Paraglacial transformation and ice‐dammed lake dynamics in a high Arctic glacier foreland, Gåsbreen, Svalbard

The structural change of the Svalbard landscape from glacially dominated to paraglacial, that has taken place since the termination of the Little Ice Age (ca. 1900) is expressed by the widespread retreat of glaciers and progressive exposure of glacial landforms. This study provides insights into the rate of post‐LIA deglaciation and associated paraglacial transformation in the foreland of Gåsbreen, one of the first ever investigated glacier systems in the Arctic. Glacier is situated in Sørkapp Land (Southern Spitsbergen), a region characterized by one of the fastest deglaciation rates in the entire Svalbard Archipelago. During the investigated period, 1938–2020, the Gåsbreen was in a recession that accelerated after 1990, leading to its foreland increasing from 2.2 to 5.8 km2. The dynamics of landscape change in the glacier foreland, exposed since the end of LIA, manifested in i.e. the formation of ice‐dammed lakes, degradation in the surface of ice‐cored moraines and the landforms that are underlain by dead‐ice. Mass movements and debris flow on ice‐cored moraines and fluvioglacial processes had a great influence on this transformation. Enhanced proglacial runoff intensified denudation, transport and accumulation of sediments, which resulted, in: an increase in the extent of sandurs and proglacial riverbeds, an increase in the area of glacial lakes, extending and changing of the course of rivers in the glacier foreland. At the same time, the major lake system in the area—Goësvatnet underwent several cycles of filling and draining, often through glacial outburst flooding events.


