Formation and disintegration of a high‐arctic ice‐cored moraine complex, Scott Turnerbreen, Svalbard

Sletten, Kari; Lyså, Astrid; Lønne, Ida

doi:10.1111/j.1502-3885.2001.tb01046.x

Cited by 58 publications

(34 citation statements)

References 47 publications

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“…The cause of the limited debris volume and relatively small number and size of constructional landforms on the north foreland likely relates to the fact that this side of the glacier has been influenced by a wide, single flow unit, which drains the Lomonosovfonna plateau, so the possibility of incorporating supraglacial debris was very limited and restricted only to the fringes of the flow units. Also potentially influential in debris provision is the possibility that the warmcold-based transition zone was spatially and temporally limited, resulting in the creation of only the outer moraine ridge by marginal debris entrainment during the LIA maximum, similar to some other glaciers around Svalbard Sletten, Lyså, & Lønne, 2001). Recession of the glacier since that time has most probably been continuous as no minor recessional moraines have been observed.…”

Section: Glacial Landsystemmentioning

confidence: 99%

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

2016

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A 1:4000 scale map of the terrestrial margins of the foreland of Nordenskiöldbreen depicts a polythermal glacial landsystem containing a record of the landform signatures of individual ice flow units that operate within the glacier snout. A 1:700 map provides a detailed overview of fluted terrain, based on unmanned aerial vehicle images captured in 2014. The pattern of landforms lying inside the Little Ice Age (LIA) latero-frontal moraine on the northern side of the fjord comprises a fluted till surface, which in turn grades into icemoulded bedrock. This signature records the recession of a single, wide ice flow unit, which was characterised by limited incorporation of subglacial material and restricted delivery of supraglacial debris. Inside the latero-frontal moraine on the south side of the fjord, a fluted surface is subordinate to a pronounced and large ice-cored moraine complex related to the confluence of five narrower ice flow units, each of which transported significant quantities of englacial and supraglacial debris at their suture zones as a series of longitudinal debris stripes. The suite of foreland landforms is diagnostic of both temperate subglacial and frozen-snout conditions, indicating the operation of a warm polythermal glacier fed by multiple flow units during the LIA. ARTICLE HISTORY

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Section: Glacial Landsystemmentioning

confidence: 99%

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

2016

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“…Neoglacial moraines in Svalbard have been used as analogues for Pleistocene moraines in the mid-latitudes (e.g., Hambrey et al, 1997;Bennett et al, 1998;Graham and Midgley, 2000); however, many contain buried ice (e.g., Bennett et al, 1996Bennett et al, , 2000Lyså and Lønne, 2001;Sletten et al, 2001;Lønne and Lyså, 2005;Schomacker and Kjaer, 2008;Evans, 2009;Midgley et al, 2013;Ewertowski, 2014;Ewertowski and Tomczyk, 2015;, which means that there is potential for significant landform change associated with the ablation of buried ice. The validity of such analogues relies upon a lack of buried ice in the proglacial area in order for the landforms to be preserved through a period of complete deglaciation.…”

Section: Introductionmentioning

confidence: 99%

Evolution of high-Arctic glacial landforms during deglaciation

et al. 2018

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Glacial landsystems in the high-Arctic have been reported to undergo geomorphological transformation during deglaciation. This research evaluates moraine evolution over a decadal timescale at Midtre Lovénbreen, Svalbard. This work is of interest because glacial landforms developed in Svalbard have been used as an analogue for landforms developed during Pleistocene mid-latitude glaciation. Ground penetrating radar was used to investigate the subsurface characteristics of moraines. To determine surface change, a LiDAR topographic data set (obtained 2003) and a UAV-derived (obtained 2014) digital surface model processed using structure-from-motion (SfM) are also compared. Evaluation of these data sets together enables subsurface character and landform response to climatic amelioration to be linked. Ground penetrating radar evidence shows that the moraine substrate at Midtre Lovénbreen includes ice-rich (radar velocities of 0.17 m ns (mean thresholded rate of −4.39 m over the 11-year observation period). However, the debris-rich zones show a relatively low rate of surface change (mean thresholded rate of −0.98 m over the 11-year observation period), and the morphology of the debris-rich landforms appear stable over the observation period. A complex response of proglacial landforms to climatic warming is shown to occur within and between glacier forelands as indicated by spatially variable surface lowering rates. Landform response is controlled by the ice-debris balance of the moraine substrate, along with the topographic context (such as the influence of meltwater). Site-specific characteristics such as surface debris thickness and glaciofluvial drainage are, therefore, argued to be a highly important control on surface evolution in ice-cored terrain, resulting in a diverse response of high-Arctic glacial landsystems to climatic amelioration. These results highlight that care is needed when assessing the long-term preservation potential of contemporary landforms at high-Arctic glaciers. A better understanding of ice-cored terrain facilitates the development of appropriate age and climatic interpretations that can be obtained from palaeo ice-marginal landsystems.

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“…Boulton, 1967Boulton, , 1968Boulton, , 1970aBoulton, , b, 1972Bennett et al, 1996Bennett et al, , 2000Hambrey et al, 1997;1999;Hambrey, 2001, 2003;Lyså and Lønne, 2001;Sletten et al, 2001;Lønne and Lyså, 2005;Midgley et al, 2007Midgley et al, , 2013Ewertowski et al, 2012). Quantitative studies of Svalbard glaciers, however, have concentrated mainly on transformations in glacier geometry, dynamics and mass balance (e.g.…”

Section: Introductionmentioning

confidence: 99%

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

Ewertowski

Tomczyk

2015

Geomorphology

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Extensive ice-cored moraine complexes are common elements, marking the last advance of many Svalbard glaciers. Sediment gravity flows are among the most dynamic processes, transforming these landforms. The short-term (yearly and weekly) dynamics of mass-wasting processes were studied in a cm-scale using repetitive topographic scanning. We monitored several active sites on the forelands of two glaciers, Ebbabreen and Ragnarbreen, both of which are located near the Petuniabukta at the northern end of Billefjorden in Spitsbergen.The surveys indicate high dynamic rates of landforms' transformation. The mean annual volume loss of sediments and dead-ice for the most active parts of the moraines was up to 1.8 m a -1 . However, most of the transformation occurred during summer, with the short-term values of mean elevation changes as high as −104 mm day −1 . In comparison, the dynamics of the other (i.e. non-active) parts of the ice-cored moraines were much lower, namely, the mean annual lowering (attributed mainly to dead-ice downwasting) was up to 0.3 m a -1 , whereas lowering during summer was up to 8 mm day −1 . Our results indicate that in the case of the studied glaciers, backwasting was much more effective than downwasting in terms of landscape transformation in the glacier forelands. However, despite the high activity of localised mass movement processes, the overall short-term dynamics of ice-cored moraines for the studied glaciers were relatively low. We suggest that as long as debris cover is sufficiently thick (thicker than the permafrost's active layer depths), the mass movement activity would occur only under specific topographic conditions and/or due to occurrence of external meltwater sources and slope undercutting. In other areas, ice-cored moraines remain a stable landsystem component in a yearly to decadal time-scale. Graphical abstractPlease cite this article as: Ewertowski, Marek W., Tomczyk, Aleksandra M., Quantification of the ice-cored moraines' short-term dynamics in the high-Arctic glaciers Ebbabreen and Ragnarbreen, Petuniabukta, Svalbard, Geomorphology 234 (2015): 211-227,

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Formation and disintegration of a high‐arctic ice‐cored moraine complex, Scott Turnerbreen, Svalbard

Cited by 58 publications

References 47 publications

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

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

Evolution of high-Arctic glacial landforms during deglaciation

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

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