scholarly journals Glacial history of Inglefield Land, north Greenland from combined in-situ <sup>10</sup>Be and <sup>14</sup>C exposure dating

2020 ◽  
Author(s):  
Anne Sofie Søndergaard ◽  
Nicolaj Krog Larsen ◽  
Olivia Steinemann ◽  
Jesper Olsen ◽  
Svend Funder ◽  
...  
Keyword(s):  
Climate Changes ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Age ◽  
Glacial History ◽  
Holocene Climate ◽  
Exposure Dating ◽  
History Of ◽  
North Greenland

Abstract. Exposing the sensitivity of the Greenland Ice Sheet (GrIS) to Holocene climate changes is a key prerequisite for understanding the future response of the ice sheet to global warming. In this study, we present new information on the Holocene glacial history of the GrIS in Inglefield Land, north Greenland. We use 10Be and in-situ 14C exposure dating to constrain the timing of deglaciation in the area and radiocarbon dating of reworked molluscs and wood fragments to constrain when the ice sheet retreated behind its present-day extent. The 10Be ages are scattered ranging from c. 92.7 to 6.8 ka whereas the in-situ 14C ages range from c. 14.2 to 6.7 ka. Almost half of the apparent 10Be ages predate the Last Glacial Maximum and up to 89 % are to some degree affected by nuclide inheritance. Based on the few reliable 10Be ages, the in-situ 14C ages and existing radiocarbon ages from Inglefield Land, we find that the deglaciation along the coast commenced c. 8.6–8.3 cal. ka BP in the western part and c. 7.9 ka in the central part, following the opening of Nares Strait and arrival of warm waters. The ice margin reached its present-day position c. 8.2 ka at the Humboldt Glacier and c. 6.7 ka in the central part of Inglefield Land. Radiocarbon ages of reworked molluscs and wood fragments show that the ice margin was behind its present-day extent from c. 5.8 to 0.5 cal. ka BP. After 0.5 cal. ka BP, the ice advanced towards its Little Ice Age position. Our results emphasize that the slowly eroding and possibly cold-based ice in north Greenland makes it difficult to constrain the deglaciation history based on 10Be ages alone unless it is paired with in-situ 14C ages. Further, combining our findings with those of recently published studies reveals distinct differences between deglaciation patterns of northwest and north Greenland. Deglaciation of the land areas in northwest Greenland occurred earlier than in north Greenland and periods of restricted ice extent were longer, spanning middle and late Holocene. Overall, this highlights past ice sheet sensitivity towards Holocene climate changes in an area where little information was available just a few years ago.

scholarly journals Glacial history of Inglefield Land, north Greenland from combined in situ <sup>10</sup>Be and <sup>14</sup>C exposure dating

2020 ◽  
Vol 16 (5) ◽  
pp. 1999-2015
Author(s):  
Anne Sofie Søndergaard ◽  
Nicolaj Krog Larsen ◽  
Olivia Steinemann ◽  
Jesper Olsen ◽  
Svend Funder ◽  
...  
Keyword(s):  
Climate Changes ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Age ◽  
Glacial History ◽  
Holocene Climate ◽  
Exposure Dating ◽  
History Of ◽  
North Greenland

Abstract. Determining the sensitivity of the Greenland Ice Sheet (GrIS) to Holocene climate changes is a key prerequisite for understanding the future response of the ice sheet to global warming. In this study, we present new information on the Holocene glacial history of the GrIS in Inglefield Land, north Greenland. We use 10Be and in situ 14C exposure dating to constrain the timing of deglaciation in the area and radiocarbon dating of reworked molluscs and wood fragments to constrain when the ice sheet retreated behind its present-day extent. The 10Be ages are scattered ranging from ca. 92.7 to 6.8 ka, whereas the in situ 14C ages range from ca. 14.2 to 6.7 ka. Almost half of the apparent 10Be ages predate the Last Glacial Maximum and up to 89 % are to some degree affected by nuclide inheritance. Based on the few reliable 10Be ages, the in situ 14C ages and existing radiocarbon ages from Inglefield Land, we find that the deglaciation along the coast commenced at ca. 8.6–8.3 ka cal BP in the western part and ca. 7.9 ka in the central part, following the opening of Nares Strait and arrival of warm waters. The ice margin reached its present-day position at ca. 8.2 ka at the Humboldt Glacier and ca. 6.7 ka in the central part of Inglefield Land. Radiocarbon ages of reworked molluscs and wood fragments show that the ice margin was behind its present-day extent from ca. 5.8 to 0.5 ka cal BP. After 0.5 ka cal BP, the ice advanced towards its Little Ice Age position. Our results emphasize that the slowly eroding and possibly cold-based ice in north Greenland makes it difficult to constrain the deglaciation history based on 10Be ages alone unless they are paired with in situ 14C ages. Further, combining our findings with those of recently published studies reveals distinct differences between deglaciation patterns of northwest and north Greenland. Deglaciation of the land areas in northwest Greenland occurred earlier than in north Greenland, and periods of restricted ice extent were longer, spanning the Middle and Late Holocene. Overall, this highlights past ice sheet sensitivity to Holocene climate changes in an area where little information was available just a few years ago.

