Bathymetry in Petermann fjord from Operation IceBridge aerogravity ...

• Main Authors: Tinto, Kirsteen J., Bell, Robin E., Cochran, James R., Munchow, Andreas
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2015
• Subjects: Geophysics; FOS: Earth and related environmental sciences; Marine geophysics; Glaciers > Measurement; Fjords; Bathymetric maps; Greenland; Petermann Fjord; glacier; Petermann glacier
• Online Access: https://dx.doi.org/10.7916/d8-2dct-4293; https://academiccommons.columbia.edu/doi/10.7916/d8-2dct-4293

Petermann Glacier is a major glacier in northern Greenland, maintaining one of the few remaining floating ice tongues in Greenland. Monitoring programs, such as NASA’s Operation IceBridge have surveyed Petermann Glacier over several decades and have found it to be stable in terms of mass balance, velocity and grounding-line position. The future vulnerability of this large glacier to changing ocean temperatures and climate depends on the ocean–ice interactions beneath its floating tongue. These cannot currently be predicted due to a lack of knowledge of the bathymetry underneath the ice tongue. Here we use aerogravity data from Operation IceBridge, together with airborne radar and laser data and shipborne bathymetry-soundings to model the bathymetry beneath the Petermann ice tongue. We find a basement-cored inner sill at 540–610 m depth that results in a water cavity with minimum thickness of 400 m about 25 km from the grounding line. The sill is coincident with the location of the melt rate minimum. Seaward ...