-With images-
A team of international scientists has unveiled a ground-breaking new map of the geological provinces hidden beneath the Greenland Ice Sheet.
This comprehensive synthesis, published in Geophysical Research Letters, promises to advance our understanding of this critical component of the global climate system.
This new subglacial geology map provides an invaluable modernised framework for interpreting the solid earth properties that shape the Greenland Ice Sheet's past, present, and future behaviour.
Using a new wealth of geophysical data, including seismic, gravity, magnetic, and topographic surveys, the researchers have meticulously delineated the boundaries of geological provinces across the island and – critically – beneath the ice.
This updated map represents a significant advancement over previous efforts, which were hampered by limited data available at the time. By combining diverse geophysical datasets, the researchers have been able to map Greenland’s subsurface structure in unprecedented detail, revealing a far more complex picture than was previously known.
Lead author of the study, Dr Joseph MacGregor from NASA's Goddard Space Flight Centre said: "This new map will help unlock a wealth of insights about Greenland's geological evolution and its interactions with the ice sheet.
"It will serve as an invaluable tool for researchers seeking to understand how the rocks beneath the ice sheet affect how it flows, which is crucial for improving projections of future sea level rise."
Notably, the team's findings show that north of 72°N, Greenland's geology is clearly more heterogeneous than previously thought.
There are also three distinct subglacial regions identified in central and northern Greenland whose unique geophysical signatures do not align with the island's marginal geology.
Study co-author Dr Guy Paxman of Durham University said: "These unresolved regions are a tantalising puzzle. Their distinct characteristics suggest the presence of as-yet-unknown geological provinces.
“They show that there is still more to learn about this hidden environment, which could have significant implications for understanding Greenland's glacial history and future response to climate change."
Further, the researchers detected intriguing geophysical anomalies aligned with the onset regions of the Petermann Glacier and the Northeast Greenland Ice Stream – two of Greenland's most dynamic outlet glaciers.
This discovery points to a potential link between subglacial geology and ice sheet dynamics, a relationship that warrants deeper investigation.
In addition to these findings, the team's analysis of surface topography data revealed an extensive network of remarkably long, straight, and parallel subglacial valleys crossing Greenland's interior.
These features, which remain poorly resolved in current topographic models, may hold clues about the island's tectonic history and could provide new avenues for investigating the ice sheet's past dynamics.
This study is a collaborative effort involving scientists from NASA, the Geological Survey of Denmark and Greenland, Durham University, Columbia University, the University at Buffalo, the Université du Québec à Montréal, the University of Alaska Fairbanks, the University of Florida, Dartmouth College, and Princeton University.
ENDS
Media Information
Dr Guy Paxman from Durham University is available for interview and can be contacted on guy.j.paxman@durham.ac.uk.
Alternatively, please contact Durham University Communications Office for interview requests on communications.team@durham.ac.uk or +44 (0)191 334 8623.
Source
‘Geologic provinces beneath the Greenland Ice Sheet constrained by geophysical data synthesis’, (2024), J. A. MacGregor et. al., Geophysical Research Letters, 51, e2023GL107357. https://doi.org/10.1029/2023GL107357
Map - https://doi.org/10.22008/FK2/BUQQ9C
Graphics
Associated images are available via the following link: https://www.dropbox.com/scl/fo/elgqn47dhyoenaof2yygr/AM2EGhVUXI67FXHjR5aTdXY?rlkey=3z1rk1wd4dnz68w25frn3e26e&dl=0
Credit: Jeremy Harbeck / NASA
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Journal
Geophysical Research Letters