienceDirect Earth and Planetary Science Letters journal homepage: www.elsevier.com/locate/epsl Late Pleistocene California droughts during deglaciation and Arctic warming Jessica L. Oster a,⁎, Isabel P. Montañez a, Warren D. Sharp b, Kari M. Cooper a a Geology Department, University of California, Davis, California, United States b Berkeley Geochronology Center, Berkeley, California, United States a r t i c l e i n f o a b s t r a c t Article history: Recent studies document the synchronous nature of shifts in North Atlantic regional climate, the intensity of Received 4 February 2009 the East Asian monsoon, and productivity and precipitation in the Cariaco Basin during the last glacial and Received in revised form 4 August 2009 deglacial period. Yet questions remain as to what climate mechanisms influenced continental regions far Accepted 7 October 2009 removed from the North Atlantic and beyond the direct influence of the inter-tropical convergence zone. Available online xxxx Here, we present U-series calibrated stable isotopic and trace element time series for a speleothem from Editor: P. DeMenocal Moaning Cave on the western slope of the central Sierra Nevada, California that documents changes in precipitation that are approximately coeval with Greenland temperature changes for the period 16.5 to Keywords: 8.8 ka. speleothem From 16.5 to 10.6 ka, the Moaning Cave stalagmite proxies record drier and possibly warmer conditions, Sierra Nevada paleoclimate signified by elevated δ18O, δ13C, [Mg], [Sr], and [Ba] and more radiogenic 87Sr/86Sr, during Northern deglacial Hemisphere warm periods (Bølling, early and late Allerød) and wetter and possibly colder conditions during stable and radiogenic isotopes Northern Hemisphere cool periods (Older Dryas, Inter-Allerød Cold Period, and Younger Dryas).
    [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]
  • Gabriola's Glacial Drift—An Icecap?
    Context: Gabriola ice-age geology Citation: Doe, N.A., Gabriola’s glacial drift—10. An icecap? SILT 8-10, 2014. <www.nickdoe.ca/pdfs/Webp530.pdf>. Accessed 2014 Jan 30. NOTE: Adjust the accessed date as needed. Copyright restrictions: Copyright © 2014. Not for commercial use without permission. Date posted: January 30, 2014. Author: Nick Doe, 1787 El Verano Drive, Gabriola, BC, Canada V0R 1X6 Phone: 250-247-7858 E-mail: [email protected] This is Version 3.7, the final version. Notes added on June 9, 2021: There is an error in the caption to the graph on page 15. The yellow dot on the left is for plant material, the older one on the right is for a log. It has been left uncorrected in this copy. Additional radiocarbon dates have been obtained since this article was published and these are recorded in detail in Addendum 2021 to SILT 8-13 <https://nickdoe.ca/pdfs/Webp533.pdf>. The new information affects some of the detail in this Version 3.7, particularly on page 15, but not significantly enough to justify an extensive rewrite and republishing of the article. Version 3.7 therefore remains unchanged. Version:3.7 Gabriola’s glacial drift—an icecap? Nick Doe Carlson, A. E. (2011) Ice Sheets and Sea Level in Earth’s Past. Nature Education Knowledge 3(10):3 The deglaciation of Gabriola what ways did the events of that time shape the landscape we see today? One snowy winter’s day, around the year 14 The two approaches adopted are radiocarbon 16000 BC (14.50 ka C BP), give or take a dating of sites that mark the transition from century or two, the ice under which Gabriola the late-Pleistocene to the early-Holocene was buried at that time, reached its 1 (ice age to post-ice age); and computer maximum thickness.
    [Show full text]
  • Quaternary Glaciations and Their Variations in Norway and on the Norwegian Continental Shelf
    Quaternary glaciations and their variations in Norway and on the Norwegian continental shelf Lars Olsen1, Harald Sveian1, Bjørn Bergstrøm1, Dag Ottesen1,2 and Leif Rise1 1Geological Survey of Norway, Postboks 6315 Sluppen, 7491 Trondheim, Norway. 2Present address: Exploro AS, Stiklestadveien 1a, 7041 Trondheim, Norway. E-mail address (corresponding author): [email protected] In this paper our present knowledge of the glacial history of Norway is briefly reviewed. Ice sheets have grown in Scandinavia tens of times during the Quaternary, and each time starting from glaciers forming initial ice-growth centres in or not far from the Scandes (the Norwegian and Swedish mountains). During phases of maximum ice extension, the main ice centres and ice divides were located a few hundred kilometres east and southeast of the Caledonian mountain chain, and the ice margins terminated at the edge of the Norwegian continental shelf in the west, well off the coast, and into the Barents Sea in the north, east of Arkhangelsk in Northwest Russia in the east, and reached to the middle and southern parts of Germany and Poland in the south. Interglacials and interstadials with moderate to minimum glacier extensions are also briefly mentioned due to their importance as sources for dateable organic as well as inorganic material, and as biological and other climatic indicators. Engabreen, an outlet glacier from Svartisen (Nordland, North Norway), which is the second largest of the c. 2500 modern ice caps in Norway. Present-day glaciers cover to- gether c. 0.7 % of Norway, and this is less (ice cover) than during >90–95 % of the Quater nary Period in Norway.
