Iceberg Production and Characteristics at the Termini of Tidewater Glaciers around the Prince of Wales Icefield, Ellesmere Island

• Main Author: Dalton, Abigail
• Format: Thesis
• Language: English
• Published: Université d'Ottawa / University of Ottawa 2017
• Subjects: Icebergs; Glacier Dynamics; Remote Sensing; Arctic; Ellesmere Island; Canadian Arctic Archipelago; Prince of Wales Icefield; Arctic Archipelago; Iceberg*; Sea ice; Tidewater
• Online Access: https://dx.doi.org/10.20381/ruor-21264; http://ruor.uottawa.ca/handle/10393/36992

Since the 1960s, warming air and sea surface temperatures have led to decreasing sea ice extent and longer periods of open water in the Canadian Arctic Archipelago (CAA). Recent and rapid changes have also been observed in the ice discharge patterns of glaciers in this region. For example, Trinity and Wykeham glaciers on the Prince of Wales Icefield (POW), SE Ellesmere Island, contributed ~62% of total ice discharge to the ocean from the Canadian Arctic Archipelago in 2016, compared to ~22% in 2000. Given these changes, an important question is whether there is a relationship between changing sea ice conditions (e.g., extent, freeze up dates, break up dates) and iceberg production from these glaciers. This study used synthetic aperture radar (Radarsat-1, 2 and ALOS PALSAR) and optical (Landsat-7 and 8) imagery to identify iceberg plume events and sea ice break-up/freeze-up dates between 1997 and 2015 for 40 tidewater glaciers around the POW. Results show a clear relationship between the presence of sea ice and the production of icebergs from glaciers, with most events occurring during the open water season and fewer when sea ice was present. While there have not been clear increasing trends of icebergs produced from all glaciers in the POW, Trinity and Wykeham glaciers show that increases in detected iceberg plumes coincide with increases in previously measured glacier velocity and significant terminus retreat. Comparison to ocean temperature, surface air temperature from NCEP/NCAR reanalysis and tidal data showed no clear relationship with increased calving events, however further research into all factors is recommended. It is likely that there are several factors contributing to the spatial and temporal variability of iceberg production from the POW.