Glacier expansion on Baffin Island during early Holocene cold reversals

Crump, Sarah E.; Young, Nicolás E.; Miller, Gifford H.; Pendleton, Simon L.; Tulenko, Joseph P.; Anderson, Robert S.; Briner, Jason P.

doi:10.1016/j.quascirev.2020.106419

Cited by 11 publications

(9 citation statements)

References 96 publications

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“…9.3-9.0 ka BP and is thought to be driven by the 9.3 ka cooling event displayed in Greenland ice cores (Young et al, 2020a). The Qamanaarsuup Sermia moraine age (9.57 ± 0.38 ka BP) is, within uncertainties, synchronous with the 9.3 ka cooling event, but 10 Be-dated moraines in Baffin Bay consistently date to at or slightly after the 9.3 ka cooling event (Young et al, 2011b;Young et al, 2020a;Crump et al, 2020).…”

Section: Early Holocene Moraine Depositionmentioning

confidence: 86%

Cosmogenic isotope measurements from recently deglaciated bedrock as a new tool to decipher changes in Greenland Ice Sheet size

Young

Lesnek

Cuzzone

et al. 2020

Preprint

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Abstract. During the middle to late Holocene (8.2 ka BP to present), the Greenland Ice Sheet (GrIS) was smaller than its current configuration. Determining the exact dimensions of the Holocene ice-sheet minimum and the duration that the ice margin rested inboard of its current position remains challenging. Contemporary retreat of the GrIS from its historical maximum extent in southwestern Greenland is exposing a landscape that holds clues regarding the configuration and timing of past ice-sheet minima. To quantify the duration of the time the GrIS margin was near its modern extent we develop a new technique on Greenland that utilizes in situ cosmogenic 10Be-14C-26Al in bedrock samples that have become ice free only in the last few decades by the retreating ice-sheet margin at Kangiata Nunaata Sermia (n = 12 sites; KNS), southwest Greenland. To maximize the utility of this approach, we refine the deglaciation history of the region with stand-alone 10Be measurements (n = 49) and traditional 14C ages from sedimentary deposits contained in proglacial-threshold lakes. We combine our reconstructed ice-margin history in the KNS region with additional geologic records from southwestern Greenland and recent model simulations of GrIS change, to constrain the timing of the GrIS minimum in southwest Greenland, the magnitude of Holocene inland GrIS retreat, and explore the regional climate history influencing Holocene ice-sheet behavior. Our 10Be-14C-26Al measurements reveal that 1) KNS retreated behind its modern margin just before 10 ka, but likely stabilized near the present GrIS margin for several thousand years before retreating farther inland, and 2) pre-Holocene 10Be detected in several of our sample sites is most easily explained by several thousand years of surface exposure during the Last Interglaciation. Moreover, our new results indicate that the minimum extent of the GrIS likely occurred after ~ 5 ka, and the GrIS margin may have approached its eventual historical maximum extent as early as ~ 2 ka. Recent simulations of GrIS change are able to match the geologic record of ice-sheet change in regions dominated by surface mass balance, but produce a poorer model-data fit in areas influenced by oceanic and dynamic processes. Simulations that achieve the best model-data fit suggest that inland retreat of the ice margin driven by early to middle Holocene warmth may have been mitigated by increased precipitation. Triple 10Be-14C-26Al measurements in recently deglaciated bedrock provide a new tool to help decipher the duration of smaller-than-present ice over multiple timescales. Modern retreat of the GrIS margin in southwest Greenland is revealing a bedrock landscape that was also exposed during the migration of the GrIS margin towards its Holocene minimum extent, but has yet to tap into a landscape that remained ice covered throughout the entire Holocene.

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Section: Early Holocene Moraine Depositionmentioning

confidence: 86%

Cosmogenic isotope measurements from recently deglaciated bedrock as a new tool to decipher changes in Greenland Ice Sheet size

Young

Lesnek

Cuzzone

et al. 2020

Preprint

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“…On Cumberland Peninsula, the innermost pre-Neoglacial moraines are interpreted as Cockburn-equivalent moraines (Fig. 1A), correlated to the dated Cockburn moraines along the northeast and northern margins of the LIS (Miller and Dyke 1974;Andrews and Ives 1978;Margreth 2015;Crump et al 2020). Recent 10 Be cosmogenic exposure dating has identified a number of readvances in eastern Baffin Island (~11.8 ka, 10.3 ka, 9.2 ka) in addition to the prominent 9.3 ka and 8.2 6 2009).…”

Section: [Insert Figures 1 and 2]mentioning

confidence: 92%

“…It is noteworthy that many of the fiord-head moraines in the study region (Dyke 2013 a, b), including those in Kangert, Boas, and Mermaid fiords, and in Durban Harbour, remain undated, and thus a possible readvance and delta-building phase as late as the widespread glacial response to the 8.2 ka event (Young et al 2012(Young et al , 2020Crump et al 2020) cannot be ruled out. The lowstand date of c. 8.0 ka produced by the ICE-7G-NA (VM7) model (Fig.…”

