Fluctuations of tidewater glaciers in Hornsund Fjord (Southern Svalbard) since the beginning of the 20th century

Abstract

Significant retreat of glaciers terminating in Hornsund Fjord (Southern Spits− bergen, Svalbard) has been observed during the 20 th century and in the first decade of the 21 st century. The objective of this paper is to present, as complete as possible, a record of front positions changes of 14 tidewater glaciers during this period and to distinguish the main factors influencing their fluctuations. Results are based on a GIS analysis of archival maps, field measurements, and aerial and satellite images. Accuracy was based on an as− sessment of seasonal fluctuations of a glacier's ice cliff position with respect to its mini− mum length in winter (November-December) and its maximum advance position in June or July. Morphometric features and the environmental setting of each glacier are also pre− sented. The total area of the glacier cover in Hornsund Fjord in the period of 1899-2010 diminished approximately 172 km 2 , with an average areal retreat rate of 1.6 km 2 a −1 . The recession rate increased from~1 km 2 a −1 in first decades of the 20 th century up to~3 km 2 a −1 in years 2001-2010. The latest period was more thoroughly studied using optical satellite images acquired almost every year. The importance of glacier morphology and hypso− metry, as well as fjord bathymetry and topography is analyzed. Large glacier systems with low slopes terminating in deeper waters are retreating faster than small steep glaciers ter− minating in shallower water. A relation between mean annual air temperature and aerial retreat rate of tidewater glaciers was found for long time scales. A sudden temperature in− crease, known as the early 20 th century warming in Svalbard, and an increase in tempera− tures during recent decades are well reflected in deglaciation rate. Influence of sea water temperatures on calving and retreat of glaciers was considered and is significant in short−time intervals of the last decade. Surge events are non−climatic factors which com− plicate the record. They are reflected in front advance or fast retreat due to a massive calv− ing depending on the relation between ice thickness and water depth. Despite the influ− ence of many factors, the response of tidewater glaciers to climate change is evident. The average linear retreat rate of all the tidewater glaciers in Hornsund amounted to~70 ma −1 in 2001-2010 and was higher than the average retreat of other Svalbard tidewater glaciers (~45 ma −1 ). Thus, glaciers of this basin can be considered as more sensitive to climate than glaciers of other regions of the archipelago.

Glacial geomorphology of the terrestrial margins of the tidewater glacier, Nordenskiöldbreen, Svalbard

“…They have retreated extensively since the end of the Little Ice Age (LIA; Rachlewicz, Szczuciński, & Ewertowski, 2007), in a manner similar to many other marine-and land-terminating glaciers on Svalbard (e.g. Błaszczyk, Jania, & Kolondra, 2013;Małecki, 2013;Mansell, Luckman, & Murray, 2012;Nuth, Kohler, Aas, Brandt, & Hagen, 2007;Nuth et al, 2013). De Geer (1910( , after Slater, 1925) reported a stationary ice margin of Nordenskiöldbreen between 1892 and 1896, located at the maximum historical limit, and a slight retreat (100-200 m) between 1896 and 1908.…”

Marine birds and mammals foraging in the rapidly deglaciating Arctic fjord - numbers, distribution and habitat preferences

“…Glacier melting in Hornsund fjord is proceeding rapidly (Błaszczyk et al 2013; Fig. 1), substantially changing the fjord's topography and the breeding/foraging-habitat used by marine birds and mammals.…”

Quantification of the ice-cored moraines' short-term dynamics in the high-Arctic glaciers Ebbabreen and Ragnarbreen, Petuniabukta, Svalbard

“…Quantitative studies of Svalbard glaciers, however, have concentrated mainly on transformations in glacier geometry, dynamics and mass balance (e.g. Hagen and Liestøl, 1990;Hagen et al, 1993;Jania and Hagen, 1996;Melvold and Hagen, 1998;Ziaja, 2001;Bamber et al, 2005;Ziaja, 2005;Nuth et al, 2007;Zagorski et al, 2008Zagorski et al, , 2012Sund et al, 2009;Moholdt et al, 2010a,b;Nuth et al, 2010;Kristensen and Benn, 2012;Mansell et al, 2012;Murray et al, 2012;Błaszczyk et al, 2013;Małecki, 2013). Quantification of changes in glacial landforms, including transformations due to dead-ice melting, has been made in a much smaller number of studies (e.g.…”