471 results match your criteria glacial records

High precise dating on the variation of the Asian summer monsoon since 37 ka BP.

Sci Rep 2021 Apr 30;11(1):9375. Epub 2021 Apr 30.

Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, 55455, USA.

Comprehensive comparison of paleoclimate change based on records constrained by precise chronology and high-resolution is essential to explore the correlation and interaction within earth climate systems. Here, we propose a new stalagmite-based multidecadal resolved Asian summer monsoon (ASM) record spanning the past thirty-seven thousand years (ka BP, before AD 1950) from Furong Cave, southwestern China. This record is consistent with the published Chinese stalagmite sequences and shows that the dominant controls of the ASM dynamics include not only insolation and solar activity but also suborbital-scale hydroclimate events in the high latitudes of the northern hemisphere, such as the Heinrich events, Bølling-Allerød (BA), and Younger Dryas (YD). Read More

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Unravelling the Extent of Diversity within the Iberian Medicinal Leeches (Hirudinea: ) Using Molecules and Morphology.

Biology (Basel) 2021 Apr 9;10(4). Epub 2021 Apr 9.

Department of Zoology and Animal Ecology, V. N. Karazin Kharkiv National University, Maidan Svobody 4, 61022 Kharkiv, Ukraine.

Until the beginning of the 21st century, the famous medicinal leech was thought to be represented by only one species, . However, recent publications have demonstrated that under that name, at least five different species of medicinal leeches were hidden. During the last decade, the biogeography of Western-Palaearctic leeches has begun to unravel, untangling their diversity in practically all of Europe, except for its westernmost peninsula, Iberia. Read More

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Millennial scale feedbacks determine the shape and rapidity of glacial termination.

Nat Commun 2021 04 15;12(1):2273. Epub 2021 Apr 15.

Alfred Wegener Institute, Bremerhaven, Germany.

Within the Late Pleistocene, terminations describe the major transitions marking the end of glacial cycles. While it is established that abrupt shifts in the ocean/atmosphere system are a ubiquitous component of deglaciation, significant uncertainties remain concerning their specific role and the likelihood that terminations may be interrupted by large-amplitude abrupt oscillations. In this perspective we address these uncertainties in the light of recent developments in the understanding of glacial terminations as the ultimate interaction between millennial and orbital timescale variability. Read More

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The anatomy of past abrupt warmings recorded in Greenland ice.

Nat Commun 2021 04 8;12(1):2106. Epub 2021 Apr 8.

Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, USA.

Data availability and temporal resolution make it challenging to unravel the anatomy (duration and temporal phasing) of the Last Glacial abrupt climate changes. Here, we address these limitations by investigating the anatomy of abrupt changes using sub-decadal-scale records from Greenland ice cores. We highlight the absence of a systematic pattern in the anatomy of abrupt changes as recorded in different ice parameters. Read More

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Common Era sea-level budgets along the U.S. Atlantic coast.

Nat Commun 2021 03 23;12(1):1841. Epub 2021 Mar 23.

Earth Observatory of Singapore, Nanyang Technological University, Singapore, Singapore.

Sea-level budgets account for the contributions of processes driving sea-level change, but are predominantly focused on global-mean sea level and limited to the 20th and 21st centuries. Here we estimate site-specific sea-level budgets along the U.S. Read More

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Late glacial (17,060-13,400 cal yr BP) sedimentary and paleoenvironmental evolution of the Sekhokong Range (Drakensberg), southern Africa.

PLoS One 2021 17;16(3):e0246821. Epub 2021 Mar 17.

Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden.

Southern Africa sits at the junction of tropical and temperate systems, leading to the formation of seasonal precipitation zones. Understanding late Quaternary paleoclimatic change in this vulnerable region is hampered by a lack of available, reliably-dated records. Here we present a sequence from a well-stratified sedimentary infill occupying a lower slope basin which covers 17,060 to 13,400 cal yr BP with the aim to reconstruct paleoclimatic variability in the high Drakensberg during the Late Glacial. Read More

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A new global ice sheet reconstruction for the past 80 000 years.

Nat Commun 2021 02 23;12(1):1199. Epub 2021 Feb 23.

Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany.