    [Show full text]
  • Alphabetical List
    LIST E - GEOLOGIC AGE (STRATIGRAPHIC) TERMS - ALPHABETICAL LIST Age Unit Broader Term Age Unit Broader Term Aalenian Middle Jurassic Brunhes Chron upper Quaternary Acadian Cambrian Bull Lake Glaciation upper Quaternary Acheulian Paleolithic Bunter Lower Triassic Adelaidean Proterozoic Burdigalian lower Miocene Aeronian Llandovery Calabrian lower Pleistocene Aftonian lower Pleistocene Callovian Middle Jurassic Akchagylian upper Pliocene Calymmian Mesoproterozoic Albian Lower Cretaceous Cambrian Paleozoic Aldanian Lower Cambrian Campanian Upper Cretaceous Alexandrian Lower Silurian Capitanian Guadalupian Algonkian Proterozoic Caradocian Upper Ordovician Allerod upper Weichselian Carboniferous Paleozoic Altonian lower Miocene Carixian Lower Jurassic Ancylus Lake lower Holocene Carnian Upper Triassic Anglian Quaternary Carpentarian Paleoproterozoic Anisian Middle Triassic Castlecliffian Pleistocene Aphebian Paleoproterozoic Cayugan Upper Silurian Aptian Lower Cretaceous Cenomanian Upper Cretaceous Aquitanian lower Miocene *Cenozoic Aragonian Miocene Central Polish Glaciation Pleistocene Archean Precambrian Chadronian upper Eocene Arenigian Lower Ordovician Chalcolithic Cenozoic Argovian Upper Jurassic Champlainian Middle Ordovician Arikareean Tertiary Changhsingian Lopingian Ariyalur Stage Upper Cretaceous Chattian upper Oligocene Artinskian Cisuralian Chazyan Middle Ordovician Asbian Lower Carboniferous Chesterian Upper Mississippian Ashgillian Upper Ordovician Cimmerian Pliocene Asselian Cisuralian Cincinnatian Upper Ordovician Astian upper
    [Show full text]
  • Major AC Excursions During the Late Glacial and Early Holocene
    Quaternary International 105 (2003) 71–76 Major D14C excursions during the late glacial and early Holocene: changes in ocean ventilation or solar forcing of climate change? Bas van Geela,*, Johannes van der Plichtb, Hans Renssenc a Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands b Centre for Isotope Research, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands c Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands We dedicate this paper to Thomas van der Hammen, one of the pioneers in the study of climate change during the Late Glacial period Abstract The atmospheric 14C record during the Late Glacial and the early Holocene shows sharp increases simultaneous with cold climatic 14 phases. These increases in the atmospheric C content are usually explained as the effect of reduced oceanic CO2 ventilation after episodic outbursts of large meltwater reservoirs into the North Atlantic. In this hypothesis the stagnation of the thermohaline circulation is the cause of both climate change as well as an increase in atmospheric 14C: As an alternative hypothesis we propose that changes in 14C production give an indication for the cause of the recorded climate shifts: changes in solar activity cause fluctuations in the solar wind, which modulate the cosmic ray intensity and related 14C production. Two possible mechanisms amplifying the changes in solar activity may result in climate change. In the case of a temporary decline in solar activity: (1) reduced solar UV intensity may cause a decline of stratospheric ozone production and cooling as a result of less absorption of sunlight.
