Proglacial Valley Research Articles

Similarity and Change Detection of Relief in a Proglacial River Valley (Scott River, SW Svalbard)

This study focuses on contemporary geomorphic changes in the proglacial valley floor of the Scott River catchment (northwest of Wedel Jarlsberg Land, southwestern Spitsbergen). The similarity and variability of landforms along the entire 3.3 km length of the unglaciated valley floor was assessed using precision terrestrial laser scanning (TLS) measurements made in July/August 2010–2013. Digital terrain models (DTMs) were generated from the high-resolution TLS survey data, followed by a geomorphon map, which was then used for a similarity and changes of morphology analysis performed with GeoPAT2 software. The study revealed a large spatial variation of contemporary processes shaping the valley floor and changes in its morphology. Their spatial distribution relates to the geologically determined split of the valley floor into three morphological zones separated by gorges. The upper gorge cuts the terminal moraine rampart, which limits the uppermost section of the valley floor, which is up to 700 m wide and is occupied by the outwash plain. The study showed that this is the area characterised by the greatest dynamics of contemporary geomorphic processes and relief changes. The similarity index value here is characterised by a large spatial variation that in some places reaches values close to 0. In the middle section stretching between the upper gorge (cutting the terminal moraine) and the lower gorge (cutting the elevated marine terraces), a much smaller variability of processes and landforms is observed, and the found changes of the valley floor relief mainly include the area of braided channel activity. Similarity index values in this zone do not fall below 0.65. The lowest section, the mouth of the alluvial fan, on the other hand, is characterised by considerable spatial differentiation. The southern part of the fan is stable, while the northern part is intensively re-shaped and has a similarity index that locally falls below 0.5. The most dynamic changes are found within the active channel system along the entire length of the unglaciated section of the Scott River. The peripheral areas, located in the outer zones of the valley floor, show great stability.

Preliminary Results of the Introduction of Dicotyledonous Meadow Species

The reintroduction and introduction of native plant species is becoming more and more important in the restoration of plant communities. The study aimed to determine the possibility of predicting the effectiveness of the introduction of dicotyledonous species into impoverished patches of meadows in the landscape nature reserve in the proglacial valley of the Vistula River (Poland). Fourteen species planted into the soil from seedlings, after growing them from seeds in pots, in pure stands were assessed. Field studies were carried out in 2015–2017 on post-bog soil. Parameters of plant development and growth that were analysed included, among others, range, condition and height of shoots (vegetative and generative). Based on the biometric parameters, a statistical analysis (PCA, analysis of variance, decision tree) was performed. It was found that the range, i.e., the spread of the population, did not determine the classification of species into groups with a different nature of development after introduction. This classification was mainly determined by the plant condition in the following years after the introduction (over 3.4 on a 5-point scale), and the occurrence of generative shoots in the second year after planting. The group with the highest potential efficiency of introduction included three species: Achillea millefolium, Hypericum perforatum, Veronica longifolia. The failure of the introduction of other species resulted from their life form (two years old) and unfavourable weather conditions in the third year of study (2017), due to the high level of groundwater.

Application of geomorphons for analysing changes in the morphology of a proglacial valley (case study: The Scott River, SW Svalbard)

The progressive degradation of the cryosphere of High-Arctic areas causes an increase in the dynamics of geomorphic processes that shape the valleys of rapidly retreating glaciers. Those especially sensitive to global environmental changes are the small, land-ending valley glaciers that are in the phase of strong retreat. Under these conditions, the river valley's floors that are drained by proglacial waters are constantly undergoing intensive changes. For the analysis of these changes, two methods were used simultaneously (as a synthesis) to allow for quantitative and qualitative evaluation. The first one is the increasingly more common DoD method (DEM of difference), which allows quantifying volumetric changes as a result of topographic differentiation. The second one, which was applied for the first time on a small-valley spatial scale, is the geomorphons method that makes it possible to assess the stability of landforms and to determine the directions of their new development. To judge the applicability (advantages and disadvantages) of both methods for analysis of geomorphic changes in rapidly changing proglacial environments, the study was carried out over a 3.3 km distance of the non-glaciated section of the Scott River valley course (NW Wedel-Jarlsberg Land, SW Svalbard). This area (1.3 km2) is currently shaped by a braided gravel-bed river. More accurately, the study focused on the section spanning from the glacier terminus, which is the source of the Scott River, to its outlet at the Rechersche Fjord (Bellsundfiorden). The foundation for the development of comparative elevation models was a collection of terrestrial laser scanning (TLS) surveys that were taken with a Leica ScanStation C10 scanner during the 2010 and 2013 snowmelt seasons. On the basis of these surveys and with the use of TIN interpolation, high-resolution (0.2 m) digital terrain models (DTMs) were generated. The DTM models that had been prepared in this manner were used for the analysis of surface changes by employing Geomorphic Change Detection (GCD) software, and by simultaneously generating geomorphons maps for four selected test areas that covered characteristic fragments of the valley bottom (1- on the close forefield of the Scott Glacier terminus; 2- in the immediate vicinity of the narrow valley outlet at the foot of the marginal moraine ridge; 3- in the enlargement of the central section of the non-glaciated valley floor; 4- within the alluvial fan (outlet to the fjord)). A comparison of the obtained results (DoD and geomorphons maps; zonal statistics) as well as a compilation of both the quantitative assessment of the scale of changes and the qualitative assessment of the transformation's direction allowed for reconstructing the range and rate of three-year-long changes in morphology at the analysed sections of the valley floor. It was found that the pattern and rate of changes were closely related to the location of the test areas in the Scott River's catchment system. Significant differences in the dynamics of processes shaping the valley landforms along the longitudinal valley course were found.

