Calving of a Large Greenlandic Tidewater Glacier has Complex Links to Meltwater Plumes and Mélange
Détails
ID Serval
serval:BIB_624859866AE2
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Calving of a Large Greenlandic Tidewater Glacier has Complex Links to Meltwater Plumes and Mélange
Périodique
Journal of Geophysical Research: Earth Surface
ISSN
2169-9003
2169-9011
2169-9011
Statut éditorial
Publié
Date de publication
04/2021
Peer-reviewed
Oui
Volume
126
Numéro
4
Langue
anglais
Résumé
Calving and solid ice discharge into fjords account for approximately half of the annual net ice loss from the Greenland ice sheet, but these processes are rarely observed. To gain insights into the spatiotemporal nature of calving, we use a terrestrial radar interferometer to derive a 3-week record of 8,026 calving events from Sermeq Kujalleq (Store Glacier, West Greenland), including the transition between a mélange-filled and ice-free fjord. We show that calving rates double across this transition and that the interferometer record is in good agreement with volumetric estimates of calving losses from contemporaneous unmanned aerial vehicle surveys. We report significant variations in calving activity over time, which obfuscate any simple power-law relationship. While there is a statistically significant relationship between surface melt and the number of calving events, no such relationship exists between surface melt and the volume of these events. Similarly, we find a 70% increase in the number of calving events in the presence of visible meltwater plumes but only a 3% increase in calving volumes. While calving losses appear to have no clear single control, we find a bimodal distribution of iceberg sizes due to small blocks breaking off the subaerial part of the glacier front and large capsizing icebergs forming by full-thickness failure. Whereas previous work has hypothesized that tidewater glaciers can be grouped according to whether they calve predominantly by the former or latter mechanism, our observations indicate that calving here inherently comprises both and that the dominant process can change over relatively short periods.
Mots-clé
glacier calving, glacier dynamics, radar interferometry, tidewater glacier
Web of science
Site de l'éditeur
Open Access
Oui
Création de la notice
06/09/2022 10:30
Dernière modification de la notice
30/01/2024 14:28