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Abstract Accelerated climate warming has caused the majority of marine-terminating glaciers in the Northern Hemisphere to retreat substantially during the twenty-first century. While glacier retreat and changes in mass balance are widely studied on a global scale, the impacts of deglaciation on adjacent coastal geomorphology are often overlooked and therefore poorly understood. Here we examine changes in proglacial zones of marine-terminating glaciers across the Northern Hemisphere to quantify the length of new coastline that has been exposed by glacial retreat between 2000 and 2020. We identified a total of 2,466 ± 0.8 km (123 km a⁻¹) of new coastline with most (66%) of the total length occurring in Greenland. These young paraglacial coastlines are highly dynamic, exhibiting high sediment fluxes and rapidly evolving landforms. Retreating glaciers and associated newly exposed coastline can have important impacts on local ecosystems and Arctic communities. 

Abstract High-latitude and altitude cold regions are affected by climate warming and permafrost degradation. One of the major concerns associated with degrading permafrost is thaw subsidence (TS) due to melting of excess ground ice and associated thaw consolidation. Field observations, remote sensing, and numerical modeling are used to measure and estimate the extent and rates of TS across broad spatial and temporal scales. Our new data synthesis effort from diverse permafrost regions of North America and Eurasia, confirms widespread TS across the panarctic permafrost domain with rates of up to 2 cm yr⁻¹in the areas with low ice content and more than 3 cm yr⁻¹in regions with ice-rich permafrost. Areas with human activities or areas affected by wildfires exhibited higher subsidence rates. Our findings suggest that permafrost landscapes are undergoing geomorphic change that is impacting hydrology, ecosystems, and human infrastructure. The development of a systematic TS monitoring is urgently needed to deliver consistent and continuous exchange of data across different permafrost regions. Integration of coordinated field observations, remote sensing, and modeling of TS across a range of scales would contribute to better understanding of rapidly changing permafrost environments and resulting climate feedbacks. 

This project is part of Navigating the New Arctic (NNA) which addresses converging scientific challenges in the rapidly changing Arctic. Specifically, the goal of this project, is to better understand the effects climate change imposes on society and the built environment and develop risk assessments for future adaptive planning. This dataset provides ground temperature data in the active layer and near-surface permafrost to provide a baseline for assessing the future changes in the near-surface temperatures in the natural and disturbed environment in the vicinity of the city of Fairbanks, Alaska, United States and the city of Whitehorse, Yukon, Canada. Collected ground temperature data are intended to help researchers, communities and public with ongoing activities to mitigate a threat of thawing permafrost on the local and regional scale, and to provide spatial data for validation of climate scenario models and temperature reanalysis approaches. 

Abstract The thawing of permafrost in the Arctic has led to an increase in coastal land loss, flooding, and ground subsidence, seriously threatening civil infrastructure and coastal communities. However, a lack of tools for synthetic hazard assessment of the Arctic coast has hindered effective response measures. We developed a holistic framework, the Arctic Coastal Hazard Index (ACHI), to assess the vulnerability of Arctic coasts to permafrost thawing, coastal erosion, and coastal flooding. We quantified the coastal permafrost thaw potential (PTP) through regional assessment of thaw subsidence using ground settlement index. The calculations of the ground settlement index involve utilizing projections of permafrost conditions, including future regional mean annual ground temperature, active layer thickness, and talik thickness. The predicted thaw subsidence was validated through a comparison with observed long-term subsidence data. The ACHI incorporates the PTP into seven physical and ecological variables for coastal hazard assessment: shoreline type, habitat, relief, wind exposure, wave exposure, surge potential, and sea-level rise. The coastal hazard assessment was conducted for each 1 km²coastline of North Slope Borough, Alaska in the 2060s under the Representative Concentration Pathway 4.5 and 8.5 forcing scenarios. The areas that are prone to coastal hazards were identified by mapping the distribution pattern of the ACHI. The calculated coastal hazards potential was subjected to validation by comparing it with the observed and historical long-term coastal erosion mean rates. This framework for Arctic coastal assessment may assist policy and decision-making for adaptation, mitigation strategies, and civil infrastructure planning. 