Hydrogeology of an alpine talus aquifer: Cordillera Blanca, Peru

The dramatic loss of glacial mass in low latitudes is causing shifts in downstream water availability and use during the driest months of the year. The world’s largest concentration of tropical glaciers lies in the Cordillera Blanca range of Peru, where glacial runoff is declining and regional stresses are emerging over water resources. Throughout the Cordillera Blanca, groundwater inputs from alpine meadow–talus complexes, locally known as pampas, supply proglacial streams with up to 80% of their flow during the region’s dry season. Structural knowledge of the pampa aquifers is needed to estimate their drainable groundwater storage capacity and residence time, to elucidate the role and importance of alpine groundwater storage in the regional water budget of the Cordillera Blanca. To understand the structure of these proglacial aquifers, multiple near-surface geophysical methods were implemented in a proglacial valley near dense networks of spring-fed tributaries. Geophysical results and borehole logs suggest groundwater is stored in a confined aquifer composed of buried talus deposits overlain by lacustrine clay, while deeper portions of the unit, 10–15 m in depth, are relatively clay-free and more hydraulically conductive. Based on these findings and assumptions of aquifer porosity, the pampas of the Callejon de Huaylas may store from 0.006 to 0.02 km3 of groundwater. Furthermore, these findings suggest that the talus aquifers of the Cordillera Blanca were formed in proglacial lakes, followed by infilling with fine lacustrine sediments that confine lower units and allow for groundwater discharge to springs via macropores and preferential flow.

Quantifying groundwater–surface water interactions in a proglacial valley, Cordillera Blanca, Peru

AbstractA myriad of downstream communities and industries rely on streams fed by both groundwater discharge and glacier meltwater draining the Cordillera Blanca, Northern Peruvian Andes, which contains the highest density of glaciers in the tropics. During the dry season, approximately half the discharge in the region's proglacial streams comes from groundwater. However, because of the remote and difficult access to the region, there are few field methods that are effective at the reach scale to identify the spatial distribution of groundwater discharge. An energy balance model, Rhodamine WT dye tracing, and high‐definition kite‐borne imagery were used to determine gross and net groundwater inputs to a 4‐km reach of the Quilcay River in Huascaran National Park, Peru. The HFLUX computer programme (http://hydrology.syr.edu/hflux.html) was used to simulate the Quilcay River's energy balance using stream temperature observations, meteorological measurements, and kite‐borne areal photography. Inference from the model indicates 29% of stream discharge at the reach outlet was contributed by groundwater discharge over the study section. Rhodamine WT dye tracing results, coupled with the energy balance, show that approximately 49% of stream water is exchanged (no net gain) with the subsurface as gross gains and losses. The results suggest that gross gains from groundwater are largest in a moraine subreach but because of large gross losses, net gains are larger in the meadow subreaches. These insights into pathways of groundwater–surface water interaction can be applied to improve hydrological modelling in proglacial catchments throughout South America. Copyright © 2016 John Wiley & Sons, Ltd.

