BER launches Environmental System Science Program. Visit our new website under construction!

U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Leaky Plumbing Impedes Greenland Ice Sheet Flow
Published: December 19, 2016
Posted: May 10, 2017

Water draining from weakly connected underlying regions limits ice flow in late summer and beyond.

The Science
Surface meltwater that drains to the bed of the Greenland Ice Sheet each summer causes changes in ice flow that cannot be fully explained by prevailing theories. Application of a new model for extensive, sediment-choked subglacial “swamps” at the ice sheet bed found that slow leakage of water from those areas explains why the ice sheet’s movement slows down in late summer and winter.

The Impact
The new model extends the long-recognized complexity of terrestrial hydrology to the historically simplified understanding of hydrology beneath glaciers, adding a third component to the longstanding traditional conceptual model of subglacial hydrology.

Summary
To assess if changes in weakly connected, swampy areas of the bed that have been previously ignored can explain why the ice sheet slows down in late summer and winter, the researchers developed a new model for weakly connected subglacial drainage and coupled it to an existing subglacial drainage model that includes distributed and channelized flow. When applied to a well-studied field site in Greenland by forcing the enhanced model with measurements of meltwater input to the ice sheet, the model matches water pressure variations previously measured in different parts of the subglacial drainage system. Additionally, modeled ice speed shows the same seasonal pattern as the observations — the same water levels in the moulin that drains water to the bed result in slower ice speed later in the summer. This is because the weakly connected regions of the bed become better connected as the basal drainage system grows during summer, causing some of these high-pressure areas to leak stored water. Lower water pressure and less lubrication of the bed lead to slower ice motion.

Contacts (BER PM)
Dorothy Koch
Earth System Modeling Program
Dorothy.Koch@science.doe.gov

(PI Contact)
Matthew Hoffman
Los Alamos National Laboratory

Funding
The U.S. Department of Energy Office of Science, Biological and Environmental Research and Advanced Scientific Computational Research, as part of the SciDAC PISCEES project.

Publication
Hoffman, M., Andrews, L., Price, S., Catania, G. & et al. “Greenland subglacial drainage evolution regulated by weakly connected regions of the bed.” Nature Communications 7, 13903 (2016). [10.1038/ncomms13903]. (Reference link)

Related Links
Greenland Subglacial Drainage Evolution Regulated By Weakly Connected Regions Of The Bed

Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling

Division: SC-33.1 Earth and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]

Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]

Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]

Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.

Analysis [more...]

Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco
Objectives

  • All plant biomass is sourced from the carbon-fixing enzyme Rub [more...]

List all highlights (possible long download time)