Ongoing grounding line retreat and fracturation initiated at the Petermann Glacier ice shelf, Greenland after 2016
The Petermann ice shelf is one of the largest in Greenland, buttressing 4 % of the total ice sheet discharge, and is considered dynamically stable. In this study, we use differential synthetic aperture radar interferometry to reconstruct the grounding line migration between 1992 and 2021. Over the l...
| Main Authors: | , , , , , , , |
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| Format: | Text |
| Language: | English |
| Published: |
2022
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| Subjects: | |
| Online Access: | https://doi.org/10.5194/tc-2022-16 https://tc.copernicus.org/preprints/tc-2022-16/ |
| Summary: | The Petermann ice shelf is one of the largest in Greenland, buttressing 4 % of the total ice sheet discharge, and is considered dynamically stable. In this study, we use differential synthetic aperture radar interferometry to reconstruct the grounding line migration between 1992 and 2021. Over the last thirty years, we find that the grounding line of Petermann retreated 4 km, 7.5 km and 4.5 km in the western, central and eastern sectors, respectively. However, it is only since 2017 that the glacier has undergone a significant retreat in its central section, receding more than 5 km along a retrograde bed grounded 500 m below sea level. Simultaneously, two large fractures developed, splitting the ice shelf in three sections, with partially decoupled flow regime. The retreat followed the warming of the ocean waters by 0.4 °C in Nares Strait. As a result, the glacier sped up by 15 % in 2016–2018. While the central sector stabilized on a sill, the eastern flank is sitting on top of a down-slopping bed, which might accentuate the glacier retreat in the coming years. |
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