| INTRODUCTION
The last few decades of sustained warming of the Arctic region are predominantly reflected in a strong surface air temperature rise and extensive decline of the sea-ice cover (e.g., Barry, 2017;Sumata et al., 2022;Thoman et al., 2020). Warming of the Arctic climate entailed also changes in terrestrial environments such as an increase of ground temperatures and degradation of permafrost (e.g., Dobi nski & Karjalainen et al., 2020;Smith et al., 2022), and/or rapid retreat of glaciers (e.g., Cook et al., 2019;Hugonnet et al., 2021;Małecki, 2022;Sasgen et al., 2022). Among subregions of the Arctic, exceptional climate warming was characteristic of the Barents Sea region with Svalbard Archipelago at its heart (Isaksen et al., 2022). Svalbard Archipelago experienced one of the fastest glacier mass loss since the termination of the Little Ice Age (LIA;1250-1900Geyman et al., 2022) and serves as a unique area to study the response of cold region landscapes to paraglacial transformation. Paraglaciation is a geomorphological concept describing the evolution of landscape after deglaciation. When glacial sediments and landforms are eroded and transported through a diverse range of sediment cascades to be accumulated or reworked into new, non-glacial landforms and landsystems (e.g., Ballantyne, 2002;Church & Ryder, 1972;Evans, 2005;Mercier, 2008;Strzelecki et al., 2018). In Svalbard paraglacial processes are currently most active on glacier forelands often characterized by ridges of moraines developed by the LIA glacier advance. The most common mechanisms observed along glacier margins are gravitational mass movements, dead ice degradation and associated collapse of landforms, debris slides, erosion, and transport of sediments by meltwater streams (e.g., Evans et al., 2012;Evans et al., 2022;M. W. Ewertowski & Tomczyk, 2020;Lønne & Lyså, 2005;Lukas et al., 2005;Lyså & Lønne, 2001;Schomacker & Kjaer, 2008;Tonkin et al., 2016). Another component of paraglacial landscape that started to frequently emerge in front of retreating glaciers are glacial lakes often dammed by moraines or glacier tongues (Urba nski, 2022;Wieczorek et al., 2023;Wołoszyn et al., 2022). In sites where marine-terminating glaciers rapidly exposes new bays and fjord shores a diverse of coastal landscapes evolve (Kavan & Strzelecki, 2023;Strzelecki et al., 2020).
Here we present the multidecadal paraglacial transformation of the Gåsbreen proglacial zone, likely the earliest mapped (1899 CE) and investigated glacier in Svalbard (De Geer, 1923). Using this unique study site, we describe and quantify landscape changes controlled by paraglacial processes operating in the glacier foreland with fluctuating glacial lake system, through the outwash plain down to the fjord coast. We define "proglacial zone" as the environment located in front of a glacier including the ice-marginal area and glacier foreland following the definition by Slaymaker (2009). 2 | STUDY AREA Svalbard Archipelago, situated between the Arctic Ocean, Greenland Sea and Barents Sea, is currently the fastest warming part of the Arctic region (Isaksen et al., 2022). Although the archipelago features an Arctic climate, due to the warm West Spitsbergen Current that passes along the western coast of its major island-Spitsbergen, experiences significantly higher temperatures than other areas at the same latitude (Eckerstorfer & Christiansen, 2011;Gjelten et al., 2016;Hanssen-Bauer et al., 2019). According to Nuth et al., 2013, ca. 57% (i.e., about 34,000 km 2 ) of Svalbard is covered by glaciers. The rest of the land is controlled by the presence of permafrost, which is present in ice free terrain in a continuous form in deglaciated mountain ranges and valleys (Gilbert et al., 2018;Humlum et al., 2003). The coastal permafrost is strongly controlled by sea water intrusion and exposure to wave impacts disturbing its shape and spatial distribution along the shores (Dobi nski & Kasprzak, 2020;Kasprzak et al., 2017).
Among other sectors of Svalbard-Sørkapp Land-the southernmost peninsula of Spitsbergen-is characterized by one of the sharpest climatic differentiation linked with influences of cold East Spitsbergen Current that flows along the eastern coast and warm West Spitsbergen Current on the opposite coast (Ziaja & Ostafin, 2014). Currently, the peninsula is connected to the rest of Spitsbergen Island by the ice bridge formed by two marineterminating glaciers-Hornbreen and Hambergbreen. However, with continuous rates of glacier recession, this ice bridge will fall in the coming decades opening an isthmus between Hambergbukta and Hornsund (Grabiec et al., 2018;Kavan & Strzelecki, 2023;Strzelecki et al., 2020).
For our study we selected the westernmost land-based glacier of Sørkapp Land-Gåsbreen, reaching a length of over 7 km (including the firn field). Surrounded by the high mountain ranges of southern Spitsbergen, it is fed from the northeast by the Bastionbreen and Garwoodbren tributary glaciers resting on the slopes of the Hornsundtind massif (1431 m a.s.l.). Its accumulation zone reaches a height of over 800 m a.s.l. extending partially on the slopes of the Mehesten massif, and glacial snout flows latitudinally from east to west, squeezing between the Silesiafjellet and Nordfallet massifs in the north and Midifjellet in the south (Figure 1).
The bedrock of the area is built of several geological formations.
In the eastern and central parts, the metamorphic series of the Heckla Hoek Formation with mica schists, quartzites, limestones, and dolomites of the older Paleozoic dominate. Whereas, in the western part of the area, the finer material of Proterozoic rocks from the Wurmbrandegga and Kovalavskajafjellet mountain ranges (green shales, phyllites, and gray phyllite limestones) prevails (Dallmann, 2014;Szupryczy nski, 1963).

| MATERIALS AND METHODS
The basis for the spatial analyzes and delimitation of glacial landforms consisted primarily of remote sensing data (aerial photos captured during the photogrammetric overflights commissioned by the Norwegian Polar Institute, Norsk Polarinstitutt, hereinafter referred to as NPI, satellite images, and digital elevation models (DEM) supplemented by topographic maps and pictures from fieldwork campaigns and literature review of archival maps, field reports, and academic papers.

