Post-fire debris flows and glacial-lake outburst floods are proving to be archetypal cascading hazards, in which one disturbance primes or triggers the next. Building on our outburst-flood and cascading-hazards work, we aim to quantify and forecast these hazard chains (for example, glacier retreat exposing erodible sediment, feeding lake growth, leading to an outburst, and on to downstream debris flows and floods) while identifying the positive feedbacks that amplify them and the negative feedbacks that damp them. (Yanites et al., 2025; Rick et al., 2023; McGrath et al., 2026)
The ultimate goal is to translate an upstream change or disturbance, whether deglaciation or wildfire, into actionable, community-scale hazard information.
References
2026
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Rapid ice-marginal lake growth in Alaska driven by glacier retreat through bed overdeepenings
Daniel McGrath, Louis Sass, William H. Armstrong, and 2 more authors
Proceedings of the National Academy of Sciences, Mar 2026
The number and cumulative area of ice-marginal lakes have expanded globally in recent decades, with many lakes residing in glacier-bed overdeepenings, which are subglacial basins formed through preferential glacial erosion. However, current lake expansion rates, key drivers of expansion, and maximum future lake extents are poorly quantified. This is notable because glacial lakes pose hazards, alter hydrologic and ecological systems, and, in some cases, accelerate glacier flow and retreat. Here, we quantify recent ice-marginal lake growth and use existing ice thickness and topographic data to map glacier-bed overdeepenings in Alaska as a predictor of recent and future locations of lake growth. Ice-marginal lakes in the region grew by +156 km2 (26 km2 y−1) between 2018 and 2024, representing a 50% increase relative to the 2009–2018 rate. Eighty percent of lake growth since 2018 occurred in mapped glacier-bed overdeepenings. Approximately 4,250 km2 (2,966 to 5,503 km2 accounting for ± ice thickness uncertainty) of the overdeepened area is connected to an ice-marginal lake, indicating the potential for more than fourfold lake growth of existing lakes as glaciers retreat. An additional 14,500 km2 (12,469 to 17,134 km2) of remaining glacier area resides on glacier-bed overdeepenings not connected to existing lakes, highlighting the potential for substantial new lake development. Velocities from lake-terminating glaciers show clear passive and dynamic endmembers on a continuum of glacier–lake coupling. Glaciers with ice-marginal lakes thinned 23 to 54% more than glaciers of similar area without lakes, underscoring the critical importance of dynamic glacier–lake coupling on the evolution of glaciers in Alaska.
2025
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Cascading land surface hazards as a nexus in the Earth system
Brian J. Yanites, Marin K. Clark, Joshua J. Roering, and 17 more authors
Science, Jun 2025
This Review synthesizes progress and outlines a new framework for understanding how land surface hazards interact and propagate as sediment cascades across Earth’s surface, influenced by interactions among the atmosphere, biosphere, hydrosphere, and solid Earth. Recent research highlights a gap in understanding these interactions on human timescales, given rapid climatic change and urban expansion into hazard-prone zones. We review how surface processes such as coseismic landslides and post-fire debris flows form a complex sequence of events that exacerbate hazard susceptibility. Moreover, innovations in modeling, remote sensing, and critical zone science can offer new opportunities for quantifying cascading hazards. Looking forward, societal resilience can increase by transforming our understanding of cascading hazards through advances in integrating data into comprehensive models that link across Earth systems.
2023
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Unchanged frequency and decreasing magnitude of outbursts from ice-dammed lakes in Alaska
B. Rick, D. McGrath, S. W. McCoy, and 1 more author
Nature Communications, Oct 2023
Number: 1
Glacial lakes can form and grow due to glacial retreat, and rapid lake drainage can produce destructive floods. Outburst flood compilations show a temporal increase in frequency; however, recent studies highlight the role of observational bias, creating uncertainty about current and future glacial-lake hazards. Here, we focus on the Alaska region, which generated a third of previously documented outbursts globally. Using multitemporal satellite imagery, we documented 1150 drainages from 106 ice-dammed lakes between 1985 and 2020. Documented events became more frequent over time, however, accounting for increasing image availability reveals no significant increase occurred. Most lakes decreased in area and volume, suggesting a reduction in regional flood hazard. Our satellite-based approach documented 60% more events in a 35-year period than had previously been documented over 100 years. This suggests that outburst floods have historically been underreported and warrants systematic study of other regions.