Recurrent outburst floods and explosive volcanism during the Younger Dryas–Early Holocene deglaciation in south Iceland: evidence from a lacustrine record

2021 ◽  
Author(s):  
Áslaug Geirsdóttir ◽  
Gifford H. Miller ◽  
David J. Harning ◽  
Hrafnhildur Hannesdóttir ◽  
Thor Thordarson ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Explosive Volcanism ◽  
Early Holocene ◽  
Outburst Floods

scholarly journals Millennial‐scale deglaciation across the European Alps at the transition between the Younger Dryas and the Early Holocene – evidence from a new cosmogenic nuclide chronology

Boreas ◽  
2021 ◽  
Author(s):  
Marie Protin ◽  
Irene Schimmelpfennig ◽  
Jean‐Louis Mugnier ◽  
Jean‐François Buoncristiani ◽  
Melaine Le Roy ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Early Holocene ◽  
European Alps ◽  
Cosmogenic Nuclide ◽  
Millennial Scale

scholarly journals How dry was the Younger Dryas? Evidence from a coupled <i>δ</i><sup>2</sup>H–<i>δ</i><sup>18</sup>O biomarker paleohygrometer applied to the Gemündener Maar sediments, Western Eifel, Germany

2019 ◽  
Vol 15 (2) ◽  
pp. 713-733 ◽  
Author(s):  
Johannes Hepp ◽  
Lorenz Wüthrich ◽  
Tobias Bromm ◽  
Marcel Bliedtner ◽  
Imke Kathrin Schäfer ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Younger Dryas ◽  
Late Glacial ◽  
Climatic Conditions ◽  
Leaf Water ◽  
Early Holocene ◽  
Unexpected Finding ◽  
Temperature Dependent ◽  
The Past ◽  
Natural Climate

Abstract. Causes of the Late Glacial to Early Holocene transition phase and particularly the Younger Dryas period, i.e. the major last cold spell in central Europe during the Late Glacial, are considered to be keys for understanding rapid natural climate change in the past. The sediments from maar lakes in the Eifel, Germany, have turned out to be valuable archives for recording such paleoenvironmental changes. For this study, we investigated a Late Glacial to Early Holocene sediment core that was retrieved from the Gemündener Maar in the Western Eifel, Germany. We analysed the hydrogen (δ2H) and oxygen (δ18O) stable isotope composition of leaf-wax-derived lipid biomarkers (n-alkanes C27 and C29) and a hemicellulose-derived sugar biomarker (arabinose), respectively. Both δ2Hn-alkane and δ18Osugar are suggested to reflect mainly leaf water of vegetation growing in the catchment of the Gemündener Maar. Leaf water reflects δ2H and δ18O of precipitation (primarily temperature-dependent) modified by evapotranspirative enrichment of leaf water due to transpiration. Based on the notion that the evapotranspirative enrichment depends primarily on relative humidity (RH), we apply a previously introduced “coupled δ2Hn-alkane–δ18Osugar paleohygrometer approach” to reconstruct the deuterium excess of leaf water and in turn Late Glacial–Early Holocene RH changes from our Gemündener Maar record. Our results do not provide evidence for overall markedly dry climatic conditions having prevailed during the Younger Dryas. Rather, a two-phasing of the Younger Dryas is supported, with moderate wet conditions at the Allerød level during the first half and drier conditions during the second half of the Younger Dryas. Moreover, our results suggest that the amplitude of RH changes during the Early Holocene was more pronounced than during the Younger Dryas. This included the occurrence of a “Preboreal Humid Phase”. One possible explanation for this unexpected finding could be that solar activity is a hitherto underestimated driver of central European RH changes in the past.

scholarly journals Revisions and Extension of the Hohenheim Oak and Pine Chronologies: New Evidence About the Timing of the Younger Dryas/Preboreal Transition

Radiocarbon ◽  
1998 ◽  
Vol 40 (3) ◽  
pp. 1107-1116 ◽  
Author(s):  
Marco Spurk ◽  
Michael Friedrich ◽  
Jutta Hofmann ◽  
Sabine Remmele ◽  
Burkhard Frenzel ◽  
...  
Keyword(s):  
Calibration Curve ◽  
Younger Dryas ◽  
Ice Cores ◽  
Early Holocene ◽  
Proxy Data ◽  
The Past ◽  
Varve Chronology ◽  
New Evidence ◽  
Radiocarbon Calibration

Oak and pine samples housed at the Institute of Botany, University of Hohenheim, are the backbone of the early Holocene part of the radiocarbon calibration curve, published in 1993 (Becker 1993; Kromer and Becker 1993; Stuiver and Becker 1993; Vogel et al. 1993). Since then the chronologies have been revised. The revisions include 1) the discovery of 41 missing years in the oak chronology and 2) a shift of 54 yr for the oldest part back into the past. The oak chronology was also extended with new samples as far back as 10,429 BP (8480 BC). In addition, the formerly tentatively dated pine chronology (Becker 1993) has been rebuilt and shifted to an earlier date. It is now positioned by 14C matching at 11,871-9900 BP (9922–7951 BC) with an uncertainty of ±20 yr (Kromer and Spurk 1998). With these new chronologies the 14C calibration curve can now be corrected, eliminating the discrepancy in the dating of the Younger Dryas/Preboreal transition between the proxy data of the GRIP and GISP ice cores (Johnsen et al. 1992; Taylor et al. 1993), the varve chronology of Lake Gościąż (Goslar et al. 1995) and the pine chronology (Becker, Kromer and Trimborn 1991).