Late Pleistocene glaciofluvial sedimentation in Gariūnai–Pagiriai proglacial valley, SE Lithuania

The results of studies of glaciofluvial sediments and their sedimentation in a progla cial valley in the northern part of SE Lithuanian outwash plain are presented. The aim of the study was to compare the features of sediments in the geomorphologically well expressed Gariūnai–Pagiriai proglacial valley with the rest part of the SE Lithuanian Sandy Plain in which the complexity of proglacial fluvial sedimentation was revealed during the resent investigations. The change of depositional structures of sandy sediments and grain size distribution in vertical sediment sequences was studied for lithofacies analysis. The studies carried out let to interpret the sedimentation conditions of deposits in the proglacial valley as a meandering stream of SE direction, which downstream turns SW and intersects the SE Lithuanian Sandy Plain composed of braided stream outwash sediments. Lithofacies of proglacial valley deposits were distinguished in the deposit sequences due to a qualitative sedimentological research. Mid-channel and side-channel bar deposits of the proglacial valley were described and conditions of their sedimentation were evaluated. It was interpreted that formation of glaciofluvial terraces in the proglacial valley took place in several stages under the changing mode of ice meltwater flow and the steady source of clastic sediment material.

Modelling sediment load in a glacial meltwater stream in western Norway

Summary The objective of this work is to provide a tool for modelling and temporal reconstruction of the sediment load in a proglacial valley in Norway. For this purpose, we have developed the SEdiment Load CLImatological Model ( SELCLIM ) to predict climate-induced sediment load based on seasonal precipitation and temperature inputs. The model is tested using observational data for the period 1968–2000. The main development of the Nigardsbreen Valley system is likely the combined effects of pulsed erosion over multiple nivoglacial cycles of expansion and retreat at interdecadal scale, pulsed flushes and runoff-erosivity erosion. The model used discharge and surrogate predictors to model annual sediment load. The study attempted at relating historical and instrumental glacier front movement, thermal spring–summer conditions, snow and glacier ice ablation, and summer rainfall with total summer sediment accumulation to assess interannual to centennial-scale variability of sediment load during the Little Ice Age glacier expansion and following retreat at Nigardbreen.

Initial stages of weathering and soil formation in the Morteratsch proglacial area (Upper Engadine, Switzerland)

Investigations in Alpine soils indicate that mineral weathering is much faster in ‘young’ soils (< 1000 yr) than in ‘old’ soils (∼ 10,000 yr). However, little is known about the initial stages of weathering and soil formation, i.e. during the first decades of soil genesis. In this study we investigated rock-forming minerals weathering at very early stages of soil formation. Due to the continuous retreat of the Morteratsch glacier (Upper Engadine, Swiss Alps), the proglacial area offers a full time sequence from 0 to 150 yr old surfaces. A low slope and the absence of glacier which might have interrupted soil formation processes, contributed to the choice of the Morteratsch proglacial valley for this case study. The area is well documented regarding vegetation and soils. The tectonic unit is the Bernina-crystalline, which is mainly constituted of granitoid rocks. Consequently, the glacial till has an acidic character. Mineralogical measurements were carried out on the soil fraction < 2 mm using XRD and DRIFT for qualitative and quantitative phase analysis. In addition, chemical analyses of the stream water from the main channel, tributaries and of rainwater were performed with a special focus on Ca/Sr and Sr isotope ratios ( 87Sr/ 86Sr). Furthermore, the accumulation of organic matter within the time sequence and physical soil properties were measured. Decreasing grain size with time shows active physical weathering processes. Soil organic matter has been accumulated during 150 yr at very high rates. Special emphasis has been given to chemical weathering and to the formation and transformation mechanisms of minerals. Of special interest were biotite, chlorite, epidote, plagioclase and calcite. Biotite has been continuously transformed into illite-like components. Within 150 yr, the concentration of epidote significantly decreased. The high Ca/Sr as well as 87Sr/ 86Sr ratios in the stream and spring waters confirmed that Ca bearing minerals are weathering and transforming at very high rates in the proglacial area. Also in cryic, ice-free environments, chemical weathering rates are high leading to the formation and transformation of minerals. Disseminated calcite in granitoid rocks, not confined to sedimentary carbonate rocks, also plays a role in subglacial environments. It is, however, not known for how long such an influence is significant and measurable. The high Ca/Na and Ca/Sr ratio in the stream and tributary waters showed that calcite contributes to the supply of soluble Ca, although the ion activity product calculations clearly demonstrated that the waters were undersaturated with respect to this mineral.

