Late Quaternary environment of southern Windmill Islands, East Antarctica

2002 ◽  
Vol 14 (4) ◽  
pp. 385-394 ◽  
Author(s):  
HELEN KIRKUP ◽  
MARTIN MELLES ◽  
DAMIAN B. GORE
Keyword(s):  
Late Quaternary ◽  
Ice Core ◽  
Open Water ◽  
Climatic Conditions ◽  
East Antarctica ◽  
The Holocene ◽  
Last Glacial ◽  
The Core ◽  
Windmill Islands ◽  
The Last Glacial

Analyses on a sediment core collected from the Windmill Islands, East Antarctica are used to demonstrate that climatic conditions in this region prior to the Last Glacial Maximum were similar to those during the Holocene and that the area was overrun by ice at some stage between 26 kyr BP and the onset of biogenic sedimentation 11 kyr BP. The 10.9 m long core was taken from a marine inlet (epishelf lake) on Peterson Island and is predominantly a sapropel of Holocene age. Material in the lower part of the core includes a till layer lain down during the last glacial in the region and below this till is material which has been dated to 26 kyr BP. Geochemical analyses conducted on the core demonstrate similarities between the Holocene sequence and the preglacial material. The Holocene sequence shows enhanced biogenic production and periods of open water around 4 kyr BP, suggesting a climatic optimum around that time. A subsequent decline in conditions, probably a colder climate with greater extent of sea ice, is evident from 1 kyr BP to the present. The data support results from ice core studies on nearby Law Dome, which suggest there was a period of warming around 11.5 to 9 kyr BP, that recent summer temperatures are low relative to a few centuries ago, and that increasing winter temperatures are the main contributing factor to a recent overall warming in the region.

scholarly journals Climatic Record From an Ice Margin Area in East Antarctica

1990 ◽  
Vol 14 ◽  
pp. 323-327 ◽  
Author(s):  
T.D. Yao ◽  
J.R. Petit ◽  
J. Jouzel ◽  
C. Lorius ◽  
P. Duval
Keyword(s):  
Ice Core ◽  
East Antarctica ◽  
Deuterium Content ◽  
Ice Crystal ◽  
High Concentration ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Climatic Record ◽  
Ice Crystal Size ◽  
The Last Glacial

Deuterium content, microparticle concentration, ice crystal size and bubble concentration have been studied along an 82 m ice core drilled down to the bedrock in the ice-sheet margin in East Antarctica. The Last Glacial Maximum (LGM) is distinctly marked by low deuterium content, high concentration of microparticles, small ice crystals and high bubble concentrations. This core covers a significant part of the Last Glacial Period with ice from a warmer period recovered around a depth of 60 m.

scholarly journals Exploring the phylogeography and population dynamics of the giant deer ( Megaloceros giganteus ) using Late Quaternary mitogenomes

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
Alba Rey-Iglesia ◽  
Adrian M. Lister ◽  
Paula F. Campos ◽  
Selina Brace ◽  
Valeria Mattiangeli ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Last Glacial Maximum ◽  
Late Pleistocene ◽  
Late Quaternary ◽  
Glacial Maximum ◽  
Climatic Fluctuations ◽  
The Holocene ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Late Quaternary climatic fluctuations in the Northern Hemisphere had drastic effects on large mammal species, leading to the extinction of a substantial number of them. The giant deer ( Megaloceros giganteus ) was one of the species that became extinct in the Holocene, around 7660 calendar years before present. In the Late Pleistocene, the species ranged from western Europe to central Asia. However, during the Holocene, its range contracted to eastern Europe and western Siberia, where the last populations of the species occurred. Here, we generated 35 Late Pleistocene and Holocene giant deer mitogenomes to explore the genetics of the demise of this iconic species. Bayesian phylogenetic analyses of the mitogenomes suggested five main clades for the species: three pre-Last Glacial Maximum clades that did not appear in the post-Last Glacial Maximum genetic pool, and two clades that showed continuity into the Holocene. Our study also identified a decrease in genetic diversity starting in Marine Isotope Stage 3 and accelerating during the Last Glacial Maximum. This reduction in genetic diversity during the Last Glacial Maximum, coupled with a major contraction of fossil occurrences, suggests that climate was a major driver in the dynamics of the giant deer.

