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Gabriel Wolken

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Subaerial landslides at the head of the Barry Arm fjord remain a tsunami threat for the Prince William Sound region in southern Alaska. Tasked RADARSAT-2 synthetic aperture radar (SAR) data from two ultrafine beam modes (2 m), U19 and U15, were used to measure landslide movement of slopes near the toe of the Barry Glacier between 21 May 2021 and 5 November 2021. Data were acquired every 24 days, with U19 beginning on 21 May 2021 and U15 beginning on 28 May 2021. For a few planned acquisition dates, scenes were not captured because of technical issues. Interferometric synthetic aperture radar (InSAR) deformation maps (interferograms) are provided in wrapped phase (line-of-sight (LOS) phase in radians between 0 and...
Abstract (from Wiley): Snow avalanches are a natural hazard in mountainous areas worldwide with severe impacts that include fatalities, damage to infrastructure, disruption to commerce, and landscape disturbance. Understanding long-term avalanche frequency patterns, and associated climate and weather influences, improves our understanding of how climate change may affect avalanche activity. We used dendrochronological techniques to evaluate the historical frequency of large magnitude avalanches (LMAs) in the high-latitude climate of southeast Alaska, United States. We collected 434 cross sections throughout six avalanche paths near Juneau, Alaska. This resulted in 2706 identified avalanche growth disturbances between...
Categories: Publication; Types: Citation
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2015JF003539/abstract): A quantitative understanding of snow thickness and snow water equivalent (SWE) on glaciers is essential to a wide range of scientific and resource management topics. However, robust SWE estimates are observationally challenging, in part because SWE can vary abruptly over short distances in complex terrain due to interactions between topography and meteorological processes. In spring 2013, we measured snow accumulation on several glaciers around the Gulf of Alaska using both ground- and helicopter-based ground-penetrating radar surveys, complemented by extensive ground truth observations. We found that SWE can be highly variable (40%...
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Two active landslides at and near the retreating front of Barry Glacier at the head of Barry Arm Fjord in southern Alaska (Figure 1) could generate tsunamis if they failed rapidly and entered the water of the fjord. Landslide A, at the front of the glacier, is the largest, with a total volume estimated at 455 M m3 (Dai et al, 2020). Historical photographs from Barry Arm indicate that Landslide A initiated in the mid twentieth century, but there was a large pulse of movement between 2010 and 2017 when Barry Glacier thinned and retreated from about 1/2 of the toe of Landslide A (Dai et al., 2020). The glacier has continued to retreat since 2017. Interferometric synthetic aperture radar (InSAR) investigations of the...
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Future Changes in Snow Avalanches in Southern Alaska
Ongoing climate change is impacting areas of snow and ice in high latitudes and high elevation areas and is thus anticipated to change the frequency and magnitude of snow and ice related hazards. In Alaska, snow avalanches are the deadliest natural hazard, and they affect a large portion of the state, significantly impacting the natural landscape, the built environment, and public safety. As climate warming continues, it is expected that Alaska’s vulnerability to avalanche hazards will also continue to increase. Currently, there is limited public awareness and available information to support adaptation, mitigation and preparedness efforts for these hazards. The goal of this project is to improve understanding...
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