Human impact on wetland flora of the Warsaw-Berlin proglacial valley

Central Poland is a region with low wetland richness. Its most valuable meadows and peatlands are situated in the eastern part of the Warsaw-Berlin proglacial valley, between Łowicz and Dąbie. This largest wetland area of Central Poland covers ca. 20 000 hectares, with a mosaic of meadows, forests, various wetlands, and small areas of arable land. Over the last 50 years, a negative impact of agriculture has been observed in the plant cover at the bottom of the proglacial valley, e.g. extinction of many wetland plant species. The main aim of this research was to determine the impact of agriculture on floristic diversity and natural condition of the wetland. In the 77 studied squares (1 km2each), we recorded ca. 600 species of vascular plants. The squares greatly varied in species composition and number. The long-term human pressure on the proglacial valley flora caused its significant degradation: with the progress of transformation of the area, the participation of anthropophytes and apophytes increases. Additionally, intensive agriculture in the proglacial valley causes extinction of species from wetland habitats.

Landscape and sediment processes in a proglacial valley, the Mittivakkat Glacier area, Southeast Greenland

Geografisk Tidsskrift, Danish Journal of Geography 108(1):97–110, 2008 During the Little Ice Age (LIA), the present proglacial Mittivakkat Valley, stretching 1.5 km ENE-WSW from the terminus of the Mittivakkat Glacier tongue to a delta terminating in the Sermilik Fjord, Southeast Greenland, was transgressed by the glacier as indicated by a terminal moraine near the valley mouth. The first recordings of the glacier terminus in 1933 show a frontal retreat of about 300 m since the Little Ice Age (LIA). Since then, the glacier has retreated another 1200 m leaving a valley train characterized by steep slopes flanking a 150–300 m wide flat-bottomed, sediment-floored trough. The larger part of the valley is floored by fluvial sediments and shows a typical valley sandur stream, the Mittivakkat stream, with one or two main water-channels, which branches out in a braided stream system with numerous intervening channel bars. In the outer part of the valley train, the Mittivakkat stream is erosive and divides around remnants of ground moraine, end-moraines, and outwash with abandoned meltwater channels. In this area some bank erosion is seen, but rejuvenation of older stream channels takes place during spring time when snowbridges cover the recent outlet and force the meltwater to follow the older channels at a higher level. Most recently, the seaward side of the outermost end-moraine ridge has been eroded by the sea, probably because the delta area is degrading. This could be a result of a decreased delivery of glaciofluvial sediments, due to the sink effect of the proglacial valley, but also because of less sea ice during summer periods and a more recent shift in wind directions during open water periods towards south and west. Geoelectric measurements (Schlumberger) along a number of traverses show sediment thicknesses in the valley trough of 6–23 m, which suggest that 2.2 x 106 m3 of sediment has been deposited in the valley. The estimated volume of glaciofluvial sediments deposited in the valley and delta is 9.9 x 106 m3. Recent sediment transport from the glacier basin of 18.4 km2 through the Mittivakkat Valley to the Sermilik Fjord at the mouth of the valley has been monitored. The annual average is around 7,000 m−3. The investigations confirm that a slight net deposition takes place in the upper part of the valley, showing that the proglacial valley will trap more of the sediment released by glacial erosion if the Mittivakkat Glacier continues to retreat. Thus, the investigation demonstrates the close interaction between the different morphological zones in a proglacial sediment transport system.

Patterns of Late Pleistocene proglacial fluvial sedimentation in the SE Lithuanian Plain

We investigated proglacial fluvial sedimentation processes in the SE Lithuanian Plain by means of lithofacies analysis. The main parameters on which interpretations were based, were depositional structures of sandy sediments, paleohydraulic parameters and grain-size distribution. The development of the SE Lithuanian Plain illustrates the phenomenal shift of proglacial fluvial sedimentation from outwash plain to ice-marginal river during the ice retreat of the last glaciation. Three facies assemblages of braidplain deposits and two facies assemblages of palaeovalley deposits were distinguished in the sandy plain by means of qualitative and quantitative sedimentological research. This raises the question how the commonly accepted development of a SE orientated outwash plain could turn into an almost perpendicular (SW running) ice-marginal river. The vertical and lateral transitions of outwash plain facies present a classical example of braidplain evolution on slightly inclined lowlands, with well expressed proximal, middle and distal parts. Mid- and side-channel (point-bar) deposits of the proglacial valley point, however, which is unusual for proglacial fluvial systems, to a meandering character of the ice-marginal river. River types of various scale show a change from braided into meandering in the proglacial subenvironment. Lithofacies analysis and paleohydraulic parameters show distinct differences of the hydrodynamic regime during the first stage of the sandy plain development: from sedimentation on an outwash plain in a proglacial valley to sedimentation on a braidplain in a wide ice-marginal valley. The outwash system is characterized by a distinct downstream decrease in energy, whereas the ice-marginal river maintained most of its power and velocity.