| Archival data
The first scientific observations of the Gåsbreen glacier and its surroundings were carried out by the Russian expedition wintering on Spitsbergen in 1899/1900. During the expedition, Lake Goësvatnet and the frontal moraines of the Gåsbreen glacier were described and presented on a map at a scale of 1:50,000 (De Geer, 1923). Nearly four decades later, in 1938, during a German expedition operating in the same area headed by H. Rieche, another detailed map of the glacier was made at the scale of 1:25,000 (Pillewizer, 1939). One of the aims of the expedition was to investigate the movement of the Gåsbreen glacier, which was measured in several transverse profiles using the method of repeated terrophotogrammetric images (time parallax) (J. Jania, 1988;Pillewizer, 1939). Moreover, the Germans made a bathymetric plan of Lake Goësvatnet, establishing its depth at the glacier cliff at 59 m and stated that it is an ice-dammed lake from which the water outflow periodically onto the outwash plain of the glacier (Rieche, 1970).
Research activities in the foreland of the Gåsbreen continued in 1959 when two members of the Polish Expedition to Spitsbergen conducted research in the western and northern parts of the area. J. Szupryczy nski detailed the relief of the Gåsbreen marginal zone, focusing his observations on the forms associated with the direct accumulation of the glacier and its meltwater (Szupryczy nski, 1960). In the same season, S. Jewtuchowicz conducted studies of the forms of fluvioglacial accumulation-sanders, kames, and eskers (Jewtuchowicz, 1962;Jewtuchowicz, 1965;Szupryczy nski, 1965). After this first season, fruitful for Polish polar explorers, there was a break of several years in research on the peninsula.  Jania, 1979;J. Jania, 1982;J. A. Jania et al., 1981), the morphology and dynamics of glaciers of western Sørkapp Land, including changes in the extent of the Gåsbreen glacier (J. Jania, 1988;Ziaja, 1999), as well as maps of the surrounding mountain ranges (Kolondra, 1979;Kolondra, 1980). Some of these works were part of a wider research program aimed at the implementation of a synthetic cartographic study of the surroundings of the Hornsund fjord-a geomorphological map (J. A. Jania & Szczypek, 1987) and a topographic map at a scale of 1:25,000-which covered the Gåsbreen glacier along with its foreland (Barna & Warchoł, 1987).  & Schöner, 1996;W. Schöner & Schöner, 1997).

| Image data
The image data used in the study show the changes taking place in the glacier foreland since the 1930s. The data for the 1930s constituted oblique photos from the first photogrammetric overflight on Svalbard by the NPI in 1936 (Luncke, 1936) complemented by the photo from the terrestrial photogrammetric campaign carried out in 1938 by the Germans (Pillewizer, 1939). The data for the 1960s and  (Porter et al., 2018). The most recent image data consisted of six multispectral images at a resolution of 3 m acquired in the summer of 2020 by SkySat satellites launched by Planet Labs PBC (2020).

| Maps
A map for 1938 was produced at a scale of 1:25,000 based on terrestrial photogrammetric measurements carried out by W. Pillewizer during a German summer expedition (Pillewizer, 1939). The map was coregistered using a map grid at a 2 km interval. Subsequently, its coordinates were transformed to ETRS-89 datum in UTM projection (Zone 33X) based on a trigonometric network and the position of the mountain tops (Ziaja et al., 2016). Watercourses, water bodies, glacier boundaries, and contour lines of a 20 m vertical interval were digitized and used throughout the study.
A map representing the years 1960/1961 used in this study consisted of one sheet (08-Gåsbreen) at a scale of 1:25,000 made in a UTM projection based on a European Datum 1950 (ED50) ellipsoid published by the Polish Academy of Sciences (Polska Akademia Nauk, hereinafter referred to as PAS) (Barna & Warchoł, 1987). The processing of the map consisted of several stages. After initial rectification based on the nodes of the cartographic grid, the map coordinate system was converted, adopting the UTM projection (northern hemisphere, zone 33) in the ETRS-89 reference system. Thematic layers of the map-contours, elevation points, rivers, and lakes-were digitized, and subsequently, after finding their shifts in relation to the data from 2010, they were registered based on triangulation and topographic points. This allowed for cartographic compilation and integration of vector layers from the 1960s with data from other years (Dudek & Pętlicki, 2021).
The topographic map at a scale of 1:100,000 for 1990 and 2010 was developed and made available by NPI in the form of vector layers, in the ESRI shapefile format. In the study, we used layers presenting the general image of the area's surface: relief, permanent watercourses, water bodies, and elevation points. Glacier boundary for 1990 was established based on a field campaign and published by M. Schöner and Schöner (1996). The glacier boundary for 2010 was established based on aerial photos and digital elevation models.

