Multidecadal Recession of Grinnell and Terra Nivea Ice Caps, Baffin Island, Canada

Abstract

ABSTRACT. Multi-temporal satellite imagery and historical aerial photography reveal that two southern Arctic ice caps on Baffin Island have shrunk considerably over the past several decades. Satellite remote sensing shows that over the past three decades, the Grinnell and Terra Nivea ice caps, the southernmost ice caps in the eastern Canadian Arctic, have decreased in area by 18% and 22% respectively, which corresponds to a total area decline of 68 km 2 since mapping done in the late 1950s. Cumulative ice loss since the mid-1970s has occurred at a rate of −1.69 km 2 /yr. The Grinnell ice cap has declined in area by −0.57 km 2 /yr, while the larger Terra Nivea ice cap has lost ice at a rate of −1.1 km 2 /yr. Interior thinning has led to the exposure of nunataks far from ice margins, and outlet glaciers have retreated substantial distances up-valley. The rapid reduction in ice area is linked directly to increasing summer air temperatures and suggests that these ice caps are in disequilibrium with recent climate conditions. Projections suggest that if the observed ice decline continues to AD 2100, the total area covered by ice at present will be reduced by more than 57%.Key words: glaciology; glacier change; climate; Grinnell and Terra Nivea ice caps; Baffin Island RÉSUMÉ. L'imagerie satellitaire multitemporelle et la photographie aérienne historique révèlent que deux calottes glaciaires du sud de l'Arctique, dans l'île de Baffin, ont rétréci considérablement au cours des dernières décennies. La télédétection par satellite montre qu'au cours des trois dernières décennies, l'étendue des calottes glaciaires Grinnell et Terra Nivea, soit les calottes glaciaires les plus au sud de l'Arctique canadien de l'est, a diminué dans une mesure de 18 % et de 22 % respectivement, ce qui correspond à un déclin total de l'étendue de 68 km 2 depuis que la cartographie a été effectuée vers la fin des années 1950. Depuis le milieu des années 1970, la perte cumulative de glace s'est produite au taux de −1,69 km 2 /an. L'étendue de la calotte glaciaire Grinnell a diminué de −0,57 km 2 /an, tandis que la calotte glaciaire Terra Nivea, dont l'étendue est plus grande, a enregistré une perte de glace de l'ordre de −1,1 km 2 /an. L'amincissement intérieur a donné lieu à l'exposition de nunataks loin des marges glaciaires, et les glaciers émissaires ont reculé sur d'importantes distances en amont de la vallée. La réduction rapide de l'étendue de la glace est directement liée à l'augmentation de la température de l'air d'été, ce qui suggère que ces calottes glaciaires sont en déséquilibre par rapport aux conditions climatiques récentes. Selon les projections, si la réduction observée de la glace se poursuit jusqu'en l'an 2100 A.D., l'étendue totale actuellement couverte par la glace diminuera de plus de 57 %.

Glacier change from the early Little Ice Age to 2005 in the Torngat Mountains, northern Labrador, Canada

“…The glaciers in the eastern Canadian Arctic and the North Atlantic sector are expected to be the closest analogues to Torngat glaciers owing to regional geographic and climatic similarities (Kottek et al, 2006). However, observed glacier changes in the Torngat Mountains greatly exceed those observed (7-37%) in the eastern Canadian Arctic (e.g., Dowdeswell et al, 2007;Paul and Kääb, 2005;Paul and Svoboda, 2009;Way, 2015;Wolken et al, 2008;Wolken, 2006), in west Greenland (~20%) (Citterio et al, 2009), and in Norway (35%) (Baumann et al, 2009). These differences likely reflect the characteristically smaller size of Torngat glaciers relative to the aforementioned regions, as very small glaciers (b 1 km 2 ) can demonstrate greater sensitivity to climatic changes (Granshaw and Fountain, 2006;Kuhn, 1995).…”

“…While historical glacier changes for the large glacier populations of the Canadian Arctic are comparatively well studied (e.g., AMAP, 2011;Dowdeswell et al, 2007;Mair et al, 2009;Paul and Svoboda, 2009;Sharp et al, 2014;Svoboda and Paul, 2009;Way, 2015), the lowArctic glaciers in the Torngat Mountains of northern Labrador have yet to be assessed for historical change on a regional scale . Several local studies conducted south of Nachvak Fiord (Fig.…”

Underestimated warming of northern Canada in the Berkeley Earth temperature product

“…Output climate products from BETP consist of monthly minimum, mean and maximum temperature grids which are publically available and updated on a bi‐annual basis. At the regional‐scale, the BETP product has been evaluated as a reliable representation of surface air temperatures in the Labrador‐Ungava region (Way and Viau, ), southern Baffin Island (Way, ), northern Australia (Trewin and Jones, ), the conterminous United States (Oyler et al , ) and Slovenia (Vertačnik et al , ). However, despite its widespread usage at various spatial scales, the BETP data set has not been systematically assessed at the national‐scale in any high latitude environments.…”

Remote sensing assessment of glacial loss and vegetation change from 1989 to 2016: Pond Inlet, Nunavut

“…Rising temperatures have resulted in a glacial surface warming of 0.8 to 2.2°C in the Arctic over the last decade (Sharp et al, 2011). This warming has increased glacial melt rates, which are currently at the highest point they have been in several millennia (Way, 2014). Pan-Arctic greening trends reveal ecosystems are increasing in plant matter (biomass) as higher temperatures allow more growth (Jia et al, 2003).…”