The Glacial History of the Svalberd Archipelago from Late Vistulian to the Present Time / Historia zlodowacenia archipelagu Svalbard od późnego vistulianu do współczesności

2014 ◽  
Vol 69 (2) ◽  
Author(s):  
Joanna Ćwiąkała ◽  
Mateusz Moskalik ◽  
Jan Rodzik ◽  
Piotr Zagórski
Keyword(s):  
Continental Shelf ◽  
20Th Century ◽  
Ice Sheet ◽  
Ice Age ◽  
The Arctic ◽  
Glacial History ◽  
Svalbard Archipelago ◽  
Maximum Extent ◽  
Late Vistulian ◽  
History Of

AbstractThe glacial history of the Svalbard archipelago is often a hot topic for researches, but the articles usually refer to a particular piece of Svalbard. The authors of this work studied many scientific articles based on the researches to find and collect this history. Svalbard archipelago is located in the Arctic, at the edge of the continental shelf of Europe. The end of shelf boundary noted occurrence of ice caps in the past glaciations. In turn, the main elements of the landscape of the archipelago are glaciers that are currently in a recession. Spitsbergen (the biggest island of the archipelago) sets the limit of Pleistocene glaciations, and the current state of glaciers allows determining the place where the recession is intense. The main aim of the authors in this study is to show this history only from the late Vistulian to the late Holocene (the beginning of 21st century). Interstadials and Stadials start time varies, as their duration in different places, according to various authors. It is very hard to collect all information and describe this history. By knowing the history of glaciation, we can distinguish in the late Vistulian: Last Glacial Maximum (LGM), Bølling/Older Dryas/Allerød and Younger Dryas (YD). LGM was the stadial in which was the maximum extent of ice sheet in late Vistulian. After this period, ice sheet began to retreat from the continental shelf. In turn, YD was the stadial in which the last advance of glaciers took place, about 11 000 years BC. In the Holocene we can distinguish Holocene Climatic Optimum (in the meantime short Cooling Holocene), Revdalen Stadial, Medieval Warm Period, Little Ice Age (LIA) and 20th century warming. The maximum extent of glaciers in Holocene was in LIA. In LIA, the extent of glaciers was bigger than in YD. In 20th century a warming started and continues until now.

scholarly journals The timing of fjord formation and early glaciations in North and Northeast Greenland

2020 ◽  
Author(s):  
Vivi Kathrine Pedersen ◽  
Nicolaj Krog Larsen ◽  
David Lundbek Egholm
Keyword(s):  
Late Miocene ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Early History ◽  
Early Pleistocene ◽  
Late Pliocene ◽  
Isostatic Uplift ◽  
History Of ◽  
Erosional Unloading ◽  
North Greenland

&lt;p&gt;The timing and extent of early glaciations in Greenland, and their co-evolution with the underlying landscape remain elusive. In this study, we explore the timing of fjord erosion in Northeast and North Greenland between Scoresby Sund (70&amp;#176;N) and Independence Fjord (82&amp;#176;N). By determining the timing of fjord formation, we can improve our understanding of the early history of the Greenland Ice Sheet in these regions.&lt;/p&gt;&lt;p&gt;We use the concept of geophysical relief to estimate fjord erosion and calculate the subsequent flexural isostatic response to erosional unloading. The timing of erosion and isostatic uplift is constrained by marine sediments of late Pliocene-early Pleistocene age that are now exposed on land between ~24 and 230 m a.s.l.&lt;/p&gt;&lt;p&gt;We find that the northern Independence Fjord system must have formed by glacial erosion at average rates of ~0.5-1 mm/yr since ~2.5 Ma, in order to explain the current elevation of the marine Kap K&amp;#248;benhavn Formation by erosion-induced isostatic uplift. In contrast, fjord formation in the outer parts of southward Scoresby Sund commenced before the Pleistocene, most likely in late Miocene, and continued throughout the Pleistocene by fjord formation progressing inland. Our results suggest that the inception of the Greenland Ice Sheet began in the central parts of Northeast Greenland before the Pleistocene and spread to North Greenland only at the onset of the Pleistocene. &amp;#160;&lt;/p&gt;

scholarly journals Spatial and temporal oxygen isotope variability in northern Greenland – implications for a new climate record over the past millennium

