A5086593577- Cryospheric studies and observations
- Winter Sports Injuries and Performance
- Landslides and related hazards
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Polar Research and Ecology
- Climate change and permafrost
- Marine animal studies overview
- Climate variability and models
- Atmospheric and Environmental Gas Dynamics
- Geological Studies and Exploration
- Marine and coastal ecosystems
- Icing and De-icing Technologies
- Metallurgical Processes and Thermodynamics
- Materials Engineering and Processing
- Methane Hydrates and Related Phenomena
- Geological and Geophysical Studies
University of Manitoba
2021-2025
National Centre for Earth Observation
2023-2025
College of Wooster
2019
University of Colorado Boulder
2016-2019
Cooperative Institute for Research in Environmental Sciences
2018-2019
Colgate University
2018
University of Colorado System
2014
Floating ice shelves of fast-flowing streams are prone to rift initiation and calving originating along zones rapid shearing at their margins. Predicting future ice-shelf destabilization under a warming ocean scenario, with the resultant reduced buttressing, faster flow, sea-level rise, therefore requires an understanding processes that thin weaken these shear Here, we use satellite data show high velocity gradients result in surface troughs margins streams. These advected into margins,...
Abstract. The Thwaites Eastern Ice Shelf (TEIS) buttresses the eastern grounded portion of Glacier through contact with a pinning point at its seaward limit. Loss this ice shelf will promote further acceleration Glacier. Understanding dynamic controls and structural integrity TEIS is therefore important to estimating Thwaites' future sea-level contribution. We present ∼ 20-year record change on that reveals governing shelf's past behaviour ongoing evolution. derived velocities from MODIS...
Abstract. The Thwaites Eastern Ice Shelf buttresses a significant portion of Glacier through contact with pinning point 40 km offshore the present grounding line. Predicting future rates Glacier’s contribution to sea-level rise depends on evolution this and resultant change in ice-shelf stress field since breakup Western Tongue 2009. Here we use Landsat-8 feature tracking ice velocity combination ice-sheet model perturbation experiments show how past changes flow have been governed large...
Abstract. Ice shelves play a key role in the dynamics of marine ice sheets by buttressing grounded and limiting rates flux to oceans. In response recent climatic oceanic change, fringing West Antarctic Sheet (WAIS) have begun fragment retreat, with major implications for ice-sheet stability. Here, we focus on Thwaites Eastern Shelf (TEIS), remaining pinned floating extension Glacier. We show that TEIS has undergone process fragmentation last 5 years, including brittle failure along shear...
Uncertainty about sea-level rise is dominated by uncertainty iceberg calving, mass loss from glaciers or ice sheets fracturing. Review of the rapidly growing calving literature leads to a few overarching hypotheses. Almost all occurs near just downglacier location where flows into an environment more favorable for so rate controlled primarily flow margin rather than Calving can be classified five regimes, which tend persistent, predictable, and insensitive small perturbations in velocity,...
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ABSTRACT Strain rates are fundamental measures of ice flow and used in a wide variety glaciological applications including investigations bed properties, calculations basal mass balance on shelves, constraints rheological models. However, despite their extensive application, strain calculated using methods length scales the details often not specified. In this study, we compare results nominal logarithmic strain-rate based satellite-derived velocity field Antarctic sheet generated from...
Abstract Basal channels, which are troughs carved into the undersides of ice shelves by buoyant plumes water, modulators ice-shelf basal melt and structural stability. In this study, we track evolution 12 large channels beneath Amundsen Bellingshausen seas region in West Antarctica using Landsat record since its start 1970s through 2020. We observe examples channel growth, interactions with features, systematic changes sinuosity that give insight life cycles channels. use last two decades...
Knowledge gaps about how the ocean melts Antarctica's ice shelves, borne from a lack of observations, lead to large uncertainties in sea level predictions. Using high-resolution maps underside Dotson Ice Shelf, West Antarctica, we reveal imprint that shelf basal melting leaves on ice. Convection and intermittent warm water intrusions form widespread terraced features through slow quiescent areas, while shear-driven turbulence rapidly smooth, eroded topographies outflow as well enigmatic...