| Digital elevation models
The DEM for the 1960s was constructed from shapefiles derived from the map edited by the PAS (Barna & Warchoł, 1987). Elevation points, streams, and contour lines at a 10 m vertical interval were converted to a 5 m Â 5 m regular grid. Created DEM was validated against the pre-existing 2010 elevation dataset of the NPI which was used as a reference dataset throughout the study (NPI, 2014). The average elevation difference between the 1990 and 1960 DEMs on ice-free areas with slopes inclined less than 20 was 2.28 m with a standard deviation of 3.18 m (Dudek & Pętlicki, 2021).
For the years 1990 and 2010, digital elevation models with a resolution of 20 m and 5 m respectively, made available by the NPI, were used. DEMs were generated using photogrammetric methods based on stereopairs correlation. The vertical accuracy of the DEMs given by the author was 2-5 meters in non-glacial areas and slightly less for glacier surfaces (NPI 2014).
The most recent elevation data used in the study was from July and August of 2020 and consisted of three stripes of ArcticDEM at a resolution of 2 m covering Gåsbreen and its vicinity.

| Geomorphological mapping
In order to quantify changes in proglacial areas a geomorphological mapping was carried out based on orthoimages, maps, DEMs, and observations from the field following previous mapping campaigns carried out on Svalbard glacier forelands (e. g. Allaart et al., 2018;Allaart et al., 2021;Arad ottir et al., 2019, Eckerstorfer et al., 2015Evans et al., 2012;M. W. Ewertowski et al., 2016;Farnsworth et al., 2016Farnsworth et al., , 2017Rubensdotter et al., 2015). The following three groups of depositional and erosional forms with respect to their origin were delimited in the proglacial zone of the glacier: • Forms and sediments of glacial provenience (i.e., terminal moraines frontal and lateral, hummocky moraines, ground moraines, crevasse fillings).
Geomorphological maps were created for the years 1936, 1961, 1990, 2010, and 2020. This allowed to determine the rates of proglacial and ice-marginal terrain change following deglaciation.