The Last Glacial Maximum in northern Baffin Bay

2021 ◽  
Author(s):  
Karen Søby Özdemir ◽  
Henrieka Detlef ◽  
Linda Lambertucci ◽  
Christof Pearce
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Ice Shelf ◽  
Radiocarbon Dates ◽  
The Holocene ◽  
Baffin Bay ◽  
Last Glacial ◽  
The Core ◽  
The Last Glacial Maximum ◽  
The Last Glacial

<p>Little is known about climate and ocean conditions during the Last Glacial Maximum in Baffin Bay, Greenland. This is partly due to the dissolution of biogenic carbonates in the central Baffin Bay, preventing reliable <sup>14</sup>C-chronologies. We present the results from a transect of gravity cores retrieved during the 2019 BIOS cruise on the HDMS Lauge Koch in the northern Baffin Bay. Core LK19-ST8-14G has been analyzed for grain size variations, sea-ice biomarkers, XRF, and color spectrophotometry. A preliminary chronology based on radiocarbon dates from foraminifera show that the bottom of the core is approximately 35.000 cal. years BP while the top sediments are of Late Holocene age. The sediment archive thus covers the full extent of the LGM and the last deglaciation. High-resolution photography and CT scans allowed the identification of distinctly different lithofacies in the sediment archive. The lower sections of the core are characterized by laminated mud with no IRD and absence of microfossils indicating a sub ice-shelf environment during the glacial period. The laminated sequence is interrupted by several coarser, detrital-carbonate (DC) rich layers which are interpreted as episodes of glacial retreat or ice-shelf collapse. The youngest of these DC layers immediately precedes the Holocene, which is represented by approximately 40 cm of bioturbated sediments with some IRD. This interpretation is supported by the concentrations of HBIs and sterols throughout the core, which indicate near perennial ice cover in the glacial northern Baffin Bay and more open water conditions during the Holocene.</p>

Introduction

1998 ◽  
Vol 10 (3) ◽  
pp. 225-226
Author(s):  
Ian D. Goodwin ◽  
Carol J. Pudsey
Keyword(s):  
Regional Differences ◽  
Late Quaternary ◽  
Ice Sheet ◽  
List Type ◽  
Glacial Cycle ◽  
The Holocene ◽  
Last Glacial ◽  
Glacial Stage ◽  
The Antarctic ◽  
The Last Glacial

This issue contains a group of papers selected from those presented at the 1st workshop of the SCAR-GLOCHANT and IGBP-PAGES cosponsored programme on the Late Quaternary Sedimentary Record of the Antarctic Ice Margin Evolution (ANTIME), held in Hobart, 6-1 1 July 1997. ANTIME is focused on the circurn Antarctic reconstruction of palaeoclimate, palaeoenvironment, and ice sheet palaeogeography throughout the last glacial cycle. There were 65 participants from Australia, USA, UK, Italy, Spain, Japan, Sweden, Germany and Russia at the workshop. The participants included representatives of PAGES, IMAGES, and INQUA. The workshop included three scientific sessions on: Extent, timing and regional differences during Glacial Stage 2 (10–30 kyr BP) in Antarctica, from the terrestrial and marine records;Climatic, environmental and glacial events during the Holocene;Late Quaternary geochronological problems in Antarctica.

Stratigraphy, Pollen Analysis, and Paleoclimatic Interpretation of Pulbeena Swamp, Northwestern Tasmania

1982 ◽  
Vol 18 (1) ◽  
pp. 108-126 ◽  
Author(s):  
E. A. Colhoun ◽  
G. van de Geer ◽  
W. G. Mook
Keyword(s):  
Pollen Analysis ◽  
Climatic Conditions ◽  
Major Phase ◽  
The Holocene ◽  
Last Glacial ◽  
Pollen Zone ◽  
Peat Deposits ◽  
Glacial Stage ◽  
The Last Glacial

