2018 Articles
Complex Basal Thermal Transition Near the Onset of Petermann Glacier, Greenland
The basal thermal regime of ice sheets exerts a strong control on ice‐sheet stability and the onset of rapidly streaming flow. However, the nature of this thermal transition where sliding initiates is largely unconstrained by geophysical observations. In the Greenland Ice Sheet, topographic troughs or elevated geothermal heat fluxes typically define the onset of outlet glaciers. In contrast, Petermann Glacier in Northern Greenland does not have any distinct bed troughs or localized geothermal heating associated with its onset, making it an ideal site to investigate the basal thermal state and examine its role in the onset of Petermann Glacier. Here we use radar bed reflectivity and an ice‐sheet thermomechanical model to examine the basal thermal regime beneath Petermann Glacier. Our results reveal a complex thermal transition near the onset of Petermann Glacier. As the bed shifts from largely frozen to largely thawed with increasing distances from the ice divide, our results show that this thermal transition happens through alternating bands of frozen and thawed bands. The complex thermal state across the onset region suggests that lateral meltwater injection and local meltwater production determine the location of Petermann Glacier. Given the lack of topographic pinning at the onset location, the upstream margin of Petermann is vulnerable to migrate depending on a combination of advective cooling and meltwater supply from the interior of the ice sheet.
Geographic Areas
Files
- Chu_et_al-2017-JGRES_PetermannRouting.pdf application/pdf 2.87 MB Download File
Also Published In
- Title
- Journal of Geophysical Research: Earth Surface
- DOI
- https://doi.org/10.1029/2017JF004561
More About This Work
- Academic Units
- Lamont-Doherty Earth Observatory
- Marine Geology and Geophysics
- Published Here
- June 12, 2018