| Glacier retreat
During the 82 years of the study, Gåsbreen was in recession, as reflected in a decrease in its extent by 27%, from 14.7 km 2 in 1938 to 10.9 km 2 in 2020 (Table 1) Throughout that first period, the glacier was functioning as the natural dam for the Goësvatnet.
After 1990 recession of Gåsbreen continued to progress, which was accompanied by a significant change in the course of this process, with significant shortening of the glacial tongue and less intense lowering of its surface than in the previous period (Figures 2 and 3). in the 20th century. Initially, they consisted of single ice-cored moraines in front of glaciers termini. As the glaciers' fronts retreated, its forelands developed covering an increasingly larger area, and transformed into complexes of various landforms. In the period 1938-2020, the area of Gåsbreen's foreland increased from 2.2 km 2 to 5.8 km 2 (Figure 4). Within its limits, both depositional and erosional landforms were created (Figures 5 and 6).
The formation of depositional landforms is most often associated with the disappearance of the lower parts of the glaciers, which is why they occur mainly at the fronts and around the glaciers' snouts.
The most prominent depositional landforms in the foreland of T A B L E 1 Changes in Gåsbreen surface area and length over the period from 1938 to 2020. Research period 1938-1960 1960-1990 1990-2010 2010-2013 2013-2020 1938-2020 Glacier area change [km 2 (%)] Gåsbreen are frontal and lateral moraines with an ice core that constitutes up to 90% of their volume (Hagen et al., 2003),  the largest, was the main dam for the described lake, at the same time classifying it as an ice-blocked lake, and successively (subclass) as an advancing glacier blocked lake (Yao et al., 2018). The next two glaciers as mentioned before were the main source of water for Goësvatnet.
Based on our analysis based on de Geer's (1923) map of the Gåsbreen proglacial zone, the largest documented extent, Goësvatnet was 1.2 km 2 in 1899 (W. Schöner & Schöner, 1997). Since then (as systematically depicted in Figure 5), the lake has decreased in area, evolving with the retreating Gåsbreen, so that it did not refill its lake basin in 2004 due to a destroyed subglacial channel.
By analyzing the lake's extent on specific dates, it was possible to follow the trends associated with the evolution of Goësvatnet, which was characterized by a dynamic, seasonal variation in area. At the beginning of the summer season (i.e., June), the lake basin was freed from under the ice and gradually accumulated water from melting glaciers as well as from the surrounding peaks. It reached its maximum extent in a given year systematically at the turn of July and August (Figures 9 and 10). The years, for which we obtained a systematic range of data showing landscape changes over the whole summer season (with intervals of several days or more), indicate annual drainages of the lake just after reaching its maximum for a given season.
These runoffs, due to the amount of accumulated water and their duration, had the character of glacial lake outburst flooding (GLOF).
After each runoff, the lake did not refill again for the season.
The first and biggest documented runoff occurred between 1938 and 1956 and reduced the lake by 0.93 km 2 , 0.35 km 3 (Table 2). Further runoff occurred in 1961 and 1978. Since the 1970s, the accuracy of the analysis of glacial lake changes has been narrowed to specific days through the use of satellite data. Thus, it has been possible to document eight GLOFs consecutively (Figure 9). While the drainage of the lake in the 20th century was by means of a subglacial tunnel, under Gåsbreen, in the 21st century the tunnel was destroyed and the last drainage of the lake took place through a channel separating the Gåsbreen tongue from the dead ice, leading to the eventual disappearance of Goësvatnet (Ziaja & Ostafin, 2007).
The Goësvatnet runoff contributed to the modeling of the proglacial zone by creating new depressions, later used by the end-moraine dammed lakes, as well as shifting the course of the proglacial river channel, which, as a result of these sudden runoffs, had the character of an anastomosing river (Rosgen, 1994).
In 1938 surface area of Goësvatnet was approximately 0.93 km 2 ( Figures 5 and 11). In the 1960s, with the recession of Gåsbreen, endmoraine dammed lakes were created with a total area of 0.06 km 2 , which together with the developed Goësvatnet (0.62 km 2 ) totaled ( Figure 11). This shows that over the five decades the river network in the Gåsbreen foreland has increased by about 19 km. However, it should be noted that for the year 2020 we do not have as highresolution data as for previous periods, which makes this result subject to a certain margin of error. So, if we assume that 2013 is the year with better resolution scenes, and is more authoritative in terms of river network changes since the 1930s, the increase is ca. 29 km.
Since the 1930s, the density of watercourses in the study area has also changed ( Figure 11). In 1938 and 1961, the highest concentration of rivers was at the mouth of the bay and between the head of Gåsbreen and the moraine dike (Figure 5a). In 1990, the density of watercourses changed markedly-with a significant reduction in the area of Goësvatnet-with most watercourses located in the proglacial zone and in the area that was once occupied by the aforementioned lake ( Figure 5b). In 2010, where Gåsbreen is significantly regressing from previous decades, the highest density of watercourses is in front of the moraine in the area where the former subglacial tunnel that drained Goësvatnet had its outlet and in the area that was once occupied by the lake (Figure 5c). A similar trend (up to 2010) of river course densities continued until 2020 ( Figure 11).