scholarly journals A major hydrobiological change in Dasht-e Arjan Wetland (southwestern Iran) during the late glacial – early Holocene transition revealed by subfossil chironomids

2019 ◽  
Vol 56 (8) ◽  
pp. 848-856
Author(s):  
Cyril Aubert ◽  
Morteza Djamali ◽  
Matthew Jones ◽  
Hamid Lahijani ◽  
Nick Marriner ◽  
...  
Keyword(s):  
Lake Level ◽  
Regional Scale ◽  
Younger Dryas ◽  
Late Glacial ◽  
Early Holocene ◽  
Geochemical Data ◽  
The Holocene ◽  
Chironomus Plumosus ◽  
Subfossil Chironomids ◽  
Southwestern Iran

The late glacial – early Holocene transition is a key period in the earth’s history. However, although this transition is well studied in Europe, it is not well constrained in the Middle East and palaeohydrological records with robust chronologies remain scarce from this region. Here we present an interesting hydrobiological record showing a major environmental change occurring in the Dasht-e Arjan Wetland (southwestern Iran, near to Persepolis) during the late glacial – early Holocene transition (ca. 11 650 years cal BP). We use subfossil chironomids (Insecta: Diptera) as a proxy for hydrological changes and to reconstruct lake-level fluctuations. The Arjan wetland was a deep lake during the Younger Dryas marked by a dominance of Chironomus plumosus/anthracinus-type, taxa adapted to anoxic conditions of deep waters. At the beginning of the Holocene, a drastic decrease (more than 80% to less than 10%) of Chironomus plumosus/anthracinus-type, combined with diversification of littoral taxa such as Polypedilum nubeculosum-type, Dicrotendipes nervosus-type, and Glyptotendipes pallens-type, suggests a lake-level decrease and a more vegetalized aquatic environment. We compare and contrast the chironomid record of Arjan with a similar record from northwestern Iran. The palaeoclimatic significance of the record, at a local and regional scale, is subsequently discussed. The increase in Northern Hemisphere temperatures, inferred by geochemical data from NGRIP, at the beginning of the Holocene best explains the change from the Younger Dryas highstand to early Holocene lowstand conditions in the Dasht-e Arjan wetland. However, a contribution of the meltwater inflow from small local glaciers in the catchment basin is not excluded.

scholarly journals River of Change: a Model for the Development of Terraces Along the Bow River, Alberta

2004 ◽  
Vol 56 (2-3) ◽  
pp. 155-169 ◽  
Author(s):  
Gerald A. Oetelaar
Keyword(s):  
Late Pleistocene ◽  
Rocky Mountains ◽  
Sediment Load ◽  
Younger Dryas ◽  
Early Holocene ◽  
Stream Power ◽  
Independent Variables ◽  
The Past ◽  
Initial Episode ◽  
Alluvial Terraces

Abstract Researchers working in the Bow River valley have identified a minimum of four alluvial terraces, the upper two of which have been designated as paired terraces. Over the past 35 years, they have attempted to correlate these alluvial landforms and to generate models for the development of the terraces along the section of the Bow River between Calgary and the Rocky Mountains. In this study, Mazama ash and an early Holocene paleosol are used to correlate the terrace suites examined by previous researchers and to generate a model which accounts for the development of the upper two sets of paired terraces. These paired terraces reflect major episodes of aggradation and degradation that result from changes in independent variables such as climate and uplift. The initial episode of aggradation, dating from the late Pleistocene, is the result of paraglacial processes in a sparsely vegetated, yet saturated environment. Following a brief episode of degradation at the end of the Younger Dryas, the second episode of aggradation, dating from 9000 to 5000 BP, is caused by increased sediment load and lowered stream power during the Hypsithermal.

