Wintertime supraglacial lake drainage cascade triggers large-scale ice flow response in Greenland
Abstract Surface melt forces summertime ice-flow accelerations on glaciers and ice sheets. Here, we show that large meltwater-forced accelerations also occur during wintertime in Greenland. We document supraglacial lakes (SGLs) draining in cascades at unusually high elevation, causing an expansive f...
| Published in: | Geophysical Research Letters |
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| Main Authors: | , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2023
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| Subjects: | |
| Online Access: | https://orbit.dtu.dk/en/publications/80c71f7a-9b6b-450f-9da1-4c3cb1690b43 https://doi.org/10.1029/2022GL102251 https://backend.orbit.dtu.dk/ws/files/310771031/Geophysical_Research_Letters_2023_Maier_Wintertime_Supraglacial_Lake_Drainage_Cascade_Triggers_Large_Scale_Ice_Flow_1_.pdf |
| Summary: | Abstract Surface melt forces summertime ice-flow accelerations on glaciers and ice sheets. Here, we show that large meltwater-forced accelerations also occur during wintertime in Greenland. We document supraglacial lakes (SGLs) draining in cascades at unusually high elevation, causing an expansive flow acceleration over a ∼5200 km 2 region during winter. The three-component interferometric surface velocity field and decomposition modeling reveals the underlying flood propagation with unprecedented detail as it traveled over 160 km from the drainage site to the margin, providing novel constraints on subglacial water pathways, drainage morphology, and links with basal sliding. The triggering SGLs continuously grew over 40 years and suddenly released decades of stored meltwater, demonstrating surface melting can impact dynamics well beyond melt production. We show these events are likely common and thus their cumulative impact on dynamics should be further evaluated. |
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