Articles tagged with: northern Canada

  • New research finds evidence of climate-driven changes to northern lakes

    Across the Old Crow Flats in the northern Yukon, lakes are telling a story of climate-driven change.

    The traditional territory of the Vuntut Gwitchin First Nation (VGFN), the Old Crow Flats is recognized as a Ramsar Wetland of International Importance thanks to its more than 8,000 thermokarst lakes (up to 15 square kilometres) and ponds. Thermokarst lakes are formed by thawed permafrost and can be prone to drainage if they expand into low-lying areas.

    Kevin Turner, an Associate Professor in Brock’s Department of Geography and Tourism Studies and Fulbright Canada Research Chair in Arctic Studies at the University of Washington, has studied the area since 2007, and he says that warmer temperatures, longer summers and more rain are “priming this important landscape for continued climate-driven landscape change.”

    In a new paper with Lauren A. MacDonald, who was a post-doctoral research fellow at Brock in fall 2020, as well as researchers from Wilfrid Laurier University, University of Waterloo and Parks Canada, Turner and his team share an analysis of water samples suggesting significant trends toward increased rainfall in the area, which could affect drainage in the shallow lakes and cause changes to soil stability along shorelines.

    The research, conducted under the direction of the Vuntut Gwitchin Government and the North Yukon Renewable Resources Council, saw sampling take place from 14 lakes in the Old Crow Flats two to three times per year from 2007 to 2019.

    Kevin Turner collects water samples for analysis from a thermokarst lake in Old Crow Flats. (Photo courtesy of Luke Gray)

    The samples produced a 13-year record that the research team has analyzed using water isotope tracers to distinguish between input sources, such as rainfall and snow melt, and also to track water losses due to evaporation.

    “There is more than meets the eye with these results, as they represent a status indicator of the increasing vulnerability of this area to drastic change,” says Turner. “For example, permafrost, which holds the landscape intact, degrades more during warmer and wetter conditions, which can lead to more shoreline slumping and rapid drainage of lakes into the river network.”

    These changes to the landscape can disrupt ecosystems, affecting plants and wildlife and interfering with traditional ways of life — a trend already recognized by the VGFN.

    “Findings complement the traditional knowledge of the VGFN, who have observed changes in climate and landscape characteristics during recent decades and have recently declared a climate emergency,” says Turner.

    Isotopic evidence of increasing water abundance and lake hydrological change in Old Crow Flats, Yukon, Canada” was published in Environmental Research Letters in late November. Turner says that its findings demonstrate why collaboration and co-operation in research is so important.

    “This research showcases the value of innovative and collaborative long-term monitoring programs in these important and remote areas of the North where the impacts of climate change are heightened,” he says.

    STORY REPOSTED FROM THE BROCK NEWS

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  • New paper by Kevin Turner “Isotopic evidence of increasing water abundance and lake hydrological change in Old Crow Flats, Yukon, Canada”

    A new paper titled, “Isotopic evidence of increasing water abundance and lake hydrological change in Old Crow Flats, Yukon, Canada” co-authored by GeoTour Associate Professor, Dr. Kevin Turner, was recently published in Environmental Research Letters.

    Abstract:
    Lake-rich northern permafrost landscapes are sensitive to changing climate conditions, but ability to track real-time and potentially multiple hydrological responses (e.g. lake expansion, drawdown, drainage) is challenging due to absence of long-term, sustainable monitoring programs in these remote locations. Old Crow Flats (OCF), Yukon, is a Ramsar Wetland of International Importance where concerns about low water levels and their consequences for wildlife habitat and traditional ways of life prompted multidisciplinary studies during the International Polar Year (2007–2008) and led to the establishment of an aquatic ecosystem monitoring program. Here, we report water isotope data from 14 representative thermokarst lakes in OCF, the foundation of the monitoring program, and time-series of derived metrics including the isotope composition of input waters and evaporation-to-inflow ratios for a 13 year period (2007–2019). Although the lakes spanned multiple hydrological categories (i.e. rainfall-, snowmelt- and evaporation-dominated) based on initial surveys, well-defined trends from application of generalized additive models and meteorological records reveal that lakes have become increasingly influenced by rainfall, and potentially waters from thawing permafrost. These sources of input have led to more positive lake water balances. Given the documented role of rainfall in causing thermokarst lake drainage events in OCF and elsewhere, we anticipate increased vulnerability of lateral water export from OCF. This study demonstrates the value of long-term isotope-based monitoring programs for identifying hydrological consequences of climate change in lake-rich permafrost landscapes.

    Reference:
    MacDonald, L.A., Turner, K.W., McDonald, I., Kay, M.L., Hall, R.I., and Wolfe, B.B. (2021). Isotopic evidence of increasing water abundance and lake hydrological change in Old Crow Flats, Yukon, Canada. Environmental Research Letters, 16(12): online.

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  • Brock prof to talk climate change with Chief of Vuntut Gwitchin Government

    Residents of the Vuntut Gwitchin First Nation in Old Crow, Yukon are living on the frontline of climate change, witnessing dramatic landscape changes in the Arctic due to rising temperatures.

    Under the leadership of Dana Tizya-Tramm, Chief of the Vuntut Gwitchin Government, Yukon was the first Indigenous community to draft a climate change emergency declaration, Yeendoo Diinehdoo Ji’heezrit Nits’oo Ts’o’ Nan He’aa (or After Our Time, How Will the World Be?) in 2019.

    Brock University Associate Professor in Geography and Tourism Studies Kevin Turner is very familiar with the dramatic response of the landscape to climate change on the traditional territory of the Vuntut Gwitchin First Nation.