| DISCUSSION
The warming of the Arctic climate entails changes in the glacial systems which are being translated into the dynamics of the entire polar environment. The course of the Gåsbreen recession was different than other land terminating glaciers of western Spitsbergen. Due to its specific terrain settings and the existence of a mountain barrier limiting the advance of the glacier and causing its pilling up on the slopes, Gåsbreen's frontal retreat rate before the 1990s, was relatively small in comparison with glaciers situated on the Wedel-Jarlsberg Land (Janina et al., 1984;Reder, 1996;Rodzik et al., 2013), in the central part of Spitsbergen (M. W. Ewertowski et al., 2019;Holmlund, 2021;Kavan, 2020;Małecki, 2016;Rachlewicz et al., 2007), in Kaffiøyra (Sobota & Lankauf, 2010) or further north in the vicinity of Ny-Ålesund . Following climate trends as recorded in meteorological stations across Spitsbergen an acceleration in the retreat rate of Gåsbreen was measured since the 1990s, which is consistent with similar recession styles observed for other land terminating glaciers in the region of western Sørkapp Land as well as further north of Spitsbergen (Dudek & Pętlicki, 2021;Kohler et al., 2007). Previous studies of the degradation of end moraines in Svalbard were rather sparse, which limits the possibility of comparing the size of this process within the archipelago (Bennett et al., 2000;Lukas et al., 2005;Ziaja & Pipała, 2007). Only a few areas in the north and north-west of Spitsbergen (Midgley et al., 2018;Schomacker, 2007;Schomacker & Kjaer, 2008;Tonkin et al., 2016) and in its central part (M. Ewertowski, 2014) were measured for at least one decade.