2015 ◽  
Vol 11 (3) ◽  
pp. 2341-2388
Author(s):  
S. Weißbach ◽  
A. Wegner ◽  
T. Opel ◽  
H. Oerter ◽  
B. M. Vinther ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Signal To Noise Ratio ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Ice Age ◽  
Temperature History ◽  
Mean Values ◽  
The North ◽  
North Greenland

Abstract. We present for the first time all 12 δ18O records obtained from ice cores drilled in the framework of the North Greenland Traverse (NGT) between 1993 and 1995 in northern Greenland between 74 to 80° N, 36 to 49° W and 2000 to 3200 m a.s.l. The cores cover an area of 680 km × 317 km, ~200 000 km2 or 10 % of the area of Greenland. Depending on core length (100–175 m) and accumulation rate (90–200 kg m−2 a−1) the records reflect an isotope-temperature history over the last 500–1100 years. The δ18O signal in northern Greenland is influenced by temperature, accumulation and the topography of the North Greenland ice sheet between 72 and 80° N. About 12 % of the variability can be attributed to the position of the single drill sites in relation to the ice sheet topography. Lowest δ18O mean values occur north of summit and east of the main divide. In general, ice cores drilled on the main ice divide show different results than those drilled east of the main ice divide that might be influenced by secondary regional moisture sources. A stack of all 12 NGT records and the NGRIP record is presented with improved signal-to-noise ratio. This stack represents the mean δ18O signal for northern Greenland that is interpreted as proxy for temperature. Our northern Greenland δ18O stack indicates isotopically enriched periods compared to their average during medieval times, about 1420 ± 20 AD and from 1870 AD onwards. The period between 1420 AD and 1850 AD was isotopically depleted compared to the average for the entire millennium and represents the Little Ice Age. The 20th century has isotopic values higher than the 1000 years mean and is comparable to the medieval period but lower than about 1420 AD.

scholarly journals Glacial history of the Greenland Ice Sheet and a local ice cap in Qaanaaq, northwest Greenland

2019 ◽  
Vol 34 (7) ◽  
pp. 536-547 ◽  
Author(s):  
Anne Sofie Søndergaard ◽  
Nicolaj Krog Larsen ◽  
Jesper Olsen ◽  
Astrid Strunk ◽  
Sarah Woodroffe
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Glacial History ◽  
Ice Cap ◽  
History Of

scholarly journals The timing of fjord formation and early glaciations in North and Northeast Greenland

2021 ◽  
Author(s):  
Vivi Kathrine Pedersen ◽  
Nicolaj Krog Larsen ◽  
David Lundbek Egholm
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Early History ◽  
Early Pleistocene ◽  
East Greenland ◽  
Late Pliocene ◽  
Isostatic Uplift ◽  
History Of ◽  
Erosional Unloading ◽  
North Greenland

&lt;p&gt;The timing and extent of early glaciations in Greenland, and their co-evolution with the underlying landscape remain elusive. In this study, we explore the timing of fjord formation in Northeast and North Greenland, between Scoresby Sund (70&amp;#176;N) and Independence Fjord (82&amp;#176;N). By determining the timing of fjord formation, we can improve our understanding of the early history of the Greenland Ice Sheet in these regions. We use the concept of geophysical relief to estimate fjord erosion volumes and calculate the subsequent flexural isostatic response to erosional unloading. The timing of erosion and isostatic uplift is constrained by marine sediments of late Pliocene-early Pleistocene age that are now exposed on land between ~24 and 230 m a.s.l. The late Pliocene-early Pleistocene sediments themselves attest to a time of limited ice cover in Greenland, with temperatures as much as 6-8 &amp;#176;C higher than present (e.g. Bennike et al., 2010).&lt;/p&gt;&lt;p&gt;We find that the northern Independence Fjord system must have formed by glacial erosion since the deposition of the marine late Pliocene-early Pleistocene sediments at ~2.5 Ma, in order to explain the current elevation of the sediments by erosion-induced isostatic uplift. In contrast, fjord formation in the outer parts of southward Scoresby Sund commenced prior to the Pleistocene, most likely in late Miocene, and continued throughout the Pleistocene with fjord formation progressing inland. Our results suggest that the inception of the Greenland Ice Sheet began in the central parts of Northeast Greenland before the Pleistocene and spread to North Greenland only at the onset of the Pleistocene.&amp;#160;&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;p&gt;Bennike, O., Knudsen, K.L., Abrahamsen, N., B&amp;#246;cher, J., Cremer, H., and Wagner, B., 2010, Early Pleistocene sediments on Store Koldewey, north&amp;#173;east Greenland: Boreas v. 39, p. 603&amp;#8211;619, https://doi.org /10.1111/j.1502-3885.2010.00147.x.&lt;/p&gt;