Section: Depositional History and Chronologymentioning

confidence: 99%

“…Yet, without further information on the spatial distribution of submerged shorelines, the 5 throughout the overall glacial recession, during which the LIS, PIC and alpine glaciers re-advanced. Readvances occurred during the Younger Dryas (YD) cold interval (12.8-11.7 ka cal BP) and the Cockburn Substage (9.5-8.2 ka cal BP), including the 8.2 ka cold event (Briner et al 2009;Young et al 2012Young et al , 2020Margreth et al 2017;Crump et al 2020).…”

Section: [Insert Figures 1 and 2]mentioning

confidence: 99%

“…The Cockburn Substage was a major re-advance of alpine glaciers to the fiord heads and coast during the overall deglaciation (Andrews and Ives 1978). It deposited extensive lateral and end moraines associated with local readvances at many sites, particularly c. 9.3 ka and 8.2 ka (Young et al 2012(Young et al , 2020Margreth et al 2017;Crump et al 2020). On Cumberland Peninsula, the innermost pre-Neoglacial moraines are interpreted as Cockburn-equivalent moraines (Fig.…”

Section: [Insert Figures 1 and 2]mentioning

confidence: 99%

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Postglacial sea-level lowstand on Cumberland Peninsula, Baffin Island, Nunavut

et al. 2022

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This study investigates the postglacial sea-level history of eastern Cumberland Peninsula, a region of Baffin Island, Nunavut where submerged terraces were documented in the 1970s. The gradient in elevation of emerged postglacial marine-limit deltas and fiord-head moraines led Dyke (1979) to propose a conceptual model for continuous postglacial submergence of the eastern peninsula. Multibeam mapping over the past decade has revealed eight unequivocal submerged deltas at 19-45 m below [present] sea level (bsl) and other relict shore-zone landforms (boulder barricade, spits, and sill platform) at 16-51 m bsl. Over a distance of 115 km from Qikiqtarjuaq to Cape Dyer, the submerged coastal features increase in depth toward the east, with a slope (0.36 m/km), somewhat less than that of the marine-limit shoreline previously documented (0.58-0.62 m/km). The submerged ice-proximal deltas, deglacial ice limits, and radiocarbon ages constrain the postglacial lowstand between 9.9 and 1.4 ka cal BP. The glacial-isostatic model ICE-7G_NA (VM7) (Peltier 2020) computes a lowstand relative sea level at 8.0 ka, the depth of which increases eastward at 0.28 m/km. The difference between observed and model-derived lowstand depths ranges from 1 m in the west to 10 m in the east and the predicted tilt is significantly less than observed (p=0.0008). The model results, emerging data on Holocene glacial re-advances on eastern Baffin Island, and evidence for proglacial delta formation point to a Cockburn (9.5-8.2 ka) age for the lowstand, most likely later in this range. This study confirms the 1970s conceptual model of postglacial submergence in outer Cumberland Peninsula and provides field evidence for further refinement of glacial-isostatic adjustment models.

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A 5000‐year paleoclimate record from Nettilling Lake (Baffin Island) based on diatom assemblages and oxygen isotope composition

Narancic

Saulnier‐Talbot

Meyer

et al. 2021

J Quaternary Science

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Sedimentary diatoms have been used to quantitatively reconstruct climate-related variables, such as temperature at different timescales. Even though temperature is often less of a key driver of diatom ecology than other environmental parameters (water chemistry), diatom inference models have been shown to be reliable in deducing past temperature trends. In addition, the oxygen isotope composition (δ 18 O diatom ) preserved in buried diatom frustules has demonstrated its potential to reflect climatic and hydrological conditions at the time of frustule formation. This study combines results from both diatom-based climate proxies to reconstruct summer water and mean annual air temperatures, and hydrological trends in Nettilling Lake, Baffin Island, from ca. 5000 to 500 cal a BP. Diatom-inferred temperatures revealed an overall ca. 2 °C cooling throughout the Late-Holocene. The δ 18 O diatom values showed an increasing trend up to ca. 1900 cal a BP, where they reached their highest values (+24.8‰ at 15 cm) and thereafter decreased to their lowest values (+21.4‰ at 4 cm). These trends were linked to meltwater inflows associated with Penny Ice Cap thaw rate that was in turn controlled by regional climatic conditions which went from intensified cooling during the Neoglacial period to slight warming thereafter. Our results suggest that diatom-and diatom-isotope-based temperature and hydrological reconstructions can identify trends related to the natural climate system variability. The diatom oxygen isotopes are useful for paleoenvironmental studies of terrestrial aquatic ecosystems, but not for all hydrological systems are the ideal temperature proxy. Hence, the combination of proxies helps to disentangle temperature and hydrological effects for paleoclimatic reconstructions and may support future studies of postglacial environmental change in northern lakes.

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Glacier expansion on Baffin Island during early Holocene cold reversals

Cited by 11 publications

References 96 publications

Cosmogenic isotope measurements from recently deglaciated bedrock as a new tool to decipher changes in Greenland Ice Sheet size

Cosmogenic isotope measurements from recently deglaciated bedrock as a new tool to decipher changes in Greenland Ice Sheet size

Postglacial sea-level lowstand on Cumberland Peninsula, Baffin Island, Nunavut

A 5000‐year paleoclimate record from Nettilling Lake (Baffin Island) based on diatom assemblages and oxygen isotope composition

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