Research
Big Data in Glaciology
Terminus picks from glaciers around Greenland. Left shows the number of images available per glacier. Right shows the success rate in picking termini from each available image.
Using the enormous archive of existing satellite data we can produce unprecedented time series of glacier change. Making use of that data requires that we skillfully extract information (and uncertainties) from satellites and that we engage a broad set of tools for analysis. This is particularly challenging for Greenland, which has over 300 outlet glaciers.
Related 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 determine the controls on glacier termini using machine learning. 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.
Related Projects:
Submersibles in the icy deep - Exploring sediment-ice sheet interactions (funded by the W.M. Keck Foundation and the National Science Foundation)
Collaborating with Sean Gulick, John Goff, John Jaeger, Mike Jakuba, Molly Curran, Rebecca Jackson, Emily Eidam
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
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.
Glacier termini are ground zero for ice sheet change. This is where the atmosphere, ocean, ice sheet, and subglacial substrate all come together and interact. Such interaction creates multiple processes that influence terminus behavior on a range of time scales. Direct observations of terminus processes are challenged by remote, difficult, and hazardous conditions making remote sensing, or remote-operated vehicles an important part of an observational campaign.
Glacier Terminus Behavior
A first-order control on ice dynamics includes the ice sheet topography (bed and surface elevations and slope). Understanding the role that topography (or geometry) plays on ice dynamics allows us to disentangle the relative importance of climate-induced perturbations to ice dynamics from internal change. Further, because topography can change over time, particularly at the ice-bed where sedimentation and erosion rates are large, this is an area for active research into the pace and scale of topographic change.
Topographic Controls on Ice Dynamics
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.
Related 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
Related 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.
Related 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 reveals the processes that shape longer-term (centennial and greater) ice sheet change. This also allows glaciologists to put recent changes into context and to understand the pace and scale of natural versus climate-induced ice sheet change.
Ice Sheet History
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.