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Ice Masses of the Eastern Canadian Arctic Archipelago 13 Ice Masses of the Eastern Canadian Arctic Archipelago 13 Wesley Van Wychen, Luke Copland, and David Burgess Abstract since *2000 these ice shelves have been undergoing The islands of the Canadian Arctic, known as the significant reductions in their area and volume, often Canadian Arctic Archipelago (CAA), contain the largest caused by episodic calving events that can produce ice area of glacierized terrain outside of the ice sheets of islands with diameters of 10 km or more. Once detached, Greenland and Antarctica. The ice masses are focused in these ice islands can drift within the waters of the CAA the eastern part of the CAA, and stretch from the ice and Arctic Ocean for years to decades and may pose a shelves of northernmost Ellesmere Island to glaciers in threat to Arctic shipping and offshore oil developments. the southernmost parts of Baffin Island, together with a few mountain glaciers in northern Labrador. The majority Keywords of glacier ice (roughly 70%) is contained within the large Glaciers Á Mass balance Á Glacier motion Á Glacier ice masses located on Baffin Island (Penny and Barnes Ice dynamics Á Canadian Arctic Archipelago Caps), Bylot Island (Bylot Island Ice Cap), Devon Island (Devon Ice Cap), Ellesmere Island (Prince of Wales Icefield, Manson Icefield, Sydkap Ice Cap, Agassiz Ice Cap, Northern Ellesmere Icefield) and Axel Heiberg 13.1 Physical Geography of Ice Masses Island (Steacie and Müller Ice Caps). The remaining ice is in the Canadian Arctic stored mainly in smaller ice caps and valley glaciers that skirt the coastline. The region’s major ice caps typically The islands of the eastern Canadian Arctic Archipelago have maximum elevations around 2000 m asl and (CAA) contain *150,000 km2 of glacierized terrain, rep- descend to sea level where outlet glaciers meet the ocean. resenting 28% of the worlds glacierized area outside of the Scientific studies of glaciers in the Canadian Arctic began ice sheets (Sharp et al. 2014) (Fig. 13.1). Approximately in earnest in the 1950s, with previous knowledge largely 107,000 km2 of the glacier area is located in the northern gleaned from historical materials and expedition reports. CAA, in the Queen Elizabeth Islands (QEI: Devon, Axel Systematic in situ surface mass balance measurements Heiberg and Ellesmere Islands), while the remaining ice is initiated in the late 1950s and continue to present day, located in the southern CAA, on Baffin Island providing one of the longest continuous records of glacier (*37,500 km2) and Bylot Island (*5000 km2). The mass balance within the Arctic. The Canadian Arctic also region’s major ice masses are classified either as “ice caps” contains some of the very few remaining northern (broad dome-like ice masses less than 50,000 km2 in area hemisphere ice shelves. Recent analysis indicates that that cover much of the underlying topography), or “ice- fields” (differentiated from ice caps by the presence of W. Van Wychen (&) bedrock nunataks that protrude through the ice in their Department of Geography and Environment Management, interior regions) (Copland 2013). The remaining *10% University of Waterloo, Waterloo, ON, Canada terrestrial ice cover in this region is composed of stagnant e-mail: [email protected] plateau ice caps in the QEI less than *1200 km2 in size, and Á W. Van Wychen L. Copland standalone Alpine cirque glaciers, many of which fringe the Department of Geography, Environment and Geomatics, fi University of Ottawa, Ottawa, ON, Canada coastlines of Baf n Bay, Nares Strait and the Arctic Ocean. Figures 13.2, 13.3, and 13.4 provide field photos of various D. Burgess Natural Resources Canada, 601 Booth Street, glacier features in the Canadian Arctic. Ottawa, ON K1A 0E8, Canada © Springer Nature Switzerland AG 2020 297 O. Slaymaker and N. Catto (eds.), Landscapes and Landforms of Eastern Canada, World Geomorphological Landscapes, https://doi.org/10.1007/978-3-030-35137-3_13 298 W. Van Wychen et al. Fig. 13.1 Overview of the major ice masses of the eastern Canadian Icefield; 5 = Sydkap Ice Cap; 6 = Steacie Ice Cap, 7 = Müller Ice Cap; 8 High Arctic (denoted by green shading). 1 = Northern Ellesmere = Devon Ice Cap; 9 = Bylot Island Ice Cap, 10 = Barnes Ice Cap; 11 = Icefield; 2 = Agassiz Ice Cap; 3 = Prince of Wales Icefield; 4 = Manson Penny Ice Cap; 12 = Coastal Glaciers and Ice Caps of Baffin Island To understand the distribution of glaciers within the source, with the Arctic Ocean a secondary source (Koerner CAA, it is necessary to understand the regional climatology 1979). As a consequence, the distribution of glaciers within of the Arctic Islands. Mean annual air temperatures within the region follows these climatic conditions, with glacierized the Canadian Arctic decrease as a function of latitude and terrain concentrated in high latitude, mountainous areas elevation, such that areas located at high elevations and more adjacent to moisture sources, such as