The Aftermath of Petermann Glacier Calving Events (2008–2012): Ice Island Size Distributions and Meltwater Dispersal

Anna J. Crawford, Derek R. Mueller, Luc Desjardins, Paul G. Myers

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Three large calving events occurred at Petermann Glacier in northwest Greenland between 2008 and 2012 that generated ice islands (large tabular icebergs) that ranged from ~30 to 300 km2 in areal extent. Ice islands are known to deteriorate, via fracture and melt, during their drift through regional water bodies where they pose a potential risk to offshore resource extraction operations and disperse freshwater from the Greenland Ice Sheet. This study presents the first analysis of the deterioration occurring across the flux of ice islands that travel between Nares Strait and the North Atlantic after Petermann Glacier calving events. The evolution of Petermann ice island size distributions was evaluated, and the spatial dispersal of meltwater was quantified, through analyses that utilized the newly developed Canadian Ice Island Drift, Deterioration and Detection Database. Size-frequency distributions remained relatively consistent, both spatially and temporally, and were well fit by power law models with slopes of approximately À1.7. This suggested that fracture was an important process by which the Petermann ice islands deteriorated, regardless of elapsed time or distance from the glacier. Ice island meltwater fluxes into the Baffin Island and Labrador currents were not large enough to slow down the Atlantic Meridional Overturning Circulation by weakening deep-water convection in the Labrador Sea. However, augmented meltwater input was calculated within Petermann Fjord (2.0 mSv) and in the vicinity of grounding locations (0.4 mSv). Further research is necessary to better understand how this freshwater alters fjord circulation and influences the composition of local ocean waters. Plain Language Summary Three large tabular icebergs (“ice islands”) broke away from Petermann Glacier, northwest Greenland, between 2008 and 2012. We use the Canadian Ice Island Drift, Deterioration and Detection Database to investigate the ice island size distributions as well as how meltwater, generated through their drift and deterioration, is dispersed through water bodies such as Baffin Bay and the Labrador Sea. The size-frequency distributions were best fit by power law models, which suggests that fracture was an important process by which the Petermann ice islands deteriorated. While augmented meltwater input was calculated within Petermann Fjord and at grounding locations, ice island meltwater fluxes were not large enough to slow down the Atlantic Meridional Overturning Circulation. Our results contribute to the two dominant themes of ice island research: their role in the dispersal of freshwater from the major Arctic and Antarctic ice sheets and the risk that they pose to shipping and offshore resource extraction operations.
Original languageEnglish
Pages (from-to)8812-8827
JournalJournal of Geophysical Research: Oceans
Volume123
Issue number12
DOIs
Publication statusPublished - 1 Dec 2018

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