scholarly journals Quaternary observations in southern Peary Land, North Greenland

1976 ◽  
Vol 80 ◽  
pp. 15-17
Author(s):  
A Weidick
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Primary Objective ◽  
Drilling Operation ◽  
Ice Cap ◽  
History Of ◽  
Quaternary History ◽  
Work Done ◽  
North Greenland

A geological group consisting of the author and P. R.Dawes accompanied the 1975 Greenland Ice Sheet Programme's (GISP) ice drilling operation at Hans Tavsens Iskappe, south-westem Peary Land. The primary objective of the group was to investigate the Quaternary history of the area south of the ice cap as a supplement to the work done elsewhere in Peary Land by the various Peary Land Expeditions (Troelsen, 1952; Kirkeby, 1963: Fredskild, 1969), Operations Groundhog and Lead Dog (Stoertz & Needleman, 1957; Davies, 1972; Ahnert, 1960) and the British Joint Services Expedition (Dawes, 1970).

scholarly journals Investigating the glacial history of the northern sector of the Cordilleran Ice Sheet with cosmogenic 10Be concentrations in quartz

2010 ◽  
Vol 29 (25-26) ◽  
pp. 3630-3643 ◽  
Author(s):  
Arjen P. Stroeven ◽  
Derek Fabel ◽  
Alexandru T. Codilean ◽  
Johan Kleman ◽  
John J. Clague ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Glacial History ◽  
History Of ◽  
Cordilleran Ice Sheet ◽  
Cosmogenic 10Be ◽  
Northern Sector

scholarly journals How warm was Greenland during the last interglacial period?

2016 ◽  
Vol 12 (9) ◽  
pp. 1933-1948 ◽  
Author(s):  
Amaelle Landais ◽  
Valérie Masson-Delmotte ◽  
Emilie Capron ◽  
Petra M. Langebroek ◽  
Pepijn Bakker ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Ice Core ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Water Isotopes ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Last Interglacial Period ◽  
Ice Sheet Topography ◽  
North Greenland

Abstract. The last interglacial period (LIG, ∼ 129–116 thousand years ago) provides the most recent case study of multimillennial polar warming above the preindustrial level and a response of the Greenland and Antarctic ice sheets to this warming, as well as a test bed for climate and ice sheet models. Past changes in Greenland ice sheet thickness and surface temperature during this period were recently derived from the North Greenland Eemian Ice Drilling (NEEM) ice core records, northwest Greenland. The NEEM paradox has emerged from an estimated large local warming above the preindustrial level (7.5 ± 1.8 °C at the deposition site 126 kyr ago without correction for any overall ice sheet altitude changes between the LIG and the preindustrial period) based on water isotopes, together with limited local ice thinning, suggesting more resilience of the real Greenland ice sheet than shown in some ice sheet models. Here, we provide an independent assessment of the average LIG Greenland surface warming using ice core air isotopic composition (δ15N) and relationships between accumulation rate and temperature. The LIG surface temperature at the upstream NEEM deposition site without ice sheet altitude correction is estimated to be warmer by +8.5 ± 2.5 °C compared to the preindustrial period. This temperature estimate is consistent with the 7.5 ± 1.8 °C warming initially determined from NEEM water isotopes but at the upper end of the preindustrial period to LIG temperature difference of +5.2 ± 2.3 °C obtained at the NGRIP (North Greenland Ice Core Project) site by the same method. Climate simulations performed with present-day ice sheet topography lead in general to a warming smaller than reconstructed, but sensitivity tests show that larger amplitudes (up to 5 °C) are produced in response to prescribed changes in sea ice extent and ice sheet topography.

Sign in / Sign up

Export Citation Format

Share Document