The evolution of past global ice sheets is highly uncertain. One example is the missing ice problem during the Last Glacial Maximum (LGM, 26 000-19 000 years before present) - an apparent 8-28 m discrepancy between far-field sea level indicators and modelled sea level from ice sheet reconstructions. In the absence of ice sheet reconstructions, researchers often use marine δO proxy records to infer ice volume prior to the LGM. Read More

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February 2021

Rapid warming has resulted in more wildfires in northeastern Australia.

Sci Total Environ 2021 Jun 29;771:144888. Epub 2021 Jan 29.

Archaeology and Natural History, Australian National University, Canberra, Australia.

Wildfires, or bushfires, are one of the most destructive natural disasters in Australia, which can cause many deaths of stock, native animals, sometimes humans, and huge impacts on infrastructure. Reconstructing past wildfires and exploring the links between wildfires and climate are essential for understanding the dynamics of wildfires and for predicting future risks. In this study, the frequency of wildfires in northeastern Australia over the past 25,000 years was reconstructed from the charcoal records preserved in peat and lake sediments. Read More

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Glacial episodes of a freshwater Arctic Ocean covered by a thick ice shelf.

Nature 2021 02 3;590(7844):97-102. Epub 2021 Feb 3.

Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany.

Following early hypotheses about the possible existence of Arctic ice shelves in the past, the observation of specific erosional features as deep as 1,000 metres below the current sea level confirmed the presence of a thick layer of ice on the Lomonosov Ridge in the central Arctic Ocean and elsewhere. Recent modelling studies have addressed how an ice shelf may have built up in glacial periods, covering most of the Arctic Ocean. So far, however, there is no irrefutable marine-sediment characterization of such an extensive ice shelf in the Arctic, raising doubt about the impact of glacial conditions on the Arctic Ocean. Read More

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February 2021

Surface boulder banding indicates Martian debris-covered glaciers formed over multiple glaciations.

Proc Natl Acad Sci U S A 2021 Jan;118(4)

Department of Geology, Colgate University, Hamilton, NY 13346.

Glacial landforms, including lobate debris aprons, are a global water ice reservoir on Mars preserving ice from past periods when high orbital obliquity permitted nonpolar ice accumulation. Numerous studies have noted morphological similarities between lobate debris aprons and terrestrial debris-covered glaciers, an interpretation supported by radar observations. On Earth and Mars, these landforms consist of a core of flowing ice covered by a rocky lag. Read More

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January 2021

Poleward and weakened westerlies during Pliocene warmth.

Nature 2021 01 6;589(7840):70-75. Epub 2021 Jan 6.

Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, USA.

The prevailing mid-latitude westerly winds, known as the westerlies, are a fundamental component of the climate system because they have a crucial role in driving surface ocean circulation and modulating air-sea heat, momentum and carbon exchange. Recent work suggests that westerly wind belts are migrating polewards in response to anthropogenic forcing. Reconstructing the westerlies during past warm periods such as the Pliocene epoch, in which atmospheric carbon dioxide (CO) was about 350 to 450 parts per million and temperatures were about 2 to 4 degrees Celsius higher than today, can improve our understanding of changes in the position and strength of these wind systems as the climate continues to warm. Read More

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January 2021

Testing Seven Hypotheses to Determine What Explains the Current Planthopper (Fulgoridae) Geographical and Species Richness Patterns in China.

Insects 2020 Dec 17;11(12). Epub 2020 Dec 17.

Institute of Entomology, Guizhou University, Guiyang 550025, China.

Although many hypotheses have been proposed to understand the mechanisms underlying large-scale richness patterns, the environmental determinants are still poorly understood, particularly in insects. Here, we tested the relative contributions of seven hypotheses previously proposed to explain planthopper richness patterns in China. The richness patterns were visualized at a 1° × 1° grid size, using 14,722 distribution records for 1335 planthoppers. Read More

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December 2020

The elemental enrichments at Dajiuhu Peatland in the Middle Yangtze Valley in response to changes in East Asian monsoon and human activity since 20,000 cal yr BP.

Sci Total Environ 2021 Feb 30;757:143990. Epub 2020 Nov 30.

School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.