Abstract Basal channels, which form where buoyant plumes of ocean water and meltwater carve troughs upwards into ice-shelf bases, are widespread on Antarctic ice shelves. The formation these features modulates basal melt by influencing the flow plumes, influences structural stability through concentration strain interactions with fractures. Because effects, because channels can change rapidly, timescales similar to those evolution, constraining impacts shelves is necessary for predicting...
ABSTRACT The surface of the Ross Ice Shelf (RIS) is textured by flow stripes, crevasses and other features related to ice deformation. Here, moderate resolution optical satellite images are used map classify regions RIS characterized different textures. Because textures arise from deformation, identify structural provinces with common deformation history. We four province types: associated large outlet glaciers, shear zones, extension downstream obstacles suture zones between upstream...
Abstract Rain-on-snow (ROS) events can have adverse impacts on high-latitude ungulate populations when rain freezes in the snowpack, forming ice layers that block access to winter forage. In extreme cases, ROS led mass die-offs. are linked advection of warm and moist air, associated with extratropical cyclones. However, these conditions common many precipitation events, challenging our understanding particular under which occur. This study uses Modern-Era Retrospective Analysis for Research...
Abstract West Antarctic ice-shelf thinning is primarily caused by ocean-driven basal melting. Here we assess ocean variability below Thwaites Eastern Ice Shelf (TEIS) and reveal the importance of local circulation sea-ice. Measurements obtained from two sub-ice-shelf moorings, spanning January 2020 to March 2021, show warming cavity an increase in meltwater fraction upper sub-ice layer. Combined with modelling results, our observations suggest that Pine Island feeds into TEIS cavity, adding...
Abstract. The Thwaites Eastern Ice Shelf (TEIS) buttresses the eastern grounded portion of Glacier through contact with a pinning point at its seaward limit. Loss this ice shelf will promote further acceleration Glacier. Understanding dynamic controls and structural integrity TEIS is therefore important to estimating Thwaites' future sea-level contribution. We present ~20-year record change on that reveals governing shelf's past behavior ongoing evolution. derived velocities from MODIS...
Antarctica's ice shelves play a critical role in modulating loss to the ocean by buttressing grounded upstream. With potential impact ice-shelf stability, persistent polynyas (open-water areas surrounded sea that occur across multiple years at same location) edge of many fronts are maintained winds and/or heat and locations strong ice–ocean–atmosphere interactions. However, situ observations sparse due logistical constraints collecting Antarctic field measurements. Here, we used wintertime...
Abstract. Ice shelves play a key role in the dynamics of marine ice sheets, by buttressing grounded and limiting rates flux to oceans. In response recent climatic oceanic change, fringing West Antarctic Sheet (WAIS) have begun fragment retreat, with major implications for sheet stability. Here, we focus on Thwaites Eastern Shelf (TEIS), remaining pinned floating extension Glacier. We show that TEIS has undergone process fragmentation last five years, including brittle failure along shear...
The Thwaites Eastern Ice Shelf stands as the last remaining floating extent of consequential Glacier in West Antarctica. In past, it has provided buttressing grounded glacier ice, but decade ice shelf undergone significant weakening that reduced its ability to buttress glacier. Important signs include: 1) flow measured by ground-based GPS shows continuous acceleration, nearly doubling speed from 1.65 m/d 2019 2.85 early 2023; 2) a recent breakout sea accelerated retreat at western calving...
Abstract. On Dotson Ice Shelf, Antarctica, ice velocities derived from satellite image pairs and in-situ GPS measurements reveal an oscillating flow pattern that is correlated with tide height. The tidally-affected of limited extent, in area near the Wunneberger Rock nunatak outflow Kohler Glacier. Comparing variations region’s velocity a series 16-day repeat-pass Landsat 8 spanning 2014–2020, 64-hour record 2022 CATS2008 TPXO9 tide-height models, indicates significant correlation between...
Abstract Rift propagation, rather than basal melt, drives the destabilization and disintegration of Thwaites Eastern Ice Shelf. Since 2016, rifts have episodically advanced throughout central ice-shelf area, with rapid propagation events occurring during austral spring. The ice shelf's speed has increased by ~70% this period, transitioning from a rate 1.65 m d −1 in 2019 to 2.85 early 2023 area. increase longitudinal strain rates near grounding zone led full-thickness melange-filled gaps...