Retreat of glaciers in
The results from the proglacial zones of the glaciers in the northern Spitsbergen-Holmströmbreen (Schomacker & Kjaer, 2008) and Austre Lovénbreen (Tonkin et al., 2016)-mostly corresponded to the obtained results of the degradation rate of terminal moraines on the Sørkapp Land peninsula. On the other hand, in the foreland of the Ragnarbreen glaciers (M. Ewertowski, 2014) and Midtre Lovénbreen (Midgley et al., 2018), in recent decades the average dynamics of elevation changes was much lower than on Sørkapp Land. This proves that non-climatic factors, such as topography conditioning mass movements and debris flows, exposing relict ice to solar radiation, as well as fluvial erosion, may be of great importance for the transformation of end-moraines (Lukas et al., 2005;Schomacker, 2008). The results of recent short-term ( The progressive glacier recession leads to the exposure of the surface of subglacial forms and sediments or mutonised rocks of the substrate. In most of the Gåsbreen proglacial zone, there is still dead ice under the glacier deposits. Its slow melting is the cause of the continuous transformation of the relief and lowering its absolute and relative altitude (Ziaja et al., 2011). Where the ice has melted, the rate of evolution of landforms clearly slows down, which leads-at least in some places-to their stabilization and consolidation. The melting of dead ice was fostered by the impact of flowing and stagnant meltwater, which led to the formation of kettle holes and debris flows (Ziaja et al., 2011).
One of the elements of paraglacial landscape developing in front of retreating Gåsbreen is the network of seasonally disappearing glacial lakes. The lakes in the foreland of Gåsbreen are an example of glacial lake evolution, which additionally has numerous GLOF events in its history. The evolution of Goësvatnet, the major glacial lake formed in the area, shows how the development of ice-dammed lakes can proceed, which through its seasonal fluctuations has led to the formation of numerous end-dammed moraine lakes (Shukla et al., 2018). Due to its location, away from human settlements, Goësvatnet has never posed a real threat to humans. Ice-dammed lakes are among the most dynamic glacial lakes in the world, which also pose the greatest threat of glacial flooding (Bhambri et al., 2020;Prakash & Nagarajan, 2018;Shugar et al., 2020). Goësvatnet is not only indeed characterized by seasonal changes, which have been elaborated thanks to the availability of satellite images, but additionally, it inscribes a trend related to reaching the maximum of its extent in July/August and then creating a sudden drainage in the form of GLOF. Glacial flooding was observed at this location prior to the era of satellite imagery and it is evidenced by the numerous works of polar explorers who spends the summer season on the foreland of Gåsbreen, documented sudden, often single-day runoffs (Grze s & Banach, 1984;W. Schöner & Schöner, 1997;Ziaja et al., 2016). The mechanism of lake drainage itself was not fully understood from the outset. Seasonal runoff was accompanied by theories related to ice uplift due to the attainment of a sufficient height of the dammed lake surface (taking into account the buoyancy force) and the one that proved to be the final explanation-the formation of a subglacial channel due to summer ablation of the glacier and its refreezing in the winter season (Grze s & Banach, 1984). The number of papers describing the fluctuations of Goësvatnet may indicate that it is the best documented glacial lake in the entire Arctic, dating back to 1899 (Ziaja et al., 2016). With the data from the DEMs used, we were able to estimate the volume of water present in the lake before the individual GLOF events. We related these results directly to those presented by M. Schöner and Schöner (1996). It turned out that our estimated values were different from those presented in the indicated publication. This is clearly affected by the measurement error at the level of the DEM used (10 m resolution). Nevertheless, it indicates how large the scale of the GLOF events we have listed was. It is also important that we have added information to the current state of knowledge about the difference in the volume of the glacial lake from 1990 before and after the glacial flood, as well as from 2002 when it was last observed. Lakes formed after the final disappearance of Goësvatnet in the Gåsbreen foreland undoubtedly also arose from Goësvatnet runoff, especially the importance of the end-moraine dammed lakes, which today constitute the largest water bodies in the Gåsbreen foreland, must be emphasized here. Moraine-dammed lakes constitute the vast majority throughout Svalbard, which is related to the geological structure of western Spitsbergen (sedimentary rocks) and geomorphological conditions resulting from glacial activity (Małecki, 2016;Sobota et al., 2016). Due to the fact that moraine dams are made of unconsolidated material and also have dead ice inside, they are also characterized by low stability and sometimes seasonal changes in extent, as is the case with lakes in the rence of GLOF in these years (Kavan et al., 2022). Numerous glacial lake runoffs have also led to a strong remodeling of the Gåsbreen proglacial zone, as indicated by numerous (often only periodically waterfilled) river channels. The layout of these riverbeds indicates a model example of an anastomosing river (Rosgen, 1994), which, however, due to the length of runoff, is unable to develop the large forms associated with this river type. The aforementioned river type is indicative of the large amount of sediment that is carried by it and with a periodically flooded runoff zone (Teisseyre, 1984;Teisseyre, 1991).
6 | CONCLUSIONS 1. Over a century since the termination of the Little Ice Age Gåsbreen experienced constant recession and decrease in thickness, which significantly increased after 1990. The pace of rapid retreat was maintained in the 21st century and to a large degree modified by local topographic conditions.
2. The area of the Gåsbreens' foreland doubled in size due to glacier recession and is characterized by a highly dynamic landscape transformation. The key process observed in those freshly developing paraglacial areas is the degradation and lowering of frontal moraine ridges and other dead-ice landforms through mass movements and glaciofluvial action.
3. Decay of Gåsbreen exposed not only numerous glacial landforms but also created space for the formation of glacial lakes. The role of the glacial lake system in storing and redistributing glacial sedi- Land over the years.

CONFLICT OF INTEREST STATEMENT
The authors declare no conflicts of interest.

DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the corresponding author upon reasonable request.