Here we present multiproxy inorganic geochemical records from a peat core (ZK5) from the Dajiuhu Basin in central China to investigate peatland deposition processes and atmospheric metal pollution and to explore their relationships with East Asian monsoon change and human activities in the Middle Yangtze Valley since 20,000 cal yr BP. The peat physicochemical data including total organic carbon (TOC), trace elements, and grain-size show that the site has changed from a lake during the cold-wet Last Glacial Maximum (LGM; 20,000-18,000 cal yr BP), to a marshy wetland during the mild last deglaciation (18,000-11,500 cal yr BP) and a peatland during the mostly warm and dry Holocene (11,500 cal yr BP-present). This general sequence corresponds with changes in East Asian monsoon indicated by stalagmites δO records and boreal summer insolation. Read More

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February 2021

Late Quaternary range shifts of marcescent oaks unveil the dynamics of a major biogeographic transition in southern Europe.

Sci Rep 2020 12 9;10(1):21598. Epub 2020 Dec 9.

CIBIO (Research Center in Biodiversity and Genetic Resources) - InBIO (Research Network in Biodiversity and Evolutionary Biology), University of Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4485-661, Vairão, Portugal.

Marcescent forests are ecotones distributed across southern Europe that host increased levels of biodiversity but their persistence is threatened by global change. Here we study the range dynamics of these forests in the Iberian Peninsula (IP) during the Late Quaternary, a period of profound climate and anthropic changes. We modeled and compared the distribution of eight oak taxa for the present and two paleoclimatic environments, the Last Glacial Maximum (LGM, ~ 21 kya) and the Mid-Holocene (MH, ~ 6 kya). Read More

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December 2020

Late Glacial and Early Holocene human demographic responses to climatic and environmental change in Atlantic Iberia.

Philos Trans R Soc Lond B Biol Sci 2021 01 30;376(1816):20190724. Epub 2020 Nov 30.

I.U. de Investigación en Arqueología y Patrimonio Histórico (INAPH), University of Alicante, Carr. de San Vicente del Raspeig, s/n, 03690 San Vicente del Raspeig, Alicante, Spain.

Successive generations of hunter-gatherers of the Late Glacial and Early Holocene in Iberia had to contend with rapidly changing environments and climatic conditions. This constrained their economic resources and capacity for demographic growth. The Atlantic façade of Iberia was occupied throughout these times and witnessed very significant environmental transformations. Read More

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January 2021

Variations of sedimentary Fe and Mn fractions under changing lake mixing regimes, oxygenation and land surface processes during Late-glacial and Holocene times.

Sci Total Environ 2021 Feb 31;755(Pt 2):143418. Epub 2020 Oct 31.

Institute of Geography & Oeschger Centre for Climate Change Research, University of Bern, Hallerstrasse 12, 3012 Bern, Switzerland. Electronic address:

Global spread of anoxia in aquatic ecosystems has become a major issue that may potentially worsen due to global warming. The reconstruction of long-term hypolimnetic anoxia records can be challenging due to lack of valid and easily measurable proxies. The sedimentary Mn/Fe ratio measured by X-ray fluorescence (XRF) is often used as a proxy for past lake redox conditions. Read More

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February 2021

Alpine glacier resilience and Neoglacial fluctuations linked to Holocene snowfall trends in the western United States.

Sci Adv 2020 Nov 18;6(47). Epub 2020 Nov 18.

Department of Geology, Occidental College, Los Angeles, CA 90041, USA.

Geological evidence indicates that glaciers in the western United States fluctuated in response to Holocene changes in temperature and precipitation. However, because moraine chronologies are characteristically discontinuous, Holocene glacier fluctuations and their climatic drivers remain ambiguous, and future glacier changes are uncertain. Here, we construct a continuous 10-thousand-year (ka) record of glacier activity in the Teton Range, Wyoming, using glacial and environmental indicators in alpine lake sediments. Read More

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November 2020

Past, present and future distributions of Oriental beech (Fagus orientalis) under climate change projections.

PLoS One 2020 17;15(11):e0242280. Epub 2020 Nov 17.

Eurasia Institute of Earth Sciences, Istanbul Technical University, Istanbul, Turkey.

Species distribution models can help predicting range shifts under climate change. The aim of this study is to investigate the late Quaternary distribution of Oriental beech (Fagus orientalis) and to project future distribution ranges under different climate change scenarios using a combined palaeobotanical, phylogeographic, and modelling approach. Five species distribution modelling algorithms under the R-package `biomod2`were applied to occurrence data of Fagus orientalis to predict distributions under present, past (Last Glacial Maximum, 21 ka, Mid-Holocene, 6 ka), and future climatic conditions with different scenarios obtained from MIROC-ESM and CCSM4 global climate models. Read More

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December 2020

A late Pleistocene dataset of Agulhas Current variability.

