Bettina Schulz Paulsson explains the origin and spread of Europe's megaliths, including Stonehenge.
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Edited by Mark H. Thiemens, University of California, San Diego, La Jolla, CA, and approved May 8, 2014 (received for review March 19, 2014)
Significance
Thwaites Glacier is one of the West Antarctica's most prominent, rapidly evolving, and potentially unstable contributors to global sea level rise. Uncertainty in the amount and spatial pattern of geothermal flux and melting beneath this glacier is a major limitation in predicting its future behavior and sea level contribution. In this paper, a combination of radar sounding and subglacial water routing is used to show that large areas at the base of Thwaites Glacier are actively melting in response to geothermal flux consistent with rift-associated magma migration and volcanism. This supports the hypothesis that heterogeneous geothermal flux and local magmatic processes could be critical factors in determining the future behavior of the West Antarctic Ice Sheet.
Abstract
Heterogeneous hydrologic, lithologic, and geologic basal boundary conditions can exert strong control on the evolution, stability, and sea level contribution of marine ice sheets. Geothermal flux is one of the most dynamically critical ice sheet boundary conditions but is extremely difficult to constrain at the scale required to understand and predict the behavior of rapidly changing glaciers. This lack of observational constraint on geothermal flux is particularly problematic for the glacier catchments of the West Antarctic Ice Sheet within the low topography of the West Antarctic Rift System where geothermal fluxes are expected to be high, heterogeneous, and possibly transient. We use airborne radar sounding data with a subglacial water routing model to estimate the distribution of basal melting and geothermal flux beneath Thwaites Glacier, West Antarctica. We show that the Thwaites Glacier catchment has a minimum average geothermal flux of ∼114 ± 10 mW/m2 with areas of high flux exceeding 200 mW/m2 consistent with hypothesized rift-associated magmatic migration and volcanism. These areas of highest geothermal flux include the westernmost tributary of Thwaites Glacier adjacent to the subaerial Mount Takahe volcano and the upper reaches of the central tributary near the West Antarctic Ice Sheet Divide ice core drilling site.
Footnotes
- ↵1To whom correspondence should be addressed. E-mail: dustin.m.schroeder{at}utexas.edu.
Author contributions: D.M.S. designed research; D.M.S. performed research; D.M.S. contributed new reagents/analytic tools; D.M.S., D.D.B., D.A.Y., and E.Q. analyzed data; and D.M.S., D.D.B., D.A.Y., and E.Q. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
*Clow GD, Cuffey K, Waddington E, American Geophysical Union Fall Meeting, December 3–7, 2012, abstr C31A-0577.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1405184111/-/DCSupplemental.
Freely available online through the PNAS open access option.
Thwaites Glacier geothermal flux
Sign up for Article Alerts
Jump to section
You May Also be Interested in
Researchers are mining the stuff we excrete to get a window on drug use, antibiotic resistance, and the overall health of populations.
Image credit: Biobot Analytics.
For too long, the considerable importance and impacts of recreational fisheries have been ignored. Policymakers and managers need to do a better job acknowledging and addressing this very influential sector.
Image credit: Florian Möllers (photographer).
PNAS QnAs with NAS foreign associate and physicist Anne L’Huillier.
Image courtesy of Erika Weiland (photographer).
Brain metabolism scans in individuals aged 20–82 years revealed that compared with male brains, female brains appeared three to four years younger on average, suggesting potential links between sex and human brain aging.
Image courtesy of Pixabay/geralt.