Reconstruction of Early Holocene jokulhlaups along the Hvita River and Gullfoss waterfall, Iceland

2020 ◽  
Author(s):  
Greta Wells ◽  
Þorsteinn Sæmundsson ◽  
Sheryl Luzzadder-Beach ◽  
Timothy Beach ◽  
Andrew Dugmore
Keyword(s):  
Ice Sheet ◽  
Hydraulic Modeling ◽  
Early Holocene ◽  
Glacial Lake ◽  
Exposure Dating ◽  
Alpine Regions ◽  
Outburst Floods ◽  
Lake Formation ◽  
Geothermal Activity ◽  
Downstream Communities

&lt;p&gt;Glacial lake outburst floods (GLOFs) have occurred across the planet throughout the Quaternary and are a significant geohazard in Arctic and alpine regions today. Iceland experiences more frequent GLOFs&amp;#8212;known in Icelandic as j&amp;#246;kulhlaups&amp;#8212;than nearly anywhere on Earth, yet most research focuses on floods triggered by subglacial volcanic and geothermal activity. However, floods from proglacial lakes may be a better analogue to most global GLOFs.&lt;/p&gt;&lt;p&gt;As the Icelandic Ice Sheet retreated across Iceland in the Late Pleistocene-Early Holocene, meltwater pooled at ice margins and periodically drained in j&amp;#246;kulhlaups. Some of the most catastrophic floods drained from ice-dammed Glacial Lake Kj&amp;#246;lur, surging across southwestern Iceland from the interior highlands to the Atlantic Ocean. These floods left extensive geomorphologic evidence along the modern-day course of the Hv&amp;#237;t&amp;#225; River, including canyons, scoured bedrock, boulder deposits, and Gullfoss&amp;#8212;Iceland&amp;#8217;s most famous waterfall. The largest events reached an estimated maximum peak discharge of 300,000 m&lt;sup&gt;3&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;, ranking them among the largest known floods in Iceland and on Earth.&lt;/p&gt;&lt;p&gt;Yet, all our evidence for the Kj&amp;#246;lur j&amp;#246;kulhlaups comes from only one publication to date (T&amp;#243;masson, 1993). My research employs new methods to better constrain flood timing, routing, magnitude, and recurrence interval at this underexplored site. This talk presents new and synthesized j&amp;#246;kulhlaup geomorphologic evidence; HEC-RAS hydraulic modeling results of flow magnitude and routing; and ongoing geochronological analyses using cosmogenic nuclide exposure dating and tephrochronology. It also situates these events within Icelandic Ice Sheet deglaciation chronology and environmental change at the Pleistocene-Holocene transition. Finally, it examines the Kj&amp;#246;lur floods as an analogue to contemporary ice sheet response, proglacial lake formation, and j&amp;#246;kulhlaup processes and landscape evolution in Arctic and alpine regions worldwide, where GLOFs pose an increasing risk to downstream communities due to climate-driven meltwater lake expansion. &amp;#160;&lt;/p&gt;&lt;p&gt;Citation: T&amp;#243;masson, H., 1993. J&amp;#246;kulst&amp;#237;flu&amp;#240; v&amp;#246;tn &amp;#225; Kili og hamfarahlaup &amp;#237; Hv&amp;#237;t&amp;#225; &amp;#237; &amp;#193;rness&amp;#253;slu. N&amp;#225;tt&amp;#250;rufr&amp;#230;&amp;#240;ingurinn 62, 77-98.&lt;/p&gt;

A multiproxy study of Younger Dryas and Early Holocene climatic conditions from the Grabia River paleo-oxbow lake (central Poland)

2015 ◽  
Vol 438 ◽  
pp. 34-50 ◽  
Author(s):  
Dominik Pawłowski ◽  
Mateusz Płóciennik ◽  
Stephen J. Brooks ◽  
Tomi P. Luoto ◽  
Krystyna Milecka ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Climatic Conditions ◽  
Early Holocene ◽  
Oxbow Lake ◽  
Central Poland

scholarly journals Palynology and Archaeology of Late Vistulian and Early Holocene Sites in Lubuskie Lake District, Western Poland

2014 ◽  
Vol 31 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Iwona Okuniewska-Nowaczyk ◽  
Iwona Sobkowiak-Tabaka
Keyword(s):  
Small Area ◽  
Younger Dryas ◽  
Late Glacial ◽  
Early Holocene ◽  
Lake District ◽  
Multidisciplinary Research ◽  
Late Vistulian ◽  
Palynological Spectrum ◽  
History Of ◽  
Palynological Records

Abstract The Lubuskie Lake District played an important part in recolonisation of the Polish Plain due to its location and the character of the terrain. Despite that, it is and especially its northern part, poorly explored regarding both history of Late Glacial and early Holocene settlements, and the natural environment. The paper presents results of multidisciplinary research in this area. The most spectacular discoveries were connected with remains of settlements of the Hamburgian culture societies at Myszęcin - currently the richest site of this culture over the entire North European Plain. In the vicinity of this site several Late Palaeolithic and Mesolithic settlements of varied functions were recorded. First palynological records came from the Younger Dryas sediments in this area. In a log with a palynological spectrum comprising Younger Dryas and the beginning of the Holocene, a charcoal dust was found and it could indicate human activity as humans lived at a lake shore. An important complement to the image of the Late Glacial settlement at the Lubuskie Lake District was provided by the research near Lubrza that resulted in data regarding settlements of the Federmesser and Świderian culture societies. This region was not typical in a palynological spectrum of deposits during Allerød but also indicated highly diversified thickness of basal peat in a small area.

Sign in / Sign up

Export Citation Format

Share Document