New fjords, new coasts, new landscapes: The geomorphology of paraglacial coasts formed after recent glacier retreat in Brepollen (Hornsund, southern Svalbard)

Abstract

Changes in the properties and dynamics of tidewater glacier systems are key indicators of the state of Arctic climate and environment. Calving of tidewater glacier fronts is currently the dominant form of ice mass loss and a major contributor to global sea‐level rise. An important yet under‐studied aspect of this process is transformation of Arctic landscapes, where new lands and coastal systems are revealed due to the recession of marine‐terminating ice masses. The evolution of those freshly exposed paraglacial coastal environments is controlled by nearshore marine, coastal and terrestrial geomorphic processes, which rework glacial‐derived sediments to create new coastal paraglacial landforms and landscapes. Here, we present the first study of the paraglacial coasts of Brepollen, one of the youngest bays of Svalbard revealed by ice retreat. We describe and classify coastal systems and the variety of landforms (deltas, cliffs, tidal flats, beaches) developed along the shores of Brepollen during the last 100 years. We further discuss the main modes of sediment supply to the coast in different parts of the new bay, highlighting the fast rate of coastal transformation as a paraglacial response to rapid deglaciation in the Arctic. This study provides an exemplar of likely coastal responses to be anticipated in similar tidewater settings under future climate change. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd

Multiple drivers of Late Holocene paraglacial sediment reworking in Ireland

“…4F) corresponds to infilling of this accommodation space by slope and aeolian sediments in an aggradational sequence. Similar coastal sand accumulations in sand dunes and estuary infills also reflect this paraglacial inheritance of high shelf sediment supply during the Holocene (Knight & Burningham 2014;Knight & Harrison 2018a;Knight & Strzelecki 2020).…”

“…However, it is now recognized that paraglacial sediment reworking is a common driver of lateglacial and postglacial geomorphic and sediment patterns in Ireland (Wilson 2017;Knight & Harrison 2018a), including in coastal areas where high glacigenic sediment availability has given rise to rapid postglacial coastal change by waves and sea-level change (e.g. Carter et al 1989;Greenwood & Orford 2008;Knight & Burningham 2014;Knight & Strzelecki 2020).…”

“…Paraglacial processes and environments are increasingly recognized as important elements of global coastlines that are responding to the effects of Late Pleistocene deglaciation or to present-day ice retreat in the Anthropocene (Knight & Harrison 2009a, b, 2014Knight & Strzelecki 2020;Strzelecki et al 2020). Forbes & Syvitski (1994: p. 376) define paraglacial coasts as 'those on or adjacent to formerly ice-covered terrain, where glacially excavated landforms or glaciogenic sediments have a recognizable influence on the character and evolution of the coast'.…”

Combined Use of Aerial Photogrammetry and Terrestrial Laser Scanning for Detecting Geomorphological Changes in Hornsund, Svalbard

“…The Hornsund area in southern Spitsbergen (Svalbard) is the focus of wide glaciological [1][2][3][4], hydrological [5][6][7][8][9], snow [9], permafrost [10,11], geomorphometric [12][13][14] and biological [15] studies performed due to intensive alterations in the surveyed terrain. Digital mapping of such an environment and its related phenomena has become a fundamental requirement to keep track of all such alterations [16].…”

Processes controlling the development of talus slopes in SW Spitsbergen: The role of deglaciation and periglacial conditions

“…Deglaciation exposes areas/terrains which are transformed by the operation of paraglacial processes. Paraglacial processes are described as nonglacial, but conditioned by glaciers (Church & Ryder, 1972) and examples can be found relating to paraglacial environments on Svalbard in, for example, works by Ewertowski and Tomczyk (2020) on ice-cored moraine formation and degradation, Owczarek, Nawrot, Migała, Malik, and Korabiewski (2014) on the evolution of rivers, Strzelecki et al (2018Strzelecki et al ( , 2020 on coastal systems. Examples are found in the talus slopes that are commonly found in glacial valleys in Svalbard, where they develop in interaction with glaciers and are influenced by paraglacial processes (Senderak, Kondracka, & Gądek, 2017).…”