along the east coast of northerly latitudes are colder than those located at low ele- Ellesmere Island and west coast of Axel Heiberg Island vations and latitudes (Sharp et al. 2014). In general, the (Sharp et al. 2014). The major exception to this distribution climate of the CAA is characterized by relatively short, cool is Barnes Ice Cap, which is located on a plateau in the summers followed by longer, colder winters, which provides interior of Baffin Island and is thought to exist as a remnant the climatic conditions necessary for glacier formation and of the Laurentide Ice Sheet Complex (Briner et al. 2009). survival. In terms of precipitation, there is a southeast to Topographically, the major ice masses of the CAA gen- northwest gradient across the Canadian Arctic Archipelago, erally rise to elevations of 1800–2000 m asl at their sum- with annual average precipitation of 420 mm in Iqaluit and mits, with their inland ice descending gradually to margins at 70 mm in Eureka, with most of the region receiving less 400–500 m asl, and their large outlet glaciers often reaching than 200 mm annually. Baffin Bay is the dominant moisture the ocean. Ice cap sectors flowing towards coastlines 13 Ice Masses of the Eastern Canadian Arctic Archipelago 299 Fig. 13.2 The snout of a glacier on southeastern Penny Ice Cap, July 2016. Photograph L. Copland Fig. 13.3 A land-terminating outlet glacier located on western Axel Heiberg Island, July 2015. Photograph L. Copland adjacent to the Baffin Bay moisture source tend to be thicker bed elevation profiles (3–4 km in width) along most tide- than their inland counterparts (Koerner 1979; Leuschen et al. water glaciers in the Canadian Arctic (https://nsidc.org/data/ 2017) and are drained primarily by large fast-flowing outlet icebridge). An example from these datasets, combined with glaciers which terminate at sea-level. Locations of maximum high resolution surface elevation data from the ArcticDEM, ice thickness (600–800 m) exist under the head of major reveals detailed surface (Fig. 13.5a) and glacier bed outlet glaciers, where the onset of channelization funnels ice (Fig. 13.5b) topography of the Agassiz Ice Cap, NE Elles- from high elevation accumulation areas to the ocean and has mere Island. eroded the subglacial topography (Dowdeswell et al. 2004). Longitudinal profiles extracted along Cañon Glacier The most recent ice thickness surveys conducted in 2014 highlight the contrasting geometry between the surface and under NASA’s Operation IceBridge program mapped the bed geometry, which is characteristic of many glaciers 300 W. Van Wychen et al. Fig. 13.4 Photo of the calving front of Trinity Glacier, Prince of Wales Icefield, August 2016. Photograph L. Copland across the CAA. The relatively smooth descent in surface (25–75 m y−1) near the equilibrium line altitude (ELA) with elevation of Cañon Glacier as it extends from >2000 m asl to velocities decreasing to stagnation in both an up-glacier and sea level along its 80 km length (Fig. 13.5c) contrasts with down-glacier direction from this point. This pattern also the ice-bed interface, which is controlled by the underlying generally holds true for the small tidewater terminating gla- bedrock and drops sharply to 300–400 m below sea-level for ciers of the southern CAA, where speeds of 40–100 m y−1 are the lowermost 50 km of the glacier (Fig. 13.5d). The fact common near the ELA with ice motion often decreasing to that many tidewater glaciers of the northern CAA are near stagnation both up-glacier and down-glacier from there grounded well below sea level for tens of kilometers inland (Van Wychen et al. 2015). On the other hand, velocities of from their termini make them susceptible to thinning and 30–90 m y−1 are commonly found near the ELA of large acceleration driven by changes in sea level and the pene- tidewater terminating glaciers of the QEI, with velocities tration of warm ocean water at their beds. This can result in increasing in a down-glacier direction typically to 100– enhanced subaqueous melting, floatation, and the likely 250 m y−1 at their terminus (Van Wychen et al. 2014). Of presence of highly deformable marine sediments (Burgess particular note are the Trinity and Wykeham Glaciers of Prince et al. 2005; Dowdeswell et al. 2004). Ongoing analysis of of Wales Icefield, which have recently attained flow speeds high resolution geophysical datasets from airborne and of >1200 m y−1 and >600 m y−1 respectively. These maxi- satellite measurements are critical for improving current mum velocities attained by both glaciers make them currently estimates of mass loss through iceberg calving, changing the fastest flowing glaciers in the Canadian Arctic (Fig. 13.6a). glacier dynamics, and the potential for catastrophic collapse The velocity structure of Belcher Glacier on Devon Ice of glaciers in response to measured and predicted climate Cap can be used as an example of the general patterns of ice and ocean warming (Van Wychen et al.
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