Harnessing Big Data for understanding termini
Using the enormous archive of existing satellite, model, and other data we can produce unprecedented time series of glacier change. On the right are two images of Greenland showing the number of images available for each glacier terminus spanning 1985-2021. Using machine learning, we have picked glacier termini in nearly 300,000 of these images. We will use these data along with environmental/glacier data to perform machine-enabled near-term prediction of glacier termini.
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Current Projects:
Machine-enabled modeling of terminus ablation for Greenland's outlet glaciers (funded by the National Science Foundation)
Collaborators: Kevin Shionalyn, Denis Felikson, Leigh Stearns, and Daniel Trugman
The goal of this project is to classify glacier termini by the processes that dominate their control. This will be accomplished using machine learning to accurately predict glacier terminus change over time. Model results will be used in predictive ice sheet models to improve estimates of future mass loss for Greenland.
Terminus change over time enabled from an automated data extraction pipeline (funded by NASA)
Collaborators: Enze Zhang, Sophie Goliber, Taryn Black, and Daniel Trugman
This project made use of hand-picked glacier termini collected, cleaned, and homogenized from across the glaciology research community to train a machine learning model to pick the most complete glacier terminus record for Greenland. These data are used in a range of projects including examining terminus standstill bed topography and changes in terminus morphology over time to reveal calving processes.
Active Glacial Sedimentation
With the unique AUV/ROV Nereid Under Ice (NUI) from WHOI and funding from the Keck Foundation, we will be able to acquire the first high-resolution data and sampling of sediments at active glacier termini. The project goal is to quantify rates and processes of sedimentation at termini and to link those to rates and processes of ice dynamics. We will deploy the NUI at three glaciers in Greenland that exhibit unique characteristics and divergent recent dynamic histories. Observations will be used to constrain coupled sediment-ice sheet models.
Current Projects:
Submersibles in the icy deep - Exploring sediment-ice sheet interactions (funded by the W.M. Keck Foundation)
Collaborating with Sean Gulick, John Goff, John Jaeger, Tim Bartholomaus, Mike Jakuba
This project aims to use a remotely operated vehicle to quantify the rates and processes contributing to moraine-building at active glacier termini in Greenland. Press release
Ice-Ocean Interactions
The Greenland Ice Sheet contains ~280 fast-flowing marine-terminating glaciers with a high degree of heterogeneity across a range of parameters including discharge, thickness, basal conditions, terminus conditions, and topography. Our work focuses on understanding the processes occurring in the submarine terminus zone and how these processes influence upstream ice dynamics as well as fjord circulation and sea-level.
Current Projects:
Using acoustic sensors to understand buoyant plumes in Alaska (funded by the Institute for Geophysics Blue Sky program)
Collaborating with Preston Wilson and Matt Zeh
This project makes use of acoustic sensors to capture noise in glacier fjords and quantify noise sources as they relate to ice-ocean interactions in Alaska.
Revealing the processes controlling outlet glacier seasonality with ICESat-2 (NASA-ICESat-2)
Collaborating with Denis Felikson and Bea Csatho
This project uses altimetry and models to understand the seasonal dynamics of outlet glaciers in Greenland. AGU abstract
Past Projects:
ICESat-2-enabled understanding of Greenland tidewater glacier dynamics (funded by NASA-Cryospheric Sciences)
Collaborating with Tim Bartholomaus
This project makes use of altimetry and other elevation data to determine how glacier termini have adjusted to climate over time.
Physical controls on ocean-terminating glacier variability in Central West Greenland (funded by NASA-Interdisciplinary Research in Earth Science)
Collaborating with Leigh Stearns, David Sutherland, Emily Shroyer, and Jonathan Nash
Field, model, and remote-sensing of ice-ocean interactions led to increased knowledge of submarine terminal processes and fjord-scale dynamics.
Ice sheet hydrology
Around the ice sheet margins melt exceeds local storage capacity and the vast majority of surface meltwater is efficiently routed to the ice-bed interface through moulins. The spring onset of meltwater flux to the bed raises subglacial water pressure at the ice-bed interface because of limited water storage capacity, and decreases friction at the bed, facilitating faster ice flow. Our work focuses on understanding the subglacial hydraulic system including the coupled flow of water and sediments.