    [Show full text]
  • Deglaciation of the Laurentide Ice Sheet from the Last Glacial Maximum
    Cuadernos de Investigación Geográfica ISSN 0211-6820 2017 Nº 43 (2) pp. 377-428 Geographical Research Letters eISSN 1697-9540 DOI: http://doi.org/10.18172/cig.3237 © Universidad de La Rioja DEGLACIATION OF THE LAURENTIDE ICE SHEET FROM THE LAST GLACIAL MAXIMUM C.R. STOKES* Department of Geography, Durham University, Durham, DH1 3LE, UK ABSTRACT. The last deglaciation of the Laurentide Ice Sheet (LIS) was associated with major reorganisations in the ocean-climate system and its retreat also represents a valuable analogue for understanding the rates and mechanisms of ice sheet collapse. This paper reviews the characteristics of the LIS at its Last Glacial Maximum (LGM) and its subsequent deglaciation, with particular emphasis on the pattern and timing of ice margin recession and the driving mechanisms of retreat. The LIS initiated over the eastern Canadian Arctic ~116-110 ka (MIS 5d), but its growth towards the LGM was highly non-linear and punctuated by several episodes of expansion (~65 ka: MIS 4) and retreat (~50-40 ka: MIS 3). It attained its maximum position around 26-25 ka (MIS 2) and existed for several thousand years as an extensive ice sheet with major domes over Keewatin, Foxe Basin and northern Quebec/Labrador. It extended to the edge of the continental shelf at its marine margins and likely stored a sea-level equivalent of around 50 m and with a maximum ice surface ~3000 m above present sea-level. Retreat from its maximum was triggered by an increase in boreal summer insolation, but areal shrinkage was initially slow and the net surface mass balance was positive, indicating that ice streams likely played an important role in reducing the ice sheet volume, if not its extent, via calving at marine margins.
    [Show full text]
  • A Study of Scale Effect on Specific Sediment Yield in the Loess Plateau
    中国科技论文在线 http://www.paper.edu.cn Melt-Water-Pulse (MWP) events and abrupt climate change of the last deglaciation HUANG EnQing† & TIAN Jun State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China The last deglaciation is characterized by massive ice sheet melting, which results in an average sea-level rise of ~120―140 m. At least three major Melt-Water-Pulse (MWP) events (19ka-MWP, MWP-1A and MWP-1B) are recognizable for the last deglaciation, of which MWP-1A event lasting from ~14.2 to ~13.7 ka B.P. is of the most significance. However, the accurate timing and source of MWP-1A event remain debatable and controversial. It has long been postulated that meltwater of the last deglaciation pouring into the North Atlantic resulted in a slowdown or even a shutdown of the thermohaline circula- tion (THC) which subsequently affected the global climate change. Accordingly, the focus of this debate consists in establishing a reasonable relationship between MWP events and abrupt climate change. Here we summarize a variety of geological and model results for the last deglaciation, reaching a con- clusion that the major MWP events did not correspond with the rigorous stadials, nor always happened within climate reversal intervals. MWP events of the last deglaciation had very weak influences on the intensity of the THC and were not able to trigger a collapse of the global climate. We need to reevaluate the influences of the temporal meltwater variability on the global climate system. deglaciation, Melt-Water-Pulse, thermohaline circulation, abrupt climate change Thermohaline circulation (THC) can be defined as cur- stadial mode, it forms in the subpolar open North Atlan- rents driven by fluxes of heat and freshwater across the tic (that is, south of Iceland), and in Heinrich mode, it sea surface and subsequent interior mixing of heat and almost ceases and water of Antarctic origin fills the deep salt[1].
    [Show full text]
  • Vegetation Responses to Climatic Changes During the Late Glacial According to Palaeobotanical Data in Western Lithuania; a Preliminary Results
    Polish Geological Institute Special Papers, 16 (2005): 45–52 Proceedings of the Workshop “Reconstruction of Quaternary palaeoclimate and palaeoenvironments and their abrupt changes” VEGETATION RESPONSES TO CLIMATIC CHANGES DURING THE LATE GLACIAL ACCORDING TO PALAEOBOTANICAL DATA IN WESTERN LITHUANIA; A PRELIMINARY RESULTS Dalia KISIELIENE1, Migle STANCIKAITE1, Algimantas MERKEVICIUS2, Reda NAMICKIENE2 Abstract. The organic-rich material has been studied from the bottom part of lacustrine sediments of the Lake Kasuciai, west- ern Lithuania. Radiocarbon dates and palaeobotanical data showed that these sediments accumulated between 13,500 and 9000 14C yr BP. The Late Glacial interstadial is defined by the dominance of Characeae and accumulation of carbonate. The Bølling is characterized by the pioneer taxa and the communities of open habitats. During the Allerød pine replaced the light demanding taxa that show development of a closer woodland habitat and dryness of climate. The short period be- tween Bølling and Allerød with increasing representation of Betula and plants typical for the highly eroded habitats could be correlated with Older Dryas. The onset of the Younger Dryas is marked by degradation of the forest cover and expansion of heliophytic grasses. Entire vegetation cover with birch and pine forest was settled during the Preborial. Formation of cal- careous sediments and appearance of thermophilous taxa confirm the climatic amelioration. Key words: environmental changes, pollen and plant macroremains, Late Glacial, western Lithuania. INTRODUCTION In Lithuania the rich data set describing the main features of ecological regime of this area since the 14,000 14C uncalibrated the Younger Dryas and Allerød environment was collected af- BP and until the end of the last termination.
    [Show full text]