AbstractSedimentary, palynologic, and 14C analysis of 480 cm of freshwater marl and swamp-peat deposits, formed under the influence of fluctuating artesian springs, provides a paleoenvironmental and paleoclimatic record of approximately 65,000 yr for northwestern Tasmania.The Holocene (Pollen Zone 1, 11,000-0 yr B.P.) climate was warm and moist, and forest vegetation was dominant throughout the area. During the later part of the last glacial stage (Pollen Zone 2, 35,000–11,000 yr B.P.) the climate was generally drier, and grassy open environments were widespread. The driest part of this period occurred between 25,000 to 11,000 yr B.P., when temperatures in western Tasmania were markedly reduced during the last major phase of glaciation. Prior to 35,000 yr B.P. (Pollen Zones 3–9) a long “interstadial complex” dating to the middle of the last glacial stage is recognized. During this period the climate was generally moist, and forest and scrub communities were more important than during the later part of the last glacial stage, except during Pollen Zone 5 when high Gramineae plus Compositae values suggest drier conditions. High Gramineae and Compositae values also occur in Pollen Zone 10 at the base of the diagram. They suggest that a phase of drier and cooler climatic conditions occurred during the early part of the last glacial stage.

scholarly journals Climatic Record From an Ice Margin Area in East Antarctica

1990 ◽  
Vol 14 ◽  
pp. 323-327 ◽  
Author(s):  
T.D. Yao ◽  
J.R. Petit ◽  
J. Jouzel ◽  
C. Lorius ◽  
P. Duval
Keyword(s):  
Ice Core ◽  
East Antarctica ◽  
Deuterium Content ◽  
Ice Crystal ◽  
High Concentration ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Climatic Record ◽  
Ice Crystal Size ◽  
The Last Glacial

Deuterium content, microparticle concentration, ice crystal size and bubble concentration have been studied along an 82 m ice core drilled down to the bedrock in the ice-sheet margin in East Antarctica. The Last Glacial Maximum (LGM) is distinctly marked by low deuterium content, high concentration of microparticles, small ice crystals and high bubble concentrations. This core covers a significant part of the Last Glacial Period with ice from a warmer period recovered around a depth of 60 m.

scholarly journals Volcanic forcing and climate variations during the last glacial period

2012 ◽  
Vol 8 (5) ◽  
pp. 4941-4956
Author(s):  
A. F. Flinders
Keyword(s):  
Late Quaternary ◽  
Ice Core ◽  
Greenland Ice Sheet ◽  
Volcanic Eruptions ◽  
Temporal Variations ◽  
Atmospheric Co2 ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Last Glacial

Abstract. Measurements of δ18O in the Greenland Ice Sheet Project 2 (GISP2) ice-core from Summit, Greenland, show repeated temporal variations associated with rapid warming events throughout the last glacial period of the Pleistocene-10–110 kya. The majority of these warming events are preceded in the ice-core record by an increased concentration of insoluble micro-particulate sulfate, indicative of increases in global volcanism. Wavelet analysis of ice-core and marine-sediment records show a repeated 5000–6000 yr periodicity in both volcanic SO4 and δ18O ice records, as well as a 5000–8000 yr cycle in the lithic concentration of ice-rafted debris, atmospheric CO2 concentration, and a database of late Quaternary volcanic eruptions. Increasing concentrations in atmospheric CO2 and CH4 initiated during periods of increased volcanism, peaking during a warm transition, reflect a volcanic-atmospheric-deglaciation feedback, regulated by meridional overturning current-shutdown related cooling.

Late Quaternary climate-driven environmental change in the Larsemann Hills, East Antarctica, multi-proxy evidence from a lake sediment core

2005 ◽  
Vol 64 (1) ◽  
pp. 83-99 ◽  
Author(s):  
Dominic A. Hodgson ◽  
Elie Verleyen ◽  
Koen Sabbe ◽  
Angela H. Squier ◽  
Brendan J. Keely ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Accumulation Rate ◽  
Late Quaternary ◽  
East Antarctica ◽  
Algal Community ◽  
Data Set ◽  
Last Glacial ◽  
Larsemann Hills ◽  
Quaternary Climate ◽  
The Last Glacial

AbstractLittle is known about the response of terrestrial East Antarctica to climate changes during the last glacial–interglacial cycle. Here we present a continuous sediment record from a lake in the Larsemann Hills, situated on a peninsula believed to have been ice-free for at least 40,000 yr. A mutli-proxy data set including geochronology, diatoms, pigments and carbonate stable isotopes indicates warmer and wetter conditions than present in the early part of the record. We interpret this as Marine Isotope Stage 5e after application of a chronological age-depth model and similar ice core evidence. Dry and cold conditions are inferred during the last glacial, with lake-level minima, floristic changes towards a shallow water algal community, and a greater biological receipt of ultraviolet radiation. During the Last Glacial Maximum and Termination I the lake was perennially ice-covered, with minimal snowmelt in the catchment. After ca. 10,500 cal yr B.P., the lake became seasonally moated or ice-free during summer. Despite a low accumulation rate, the sediments document some Holocene environmental changes including neoglacial cooling after ca. 2450 cal yr B.P., and a gradual increase in aridity and salinity to the present.