Current Projects:
Revealing the processes controlling outlet glacier seasonality with ICESat-2 (NASA-ICESat-2)
Collaborating with Denis Felikson and Bea Csatho
This project uses altimetry and models to understand the seasonal dynamics of outlet glaciers in Greenland. AGU abstract
Past Projects:
Subglacial controls on Greenland Ice Sheet marginal acceleration (NSF-Arctic Natural Sciences)
Collaborating with Martin Lüthi, Bob Hawley, Tom Neumann, and Matt Hoffman
This project used modeling and borehole geophysics to directly measure surface, englacial, and subglacial processes in Greenland.
Greenland subglacial water pressure and its impact on ice flow (National Geographic Society)
Collaborating with Jason Gulley
Adding englacial observations greatly improved our ability to interpret subglacial hydrology conditions.
The importance of meltwater to the peripheral thinning of Greenland (NASA-Cryospheric Sciences)
Collaborating with Tom Neumann
GPS and radar-observed englacial and subglacial hydrology for Greenland’s ablation zone led to improvements in modeling.
Ice Sheet History
Using ice-penetrating radar, we can examine ice sheet stratigraphy and basal conditions to understand past configurations of the ice sheet, how bed conditions change over time, and englacial processes.
Selected publications:
J. MacGregor, M. Fahnestock, G. Catania, A. Aschwanden, G. Clow, W. Colgan, S. Gogineni, M. Morlighem, S. Nowicki, J. Paden, S. Price, H. Seroussi, 2016, A synthesis of the basal thermal state of the Greenland Ice Sheet, Journal of Geophysical Research, 121, 1328-1350, doi:10.1002/2015JF003803.
J. MacGregor, W. Colgan, M. Fahnestock, M. Morlighem, G. Catania, J. Paden, S. Gogineni, 2016, Holocene deceleration of the Greenland Ice Sheet, Science, 351(590), 590-593, doi:10.1126/science.aab1702.
J. MacGregor, M. Fahnestock, G. Catania, J. Paden, S. Gogenini, S. Young, S. Rybarski, A. Mabrey, B. Wagman, M. Morlighem, 2015, Radiostratigraphy and age structure of the Greenland Ice Sheet, Journal of Geophysical Research, 120, 212-241, doi:10.1002/2014JF003215.
G. Catania, C. Hulbe and H. Conway, 2010, Grounding line basal melt rates from radar-derived internal stratigraphy, Journal of Glaciology, 56(197), 545-554, doi:10.3189/002214310792447842.
G. Catania, T. Neumann, 2010, Persistent englacial drainage features in the Greenland Ice Sheet, Geophysical Research Letters, 37 (L02501), doi:10.1029/2009GL041108.
G. Catania, T. Neumann and S. Price, 2008, Characterizing englacial drainage in the ablation zone of the Greenland Ice Sheet, Journal of Glaciology, 54(187), 567-578, doi:10.3189/002214308786570854.
G. Catania, T. Scambos, H. Conway and C. Raymond, 2006, The sequential stagnation of Kamb Ice Stream, West Antarctica, Geophysical Research Letters, 22(L14502), doi:10.1029/2006GL026430.
G. Catania, H. Conway, C. Raymond and T. Scambos, 2006, Evidence for floatation or near-floatation in the mouth of Kamb Ice Stream, West Antarctica, Journal of Geophysical Research: Earth Surface, 111(F01005), doi:10.1029/2005JF000355.
G. Catania, H. Conway, C. Raymond and T. Scambos, 2005, Surface morphology and internal layer stratigraphy in the downstream end of Kamb Ice Stream, West Antarctica, Journal of Glaciology, 51(174), 423-431, doi:10.3189/172756505781829142.
G. Catania, H. Conway, A. Gades, C. Raymond and H. Engelhardt, 2003, Bed reflectivity beneath inactive ice streams in West Antarctica, Annals of Glaciology, 36, 287-291, doi:10.3189/172756403781816310.