An official website of the United States government
Abstract Permafrost thaw and thermokarst development pose urgent challenges to Arctic communities, threatening infrastructure and essential services. This study examines the reciprocal impacts of permafrost degradation and infrastructure in Point Lay (Kali), Alaska, drawing on field data from ∼60 boreholes, measured and modeled ground temperature records, remote sensing analysis, and community interviews. Field campaigns from 2022–2024 reveal widespread thermokarst development and ground subsidence driven by the thaw of ice-rich permafrost. Borehole analysis confirms excess-ice contents averaging ∼40%, with syngenetic ice wedges extending over 12 m deep. Measured and modeled ground temperature data indicate a warming trend, with increasing mean annual ground temperatures and active layer thickness (ALT). Since 1949, modeled ALTs have generally deepened, with a marked shift toward consistently thicker ALTs in the 21st century. Remote sensing shows ice wedge thermokarst expanded from <5% in 1949 to >60% in developed areas by 2019, with thaw rates increasing tenfold between 1974 and 2019. In contrast, adjacent, undisturbed tundra exhibited more consistent thermokarst expansion (∼0.2% yr−1), underscoring the amplifying role of infrastructure, surface disturbance, and climate change. Community interviews reveal the lived consequences of permafrost degradation, including structural damage to homes, failing utilities, and growing dependence on alternative water and wastewater strategies. Engineering recommendations include deeper pile foundations, targeted ice wedge stabilization, aboveground utilities, enhanced snow management strategies, and improved drainage to mitigate ongoing infrastructure issues. As climate change accelerates permafrost thaw across the Arctic, this study highlights the need for integrated, community-driven adaptation strategies that blend geocryological research, engineering solutions, and local and Indigenous knowledge.
more »
« less
Infrastructure Development and Ice Wedge Thermokarst Formation in Point Lay (Kali), Alaska between 1949 and 2019
This dataset documents changes in infrastructure development and associated ice wedge thermokarst formation in Point Lay (Kali), Alaska, between 1949 and 2020. The data include vector-based Geographic Information System (GIS) layers derived from high-resolution remote sensing imagery and historical aerial photographs for three key time points: 1949, 1974, and 2019/20. Infrastructure features (e.g., roads, runways, gravel pads, and buildings) were manually digitized, and the extent of ice wedge thermokarst was mapped using detailed image interpretation techniques at 1:500 scale. The dataset supports spatial analysis of thermokarst expansion in relation to anthropogenic disturbance and surface development. Findings reveal a near tenfold increase in ice wedge thermokarst extent in developed areas between 1974 and 2019, with minimal changes in adjacent undisturbed tundra, underscoring the synergistic impact of infrastructure and climate warming on permafrost degradation. These data provide a valuable baseline for tracking permafrost-related landscape changes and informing adaptation strategies in Arctic communities experiencing thaw-related infrastructure challenges.
more »
« less
- Award ID(s):
- 2336164
- PAR ID:
- 10611066
- Publisher / Repository:
- NSF Arctic Data Center
- Date Published:
- Subject(s) / Keyword(s):
- Arctic Thermokarst Permafrost Infrastructure
- Format(s):
- Medium: X Other: text/xml
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Environmental impact assessments for new Arctic infrastructure do not adequately consider the likely long-term cumulative effects of climate change and infrastructure to landforms and vegetation in areas with ice-rich permafrost, due in part to lack of long-term environmental studies that monitor changes after the infrastructure is built. This case study examines long-term (1949–2020) climate- and road-related changes in a network of ice-wedge polygons, Prudhoe Bay Oilfield, Alaska. We studied four trajectories of change along a heavily traveled road and a relatively remote site. During 20 years prior to the oilfield development, the climate and landscapes changed very little. During 50 years after development, climate-related changes included increased numbers of thermokarst ponds, changes to ice-wedge-polygon morphology, snow distribution, thaw depths, dominant vegetation types, and shrub abundance. Road dust strongly affected plant-community structure and composition, particularly small forbs, mosses, and lichens. Flooding increased permafrost degradation, polygon center-trough elevation contrasts, and vegetation productivity. It was not possible to isolate infrastructure impacts from climate impacts, but the combined datasets provide unique insights into the rate and extent of ecological disturbances associated with infrastructure-affected landscapes under decades of climate warming. We conclude with recommendations for future cumulative impact assessments in areas with ice-rich permafrost.more » « less
-
Ice-wedge thermokarst has played an important role in permafrost evolution, and numerous cycles of ice-wedge formation/degradation have occurred through the Quaternary history. Studies of ice-wedge degradation help to explain processes of past ice-wedge thermokarst and predict its future consequences. We developed a conceptual model of ice-wedge degradation/stabilization, which is based on the dynamics of the intermediate layer of the upper permafrost. This model explains high resilience of ice-wedge systems and low probability of formation of large thaw lakes in the continuous permafrost zone. Absence of the intermediate layer at the time of yedoma accumulation and increased precipitation caused very high activity of thaw-lake formation during the Pleistocene/Holocene transition.more » « less