A multidisciplinary approach to reveal the Sicily Climate and Environment over the last 20 000 years

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Alessandro Incarbona ◽  
Giuseppe Zarcone ◽  
Mauro Agate ◽  
Sergio Bonomo ◽  
Enrico Stefano ◽  
...  
Keyword(s):  
Vegetation Pattern ◽  
Significant Loss ◽  
Climatic Conditions ◽  
Ice Age ◽  
Geochemical Data ◽  
Climatic Fluctuations ◽  
The Holocene ◽  
Last Glacial ◽  
General Decline ◽  
The Last Glacial

AbstractWe present a thorough review of the knowledge on the climate and environment in Sicily over the last 20 000 years, taking into account results of several studies carried using terrestrial and marine records. We obtain a coherent framework of the most important changes succeeded in the island, even if some points need further investigation.All the reconstructions of surface temperatures of the seas and the air surrounding Sicily point out severe climatic conditions during the last glacial period. The steppe- and semisteppe-like vegetation pattern testifies, together with additional evidence from geochemical data of lacustrine evidence, markedly arid conditions. Fi-nally, significant episodes of sea level drop connected Sicily to the Italian Peninsula and favoured the dispersion of faunal elements from southern Italy.The transition between the last glacial and the Holocene was not characterized by a gradual warming but was punctuated by two abrupt suborbital climatic fluctuations: Bølling-Allerød (warm) and Younger Dryas (cold), as recognized in the sediments recovered close to the northern and southern coast of Sicily. A denser arboreal cover is possibly indicated by the occurrence of dormouse and Arvicola remains.Finally the sensitivity of Sicily to climate perturbations is demonstrated by the occurrence of repeated subtle climatic anomalies during the Holocene, including the Little Ice Age, also known from historical chronicles. Forests, woods and Mediterranean maquis developed in the early-middle Holocene. Thereafter was a general decline of arboreal vegetation, following a general aridification trend that seems to be a common feature in southern Europe and North Africa. Science Greek colonization (7th century before Christ), the landscape was intensively modelled for agriculture and breeding, leading to a significant loss of vegetation cover.

scholarly journals Paleoproductivity changes during the Late Quaternary in the southeastern Brazilian upper continental margin of the Southwestern Atlantic

2010 ◽  
Vol 58 (spe1) ◽  
pp. 31-41 ◽  
Author(s):  
Renata Hanae Nagai ◽  
Silvia Helena de Mello e Sousa ◽  
Rafael André Lourenço ◽  
Márcia Caruso Bícego ◽  
Michel Michaelovitch de Mahiques
Keyword(s):  
Sea Level ◽  
Continental Margin ◽  
Late Quaternary ◽  
Climatic Conditions ◽  
Continental Margins ◽  
The Holocene ◽  
Sea Level Fluctuations ◽  
Brazil Current ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Changes in the Brazilian continental margins oceanic productivity and circulation over the last 27,000 years were reconstructed based on sedimentological and microfaunal analyses. Our results suggest that oceanic paleoproductivity and the supply of terrigenous sediments to the Brazilian continental margin were higher during the Last Glacial Maximum (LGM) than during the Holocene. These changes may have been primarily influenced by significant sea level fluctuations that have occurred since the late Pleistocene. During the LGM, the lower sea level, higher productivity and lower sea-surface paleotemperatures may have been the result of the offshore displacement of the main flow of the Brazil Current. However, during the Holocene, the warm waters of the Brazil Current were displaced toward the coast. This displacement contributed to the increase in water temperature and prevented an increase in oceanic productivity. The decrease in terrigenous supply since the LGM could be related to the increase of the extension of the continental shelf and/or drier climatic conditions.

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