Meteorological observations 2004 at the Sermilik Station, Ammassalik Island, Southeast Greenland

Geografisk Tidsskrift, Danish Journal of Geography 106(1): 131–140, 2006 Meteorological stations have been in operation since 1993 at Sermilik (65°40'N, 38° 10W), Ammassalik Island, southeast Greenland. This note presents meteorological observations including snow cover and ground temperature for the year 2004, and orographic effect for liquid and solid precipitation from 2002 to 2004, between the two meteorological stations, Station Nunatak (515 m a.s.l.) and Station Coast (25 m a.s.l.). Since August 2004 air temperature has been measured in the inner proglacial valley, with the purpose among others, to study air temperature differences through the valley. Furthermore, manual measurements of air temperature, wind speed, and relative humidity for August 2004 are presented to illustrate the transect variation from the coast to the glacier terminus, through the proglacial valley.

Coastal Environmental Changes Revealed in Geophysical Images of Nantucket Island, Massachusetts, U.S.A.

Ground-penetrating radar surveys along a highly dynamic, paraglacial coastline of Nantucket Island, Massachusetts, reveal geological signatures of coastal environmental changes that are presently masked by coastal dunes and vegetation. The high-resolution geophysical records reveal 1) the geometry and genesis of discontinuities produced by spit migration, 2) thickness and progradation style of beach and nearshore deposits, 3) subsurface expression of a paleo-scarp beneath a prograded coastal sequence, and 4) dimensions and mode of infilling of a proglacial valley containing an ephemeral inlet channel. This study illustrates the value of geophysical research in complementing and extending the historical shoreline change data, providing the basis for quantitative assessment of landscape change, and offering a more complete picture of Holocene coastal dynamics.

Late Autumn Runoff and Sediment Transport in a Proglacial Drainage System, Sermilik, East Greenland

Hasholt, Bent: Late Autumn Runoff and Sediment Transport in a Proglacial Drainage System, Sermilik, East Greenland. Geografisk Tidsskrift 93:1–5. Copenhagen 1993. Field investigations of runoff and sediment transport were carried out in the proglacial area of the Mitdluagkat Glacier drainage basin in September 1992. Runoff in the proglacial stream was 32 l/s/km2. Runofffrom the northern flank of the glacier at the outlet of Lake Kugssuag was 14 l/s/km2. Mean daily sediment transport was 17 t/d in the proglacial valley and 0.2 t/d at the outlet of the lake. It was clearly demonstrated that the formation of frazil ice and anchor ice caused increased sediment transport, dominating the total load of the proglacial stream during the measuring period 2/9–19/9.

Sediment Transport in a Proglacial Valley, Sermilik, East Greenland

Hasholt, Bent: Sediment Transport in a Proglacial Valley, Sermilik, East Greenland, Geografisk Tidsskrift 92:105–110, Copenhagen 1992. Detailed investigations of sediment transport have been carried out in a proglacial valley at the Mitdluagkat Glacier in East Greenland. The results from 1989, 1990 and 1991 have been compared with earlier measurements of sediment transport. The hydrologie regime will be described and the effect of the development of an icing on the fluvial transport will be discussed.

Soil formation as an indication of relative age of glacial deposits in Eastern Greenland

Jakobsen, Bjarne Holm: Soil formation as an indication of relative age of glacial deposits in Eastern Greenland. Geografisk Tidsskrift 90: xx-xx Copenhagen 1990. A chrono-sequence of soils has been studied in a proglacial valley extending from the Midtluagkat Glacier on the island Angmags-salik Ø in Eastern Greenland. The relative age of soils and a probable sequence of especially translocation processes are discussed in relation to soil characteristics.

Age determination of intermoraine areas, Austerdalen, southern Norway

This paper is concerned with the size variation of thalli of the lichen Rhizocarpon geographicum agg. on intermoraine surfaces in the proglacial valley of Austerdalen, southern Norway, and with the use of thallus dimensions for both relative and absolute dating of intermoraine deposits. Measurements of the five largest lichens in 200 m2 search areas at 255 sites show significant cross‐valley and down‐valley variations, with the smallest thalli located towards the centre of the valley and at up‐valley sites. This variation has been examined in greater detail by dividing the intermoraine areas into twelve morphological zones, for which geomorphological and stratigraphical relations enable the construction of a relative time sequence of formation. This relative time sequence was then found to he confirmed by mean values of measurements of the largest lichen thalli in 100 m square quadrats within each morphological zone. This approach has allowed not only the relative age of morainic and intermorainic deposits to he established from geomorphological evidence but also, using tentative dates for the moraines, the construction of a chronology of moraine and intermoraine depositional events.