Sci Data 2020 11 11;7(1):385. Epub 2020 Nov 11.

School of Earth and Environmental Sciences, Cardiff University, Cardiff, CF10 3AT, United Kingdom.

The interocean transfer of thermocline water between the Indian and the Atlantic Oceans known as 'Agulhas leakage' is of global significance as it influences the Atlantic Meridional Overturning Circulation (AMOC) on different time scales. Variability in the Agulhas Current regime is key in shaping hydroclimate on the adjacent coastal areas of the African continent today as well as during past climates. However, the lack of long, continuous records from the proximal Agulhas Current region dating beyond the last glacial cycle prevents elucidation of its role in regional and wider global climate changes. Read More

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November 2020

Rapid reductions and millennial-scale variability in Nordic Seas sea ice cover during abrupt glacial climate changes.

Proc Natl Acad Sci U S A 2020 11 9;117(47):29478-29486. Epub 2020 Nov 9.

Department of Earth Science, University of Bergen, 5007 Bergen, Norway.

Constraining the past sea ice variability in the Nordic Seas is critical for a comprehensive understanding of the abrupt Dansgaard-Oeschger (D-O) climate changes during the last glacial. Here we present unprecedentedly detailed sea ice proxy evidence from two Norwegian Sea sediment cores and an East Greenland ice core to resolve and constrain sea ice variations during four D-O events between 32 and 41 ka. Our independent sea ice records consistently reveal a millennial-scale variability and threshold response between an extensive seasonal sea ice cover in the Nordic Seas during cold stadials and reduced seasonal sea ice conditions during warmer interstadials. Read More

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November 2020

Lagged atmospheric circulation response in the Black Sea region to Greenland Interstadial 10.

Proc Natl Acad Sci U S A 2020 11 2;117(46):28649-28654. Epub 2020 Nov 2.

Marine Geology, Leibniz Institute for Baltic Sea Research Warnemünde, 18119 Rostock, Germany.

Northern Hemispheric high-latitude climate variations during the last glacial are expected to propagate globally in a complex way. Investigating the evolution of these variations requires a precise synchronization of the considered environmental archives. Aligning the globally common production rate variations of the cosmogenic radionuclide Be in different archives provides a tool for such synchronizations. Read More

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November 2020

Long-term cloud forest response to climate warming revealed by insect speciation history.

Evolution 2021 Feb 1;75(2):231-244. Epub 2020 Nov 1.

Island Ecology and Evolution Research Group, Institute of Natural Products and Agrobiology (IPNA-CSIC), La Laguna, 38206, Spain.

Montane cloud forests are areas of high endemism, and are one of the more vulnerable terrestrial ecosystems to climate change. Thus, understanding how they both contribute to the generation of biodiversity, and will respond to ongoing climate change, are important and related challenges. The widely accepted model for montane cloud forest dynamics involves upslope forcing of their range limits with global climate warming. Read More

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February 2021

Andean drought and glacial retreat tied to Greenland warming during the last glacial period.

Nat Commun 2020 10 12;11(1):5135. Epub 2020 Oct 12.

College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, OR, USA.

Abrupt warming events recorded in Greenland ice cores known as Dansgaard-Oeschger (DO) interstadials are linked to changes in tropical circulation during the last glacial cycle. Corresponding variations in South American summer monsoon (SASM) strength are documented, most commonly, in isotopic records from speleothems, but less is known about how these changes affected precipitation and Andean glacier mass balance. Here we present a sediment record spanning the last ~50 ka from Lake Junín (Peru) in the tropical Andes that has sufficient chronologic precision to document abrupt climatic events on a centennial-millennial time scale. Read More

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October 2020

The submerged footprint of Perito Moreno glacier.

Sci Rep 2020 Oct 2;10(1):16437. Epub 2020 Oct 2.

Instituto de Geociencias Básicas, Aplicadas y Ambientales (IGeBA), Ciudad Universitaria, Pabellón II - C1428EHA, CONICET - Universidad de Buenos Aires, Buenos Aires, Argentina.

Perito Moreno is the most famous calving glacier of the South Patagonia Icefield, the largest temperate glacier system of the Southern Hemisphere. Unlike most of the glaciers in the region that have strongly retreated in recent decades, the position of Perito Moreno glacier front remained relatively unchanged in the last century. However, earliest photographic documents show that, at the end of the nineteenth century, the front was ca. Read More

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October 2020

Millennial climate oscillations controlled the structure and evolution of Termination II.