-
Cumulative impact assessments (CIAs) for new Arctic oilfields have not adequately addressed the potential landscape impacts of climate change or the indirect impacts of infrastructure in areas with ice-rich permafrost (IRP) (e.g., Raynolds et al. 2020). The main goals of this paper are: (1) trace the history of remote sensing for assessing past cumulative impacts in the Prudhoe Bay Oilfield (PBO), Alaska; (2) discuss some promising new remote-sensing and modeling tools; and (3) point toward improved capability to predict future changes. We first define IRP and cumulative impacts (CIs) and distinguish direct impacts (footprint) of infrastructure from the indirect impacts that follow construction. Aerial photographs (U.S. Navy 1948–1949) provided images of PBO landscapes before development occurred. The oil industry initiated annual high-resolution aerial-photograph missions of the PBO in 1968. In the same year, the International Biological Program (IBP) Tundra Biome started geoecological investigations that used these images to map landforms, soils, and vegetation of the PBO (Walker et al. 1980). The maps were later adapted to GIS approaches in three highly impacted 25-km2 areas of the PBO, which included several years of changes to tundra areas adjacent to infrastructure (Walker et al. 1987). The National Research Council later updated these three landscape-scale maps to 2001 and contracted the oil companies and Quantum Spatial Inc. to produce a regional-scale historical analysis of the network of roads, pipelines and other forms of infrastructure in all the North Slope Oilfields (NRC 2003). The regional- and landscape-scale maps used for NRC analysis were updated again in 2010 when unexpected rapid expansion of ice-wedge thermokarst was detected (Raynolds et al. 2014, 2016). Up to this time, CIAs of the PBO relied on aerial photographs and maps produced by the oil industry. The spatial resolution of available satellite-based remote-sensing data was insufficient to discern the details of periglacial landforms (e.g., ice-wedge polygons and nonsorted circles) or of roads, pipelines, or changes to land surfaces adjacent to infrastructure. Industry-sponsored studies that used remote-sensing products included studies of oil-pipeline spills, reserve-pits leaks (e.g., Jorgenson et al. 1995), off-road vehicles trails, and recovery following removal of gravel pads. Highlighted studies for this talk include a new NSF project that is part of the NSF Navigating the New Arctic initiative that is using integrated ground-based studies, advanced remote-sensing tools, and improved modeling approaches to examine climate- and infrastructure-related changes (Walker et al. 2022, Bergstedt 2022). Other projects that use PBO datasets for calibration, include an analysis of long-term impacts from a catastrophic flood (Shur et al. 2016, Zwieback et al. 2021) and studies that are using massive amounts of high-resolution imagery and pattern-recognition tools to detect and map ice-wedge polygons, water bodies, and infrastructure across the circumpolar Arctic (Bartsch et al. 2020; Witherrana et al. 2021). These tools combined with improved modeling approaches that bridge the gap between regional and engineering scales (e.g., Deimling et al. 2021) promise to greatly improve our ability to predict and monitor future infrastructure and landscape changes in areas with IRP.more » « less
-
Ice-wedge polygon (IWP) is a landform found in landscapes underlain by permafrost. IWPs form due to the development of ice wedges, where each IWP is bounded by ice wedges. Ice wedges form due to repeated cracking of the soil during winter and by snowmelt water infiltrating into the cracks and freezing. Repeated over thousands of years, the process results in ice wedges several 10s of feet deep. The melting of the top of the ice wedge results in ground subsidence and depending how extensive the thaw is across the landscape, new ponds or lateral drainage channels form. This data collection supported an assessment of the length of the ice wedge network in the Barnard River watershed (10,540 km2), Banks Island, Canada. The data collection is derived from the pan-Arctic map of ice-wedge polygons (Witharana et al. 2023, Ice-wedge polygon detection in satellite imagery from pan-Arctic regions, Permafrost Discovery Gateway, 2001-2021. Arctic Data Center. doi:10.18739/A2KW57K57), which used Maxar satellite imagery from 2010-2020 for Banks Island. Two types of datasets are included: (1) Polyline shapefile of mapped ice wedge centerlines. This dataset was produced with an approach adopted from Ulrich, Mathias, et al. "Quantifying wedge‐ice volumes in Yedoma and thermokarst basin deposits." Permafrost and Periglacial Processes 25.3 (2014): 151-161. A buffer that represents widths at the top of ice wedges is created around each IWP. A buffer width of 5 meters was chosen, since this allowed buffers of adjacent polygons to overlap. These buffers are then skeletonized in order to trace their centerlines, which ultimately represents the network of ice-wedges that form the IWPs in a landscape. (2) Polygon shapefile of IWP coverage (as percentage of land cover within 1 kilometer (km) x 1 km rectangular grid cells) across the 10,540 km2 Bernard River Watershed, Banks Island, Canada. Code for ice-wedge centerline extraction can be found at https://github.com/PermafrostDiscoveryGateway/IW-Network-Extraction. This data collection accompanies the manuscript published in Nature Water (Liljedahl, A.K., Witharana, C., and Manos, E., 2024. The Capillaries of the Arctic Tundra. Nature Water, doi:10.1038/s44221-024-00276-9) and the geospatial data is available to view in the Permafrost Discovery Gateway.more » « less
