Reconstructing the deglacial history of the Labrador Ice Dome on the Ungava Peninsula, Nunavik, Northern Canada

P Dunlop, Martin Roy, Hugo Dubé-Loubert

Research output: Contribution to conferenceAbstract

Abstract

The climate variability of the last 15,000 to 7,000 years is commonly linked to the drainage of large glacial lakes that developed at the margins of the decaying ice sheets of the last Ice Age. These large meltwater outbursts are known to have perturbed the North Atlantic Ocean circulation, which plays a fundamental role in regulating Earth’s climate. These former climate-forcing events are now under focus due to a growing number of studies showing that the present-day increase in freshwater releases from the melting of Greenland and other Arctic glaciers may potentially lead to a slowdown of the ocean thermohaline circulation and cause important climate feedbacks. This UK & Canada Arctic Partnership brings together researchers from Canada and the UK to work on a research program that will improve the accuracy of paleogeographic reconstructions in the Canadian Arctic in regions that participated in these large meltwater events by providing a comprehensive knowledge of ice-flow patterns and ice sheet dynamics in deglaciated terrains. The region surrounding Ungava Bay in north-central Quebec and Labrador occupies a strategic position to unravel these issues as it encompasses the zone of migration of the Labrador ice divide and most topographic depressions hosted glacial lakes. The region has a spectacular geomorphology characterized by various glacial/deglacial landforms as well as extensive shoreline sequences that record former ice sheet history and glacial lake levels. This northern area is the key focus for this research collaboration which aims to build a comprehensive understanding of former ice sheet retreat and the role deglaciation played in the development of glacial lakes and lake discharges in this Artic/sub-Arctic region. During the last deglaciation in Canada, the Labrador Ice Dome underwent a marked retreat of its south-southeastern margin towards northern latitudes, with the last ice sheet remnant resting on the center of the Ungava Peninsula in northern Nunavik. Although the temporal evolution of these ice sheet changes is well characterized in the south, the entire northern portion of the Labrador Sector of the Laurentide Ice Sheet remains unconstrained, mostly due to a lack of understanding on the spatial distribution of the various landforms created during ice marginal retreat which provide critical information on the pattern and timing of deglaciation. This project addresses this deficit by producing the first detailed glacial geomorphology map of the northern sector of the Ungava peninsula using high resolution satellite imagery and will age constrain ice sheet retreat across the peninsula using both Terrestrial Cosmogenic Nuclide (TCN) dating and Schmidt Hammer Exposure Dating (SHED) analysis on targeted deglacial landforms. Here we present our initial results of the mapping programme which captures the spatial distribution of glacial landforms on the Peninsula from the Puvirnituq/Akulivik region on coast of Hudson Bay to the center of the Peninsula east of the Pingualuit National Park. We also report the results from our fieldwork campaign that was conducted in Nunavik in summer 2018 to collect suitable samples to date deglaciation in this region for the first time using TCN and SHED analysis.
Original languageEnglish
Number of pages1
Publication statusPublished - 14 Dec 2018
EventArcticNet : Annual Scientific Meeting - Shaw Centre, Ottawa, Canada
Duration: 10 Dec 201814 Dec 2018
http://www.arcticnetmeetings.ca/asm2018/

Conference

ConferenceArcticNet
CountryCanada
CityOttawa
Period10/12/1814/12/18
Internet address

Keywords

  • Nunavik
  • Ungava
  • Deglaciation
  • Quebec
  • Laurentide Ice Sheet

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    Martin Roy

    Paul Dunlop (Host)

    22 Oct 201925 Oct 2019

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    Cite this

    Dunlop, P., Roy, M., & Dubé-Loubert, H. (2018). Reconstructing the deglacial history of the Labrador Ice Dome on the Ungava Peninsula, Nunavik, Northern Canada. Abstract from ArcticNet , Ottawa, Canada.