Sci Rep 2020 09 10;10(1):14912. Epub 2020 Sep 10.

School of Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.

The controls that affect the structure and timing of terminations are still poorly understood. We studied a tufa deposit from the Iberian Peninsula that covers Termination II (T-II) and whose chronology was synchronized to speleothem records. We used the same chronology to synchronize ocean sediments from the North Atlantic to correlate major climate events in a common timescale. Read More

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September 2020

Timing and structure of the Younger Dryas event and its underlying climate dynamics.

Proc Natl Acad Sci U S A 2020 09 8;117(38):23408-23417. Epub 2020 Sep 8.

Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN 55455.

The Younger Dryas (YD), arguably the most widely studied millennial-scale extreme climate event, was characterized by diverse hydroclimate shifts globally and severe cooling at high northern latitudes that abruptly punctuated the warming trend from the last glacial to the present interglacial. To date, a precise understanding of its trigger, propagation, and termination remains elusive. Here, we present speleothem oxygen-isotope data that, in concert with other proxy records, allow us to quantify the timing of the YD onset and termination at an unprecedented subcentennial temporal precision across the North Atlantic, Asian Monsoon-Westerlies, and South American Monsoon regions. Read More

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September 2020

Welcome to the Czech Republic again! Rare northern mosses and (Amblystegiaceae) in South Bohemia in light of their European distribution and habitat preferences.

PhytoKeys 2020 4;154:111-136. Epub 2020 Aug 4.

University of Ostrava, Department of Biology and Ecology, 710 00 Ostrava, Czech Republic University of Ostrava Ostrava Czech Republic.

Two aquatic moss species, and (Amblystegiaceae, Bryophyta), which had been considered extinct in the Czech Republic, were found in the Třeboň Basin, South Bohemia, in 2016-2017. They co-occurred in extensive reed- and sedge-dominated fen pools with humic water on the shore of an old fishpond and the former species was also discovered in a small humic pool in an old shallow sand-pit. The new Czech sites of these rare boreal species represent one of the southernmost known outposts within their entire European range. Read More

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Synchronous timing of abrupt climate changes during the last glacial period.

Science 2020 08;369(6506):963-969

Department of Earth Sciences, University of Cambridge, Cambridge, UK.

Abrupt climate changes during the last glacial period have been detected in a global array of palaeoclimate records, but our understanding of their absolute timing and regional synchrony is incomplete. Our compilation of 63 published, independently dated speleothem records shows that abrupt warmings in Greenland were associated with synchronous climate changes across the Asian Monsoon, South American Monsoon, and European-Mediterranean regions that occurred within decades. Together with the demonstration of bipolar synchrony in atmospheric response, this provides independent evidence of synchronous high-latitude-to-tropical coupling of climate changes during these abrupt warmings. Read More

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Impact of 10-Myr scale monsoon dynamics on Mesozoic climate and ecosystems.

Sci Rep 2020 07 23;10(1):11984. Epub 2020 Jul 23.

Department of Geosciences, Graduate School of Science, Shizuoka University, Shizuoka, 790-8577, Japan.

Earth's orbital variations on timescales of 10-10 years, known as Milankovitch cycles, have played a critical role in pacing climate change and ecosystem dynamics, through glacial and/or monsoon dynamics. However, the climatic and biotic consequences of these cycles on much longer (~ 10 years) timescales remain unclear, due to a lack of long proxy records with precise age constraints. Here, we show ~ 10-Myr scale variations in early Mesozoic (250-180 Ma) records of lake-level, desert distribution, biogenic-silica burial flux, atmospheric CO levels (pCO), and sea-surface-temperature (SST). Read More

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The Oldest Highlands of Mars May Be Massive Dust Fallout Deposits.

Sci Rep 2020 06 25;10(1):10347. Epub 2020 Jun 25.

University of North Dakota, Department of Space Studies, Grand Forks, ND, 58202, USA.

The oldest terrains of Mars are cratered landscapes, in which extensive valleys and basins are covered by ubiquitous fluvial plains. One current paradigm maintains that an impact-generated megaregolith underlies these sediments. This megaregolith was likely largely generated during the Early Noachian (~4. Read More

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