    Researching the area of Old Crow, Yukon, for over a decade, he continues to monitor landscape changes including landslides, vegetation change, lake drainage and fire. His research integrates chemical analyses of water and sediment to evaluate impacts of changing landscape features on lakes and rivers.

    Turner, who is Fulbright Canada Research Chair in Arctic Studies at the University of Washington, will be sitting down with Chief Tizya-Tramm for a “fireside chat” hosted by the World Affairs Council at a virtual public lecture Tuesday, Feb. 9 from 7 to 8 p.m.

    Turner and Tizya-Tramm will discuss emerging issues and priorities identified by the Vuntut Gwitchin First Nation in the face of global challenges.

    Diverse topics will include efforts to conserve the Porcupine Caribou Herd, adjustments during a pandemic, and pathways for unifying traditional insight of changing climate and landscapes with ongoing science-based monitoring approaches.

    “I’m looking forward to it, and in particular discussions of bringing together science-based research and traditional knowledge for the benefits of those most influenced by climate change,” says Turner.

    For more information and to register, click here.

    FROM THE BROCK NEWS

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  • New research uses leading-edge methods to track a retrogressive thaw slump in Old Crow Flats, Yukon

    Remote sensing graphics from research paper showing research location in Old Crow Flats, Yukon

    A new paper authored by Geography and Tourism Studies Associate Professor, Dr. Kevin Turner, and Geography alumni Michelle Pearce and Daniel Hughes titled “Detailed Characterization and Monitoring of a Retrogressive Thaw Slump from Remotely Piloted Aircraft Systems and Identifying Associated Influence on Carbon and Nitrogen Export” has been published in Remote Sensing. This paper is open-access and available to download here.

    Abstract:
    Ice-rich permafrost landscapes are sensitive to ongoing changes in climate. Permafrost retrogressive thaw slumps (RTSs) represent one of the more abrupt and prolonged disturbances, which occur along Arctic river and lake shorelines. These features impact local travel and infrastructure, and there are many questions regarding associated impacts on biogeochemical cycling. Predicting the duration and magnitude of impacts requires that we enhance our knowledge of RTS geomorphological drivers and rates of change. Here we demonstrate the utility of remotely piloted aircraft systems (RPAS) for documenting the volumetric change, associated drivers and potential impacts of the largest active RTS along the Old Crow River in Old Crow Flats, Yukon, Canada. RPAS surveys revealed that 29,174 m3 of sediment was exported during the initial evacuation in June 2016 and an additional 18,845 m3 continued to be exported until June 2019. More sediment export occurred during the warmer 2017 summer that experienced less cumulative rainfall than summer 2018. However, several rain events during 2017 were of higher intensity than during 2018. Overall mean soil organic carbon (SOC) and total nitrogen (TN) within sampled thaw slump sediment was 1.36% and 0.11%, respectively. A combination of multispectral, thermal and irradiance (derived from the RPAS digital surface model) data provided detailed classification of thaw slump floor terrain types including raised dry clay lobes, shaded and relatively stable, and low-lying evacuation-prone sediments. Notably, the path of evacuation-prone sediments extended to a series of ice wedges in the northern headwall, where total irradiance was highest. Using thaw slump floor mean SOC and TN values in conjunction with sediment bulk density and thaw slump fill volume, we estimated that 713 t SOC and 58 t TN were exported to the Old Crow River during the three-year study. Findings showcase the utility of high-resolution RPAS datasets for refining our knowledge of thaw slump geomorphology and associated impacts.

    Citation:
    Turner K.W., Pearce M.D., and Hughes D.D. (2021). Detailed Characterization and Monitoring of a Retrogressive Thaw Slump from Remotely Piloted Aircraft Systems and Identifying Associated Influence on Carbon and Nitrogen Export. Remote Sensing, 13(2):171. https://doi.org/10.3390/rs13020171

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  • New book chapter examines the changing ecology of the Arctic from a paleoenvironmental perspective

    Arctic Ecology Book Cover

    Dr. Michael Pisaric has published a new chapter in the book Arctic Ecology titled “Arctic Ecology – A Paleoenvironmental Perspective”.

    In the absence of measured climate and ecological data records, paleoecology, and paleoclimatology provide unique opportunities to examine ecological and climatic conditions across long timescales and provide much needed long‐term context. Across the Arctic there are numerous ecological problems affecting the biota and landscapes of this environmentally sensitive region. Climate change is chief amongst these. This chapter examines the changing ecology of the Arctic from a paleoenvironmental perspective. Using examples from studies throughout the circumpolar Arctic, the changing ecology of the Arctic is examined across longer timescales than typically considered in ecological studies. While instrumental records of climatic change in the Arctic are generally short, dendrochronology can provide key insights into climate variability during the past several centuries to millennia. There are many types of natural archives of ecological and environmental change from marine terrestrial environments in the Arctic.

    Citation:

    Pisaric, M., & Smol, J.P. (2021). Arctic Ecology – A Paleoenvironmental Perspective. Pages 23-55 in D.N. Thomas (Ed.) Arctic Ecology. Wiley. https://doi.org/10.1002/9781118846582.ch2

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  • Dr. Kevin Turner returns from fieldwork in northern Yukon

    Dr. Kevin Turner and graduate students, Joe Viscek and Brent Thorne, recently returned from completing fieldwork in northern Yukon where they’re investigating the influence of changing climate and landscape conditions (fire and erosion) on lakes and rivers. Here are some photos from their time in the field. Learn more about Dr. Turner’s research.

    Kevin Turner working in the field

    Kevin Turner doing fieldwork in the Yukon

    Joe Viscek doing fieldwork in the Yukon with Kevin Turner

    Brent Thorne doing fieldwork in the Yukon with Kevin Turner

    Kevin Turner - fieldwork photo from the Yukon

    Photos by Kevin Turner and Brent Thorne.

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