Late Weichselian and Holocene sedimentary environments and glacial activity in Billefjorden, Svalbard

Abstract

Swath bathymetry data and one sediment core were used to improve the understanding of the Late Weichselian and Holocene glacier activity in Billefjorden, Svalbard. Grounded ice existed in Billefjorden prior to 11.23 cal ka BP (calendar years before present), depositing a basal till and producing glacial lineations. The glacier front retreated from the central parts to the inner parts of the fjord between c. 11.23 and 11.2 cal ka BP. Annual recessional moraines suggest that this retreat occurred at a rate of up to 170 m a−1. During the early Holocene, the glacier Nordenskiöldbreen was comparatively small and sediment supply to central Billefjorden occurred mainly from the fjord sides. An increase in ice rafting around 7930 cal a BP is ascribed to enhanced sea-ice formation. The activity of Nordenskiöldbreen increased around 5470 cal a BP. Ice rafting was generally low during the past c. 3230 a. This was most likely related to the formation of a more permanent sea-ice cover. Nordenskiöldbreen reached its maximum Holocene extent around AD 1900, generating glacial lineations and depositing a terminal moraine in the inner fjord. Annual recessional moraines were formed during its subsequent retreat. Icebergs from Nordenskiöldbreen generated iceberg ploughmarks during the late Holocene.

Submarine landform assemblages and sedimentary processes related to glacier surging in Kongsfjorden, Svalbard

“…Deglaciation of the shelf and fjords on west Spitsbergen began around 20,500 AE 500 cal a BP and was interrupted by multiple glacier halts and/or re-advances (e.g. [3,31,32,43,46,65]). The deglaciation of Kongsfjorden proper was documented as a two-stage recession initiated $ 13,000 cal a BP, leading to ice-free conditions by approximately 9000 cal a BP [52].…”

“…[3,30,31,33]). Maximum Late Holocene glacier extents occurred either due to climatic cooling during the Little Ice Age or due to glacier surges (e.g.…”

“…Based on appearance and dimensions, the grooves and ridges are similar to (mega-scale) glacial lineations (MSGLs; e.g. [1,3,12,29,63,64,76]), which are closely associated with fast ice-flow [47]. Even though lineations in Kongsfjorden are much shorter (max.…”

“…[10,20,22,25,63,66,71,73]). Landforms related to glacier surges in submarine settings have been described from several Spitsbergen fjords [3,10,29,63,66,67]. The landform models suggested thus far include overridden recessional moraines, (mega-scale) glacial lineations, terminal moraines with associated sediment lobes on their distal slopes, eskers, annual push moraines and crevasse-squeeze ridges, the latter suggested to be the only feature diagnostic of a glacier surge [66,71].…”

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

“…Nordenskiöldbreen has been the subject of a number of glaciological (Den Ouden et al, 2010;Hagen, Eiken, Kohler, & Melvold, 2005;Rachlewicz et al, 2007;Van Pelt et al, 2012, 2014 and geomorphological (Boulton, 1970(Boulton, , 1976Kłysz, 1988;Kłysz, Lindner, Marks, & Wysokiński, 1989;Slater, 1925;Stacke, Mida, Lehejček, Tóthová, & Nývlt, 2013;Strzelecki, 2011) studies, including some geomorphological mapping (Karczewski et al, 1990;Kłysz et al, 1989) (Baeten, Forwick, Vogt, & Vorren, 2010;Plassen, Vorren, & Forwick, 2004;Szczuciński, Zajączkowski, & Scholten, 2009). However, most of the previous work concentrated on the northern margin, and so far no coherent map of glacial geomorphology has been produced for both terrestrial parts of the foreland and hence no comparison has been made between the landform signatures of these two clearly contrasting parts of the snout.…”