This project is part of Navigating the New Arctic (NNA) which addresses converging scientific challenges in the rapidly changing Arctic. Specifically, the goal of this project, is to better understand the effects climate change imposes on society and the built environment and develop risk assessments for future adaptive planning. This dataset provides ground temperature data in the active layer and near-surface permafrost to provide a baseline for assessing the future changes in the near-surface temperatures in the natural and disturbed environment in the vicinity of the city of Fairbanks, Alaska. Collected ground temperature data are intended to help researchers, communities and public with ongoing activities to mitigate a threat of thawing permafrost on the local and regional scale, and to provide spatial data for validation of climate scenario models and temperature reanalysis approaches. 

This paper presents the results of a community survey that was designed to better understand the effects of permafrost degradation and coastal erosion on civil infrastructure. Observations were collected from residents in four Arctic coastal communities: Point Lay, Wainwright, Utqiaġvik, and Kaktovik. All four communities are underlain by continuous ice-rich permafrost with varying degrees of degradation and coastal erosion. The types, locations, and periods of observed permafrost thaw and coastal erosion were elicited. Survey participants also reported the types of civil infrastructure being affected by permafrost degradation and coastal erosion and any damage to residential buildings. Most survey participants reported that coastal erosion has been occurring for a longer period than permafrost thaw. Surface water ponding, ground surface collapse, and differential ground settlement are the three types of changes in ground surface manifested by permafrost degradation that are most frequently reported by the participants, while houses are reported as the most affected type of infrastructure in the Arctic coastal communities. Wall cracking and house tilting are the most commonly reported types of residential building damage. The effects of permafrost degradation and coastal erosion on civil infrastructure vary between communities. Locations of observed permafrost degradation and coastal erosion collected from all survey participants in each community were stacked using heatmap data visualization. The heatmaps constructed using the community survey data are reasonably consistent with modeled data synthesized from the scientific literature. This study shows a useful approach to coproduce knowledge with Arctic residents to identify locations of permafrost thaw and coastal erosion at higher spatial resolution as well as the types of infrastructure damage of most concern to Arctic residents. 

Abstract Lakes are an important ecosystem component and geomorphological agent in northern high latitudes and it is important to understand how lake initiation, expansion and drainage may change as high latitudes continue to warm. In this study, we utilized Landsat Multispectral Scanner System images from the 1970s (1972, 1974, and 1975) and Operational Land Imager images from the 2010s (2013, 2014, and 2015) to assess broad-scale distribution and changes of lakes larger than 1 ha across the four permafrost zones (continuous, discontinuous, sporadic, and isolated extent) in western Alaska. Across our 68 000 km²study area, we saw a decline in overall lake coverage across all permafrost zones with the exception of the sporadic permafrost zone. In the continuous permafrost zone lake area declined by −6.7% (−65.3 km²), in the discontinuous permafrost zone by −1.6% (−55.0 km²), in the isolated permafrost zone by −6.9% (−31.5 km²) while lake cover increased by 2.7% (117.2 km²) in the sporadic permafrost zone. Overall, we observed a net drainage of lakes larger than 10 ha in the study region. Partial drainage of these medium to large lakes created an increase in the area covered by small water bodies <10 ha, in the form of remnant lakes and ponds by 7.1% (12.6 km²) in continuous permafrost, 2.5% (15.5 km²) in discontinuous permafrost, 14.4% (74.6 km²) in sporadic permafrost, and 10.4% (17.2 km²) in isolated permafrost. In general, our observations indicate that lake expansion and drainage in western Alaska are occurring in parallel. As the climate continues to warm and permafrost continues to thaw, we expect an increase in the number of drainage events in this region leading to the formation of higher numbers of small remnant lakes.