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Episodic Subglacial Drainage Outbursts Below the Northeast Greenland Ice Stream
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  • Jonas Kvist Andersen,
  • Nicholas Mossor Rathmann,
  • Christine S. Hvidberg,
  • Aslak Grinsted,
  • Anders Kusk,
  • John Peter Merryman Boncori,
  • Jeremie Mouginot
Jonas Kvist Andersen
DTU Space, Technical University of Denmark

Corresponding Author:[email protected]

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Nicholas Mossor Rathmann
Niels Bohr Institute, University of Copenhagen
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Christine S. Hvidberg
Niels Bohr Institute, University of Copenhagen
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Aslak Grinsted
Niels Bohr Institute, University of Copenhagen
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Anders Kusk
DTU Space
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John Peter Merryman Boncori
DTU Space, Technical University of Denmark
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Jeremie Mouginot
Université Grenoble Alpes, CNRS
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Abstract

Subglacial hydrology can exert an important control on ice flow by affecting drag at the ice-bedrock interface. Here, we report on a series of subglacial drainage events (outbursts) along the Northeast Greenland Ice Stream (NEGIS), initiating as far inland as ~500 km from the margin of Zachariae Isstrøm. The drainage events are associated with local transient uplift, followed by prolonged subsidence, measured by satellite synthetic aperture radar interferometry (DInSAR). In downstream regions, drainage events are associated with a local speed-up in ice flow. The high spatiotemporal resolution of the DInSAR measurements allows for a detailed mapping of the drainage propagation pathway. We show that multiple drainage cascades have occurred along the same identified pathway over the years 2020-2022. Finally, the propagation speed of subglacial water flow is found to vary greatly along NEGIS, suggesting that fundamental differences may exist in the subglacial environment.
07 Mar 2023Submitted to ESS Open Archive
09 Mar 2023Published in ESS Open Archive