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Tides modulate crevasse opening prior to a major calving event at Bowdoin Glacier, Northwest Greenland
- Source :
- Journal of Glaciology, Vol 66, Pp 113-123 (2020)
- Publication Year :
- 2020
- Publisher :
- Cambridge University Press, 2020.
-
Abstract
- Retreat of calving glaciers worldwide has contributed substantially to sea-level rise in recent decades. Mass loss by calving contributes significantly to the uncertainty of sea-level rise projections. At Bowdoin Glacier, Northwest Greenland, most calving occurs by a few large events resulting from kilometre-scale fractures forming parallel to the calving front. High-resolution terrestrial radar interferometry data of such an event reveal that crevasse opening is fastest at low tide and accelerates during the final 36 h before calving. Using the ice flow model Elmer/Ice, we identify the crevasse water level as a key driver of modelled opening rates. Sea water-level variations in the range of local tidal amplitude (1 m) can reproduce observed opening rate fluctuations, provided crevasse water level is at least 4 m above the low-tide sea level. The accelerated opening rates within the final 36 h before calving can be modelled by additional meltwater input into the crevasse, enhanced ice cliff undercutting by submarine melt, ice damage increase due to tidal cyclic fatigue, crevasse deepening or a combination of these processes. Our results highlight the influence of surface meltwater and tides on crevasse opening leading to major calving events at grounded tidewater glaciers such as Bowdoin.
Details
- Language :
- English
- ISSN :
- 00221430 and 17275652
- Volume :
- 66
- Database :
- Directory of Open Access Journals
- Journal :
- Journal of Glaciology
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.9a9d6befa99b448ca3cb1fc7006645dd
- Document Type :
- article
- Full Text :
- https://doi.org/10.1017/jog.2019.89