decadal evolution of a very small heavily debris covered glacier in an alpine permafrost environment glacier response to climate forcing can be heterogeneous and complex depending on glacier system characteristics this article presents the decadal evolution of the tsarmine glacier swiss alps a very small and heavily debris covered cirque glacier located in the alpine periglacial belt archival aerial photogrammetry and autocorrelation of orthophotos were used to compute surface elevation volume and geodetic mass changes as well as horizontal displacement rates for several periods between 1967 and 2012 a gpr survey allowed us to investigate glacier thickness 15 m mean and volume 4 10 6 m 3 in 2015 and to anticipate its future evolution different dynamics occurred in recent decades because of the heterogeneous surface characteristics the climate sensitive upper debris free zone contrasts with the progressively stagnant heavily debris covered glacier tongue between 1967 and 2012 the glacier lost 1 3 of its initial volume 2 10 6 m 3 the average mass balance stabilised at 0 3 m w e a 1 since 1999 compared with other local glaciers the tsarmine glacier shows a particular decadal behaviour both in time divergence of mass balance since the 2000s and space inverted ablation pattern this might be explained by the combined influence of debris cover shadow snow redistribution and permafrost conditions on this very small glacier

occurrence of rocky and sedimentary glacier beds in the swiss alps as estimated from glacier inventory data the occurrence of rocky and sedimentary glacier beds in the swiss alps was investigated using two approaches 1 a detailed and systematic classification of glacier forefields in the completely revised swiss glacier inventory and 2 the application of an algorithm for estimating bed characteristics from glacier inventory data the algorithm is based on the assumption that the sediment balance of a glacierized catchment i e the ratio between debris input from the surrounding rock walls and debris evacuation by the meltwater stream determines the occurrence of rocky sedimentary or mixed beds the processes which govern the sediment balance within a glacierized catchment cannot be easily observed or measured in the field however the main factors reflecting them can be organized in the form of an erosion sedimentation index this index discriminates between glaciers eroding into bedrock and those building up thick sediment beds and thus allows for rough assessments concerning bed characteristics sedimentary and mixed sedimentary rocky glacier beds clearly predominate in the swiss alps but more detailed spatial analysis is required for better predictions

petrology of high pressure granulites from the eastern himalayan syntaxis the eastern himalayan syntaxis situated at the eastern terminus of the himalayas is the least known segment of the himalayas recent research in this area has revealed that the syntaxis consists of the gangdise the yarlung zangbo and the himalayan units each of which is bounded by faults the himalayan unit the northernmost exposed part of the indian plate mainly contains amphibolite facies rocks marked by the assemblages staurolite kyanite plagioclase biotite muscovite sillimanite and garnet amphibole plagioclase in the south to the north low to medium pressure granulite grade pelitic gneisses and marbles are present and are characterized by the assemblages garnet sillimanite k feldspar plagioclase or antiperthite biotite quartz spinel cordierite orthopyroxene in gneisses and anorthite diopside wollastonite and plagioclase diopside quartz phlogopite calcite in marbles within this unit the namula thrust system is a series of moderately north dipping structures that displaced the granulite facies rocks southwards over the amphibolite facies rocks high pressure granulites occur as relics within these granulite facies rocks and contain garnet kyanite granulite and garnet clinopyroxenite the peak assemblage of the garnet kyanite granulite includes garnet core part kyanite ternary feldspar quartz rutile sillimanite garnet rim part k feldspar oligoclase ilmenite biotite and spinel albite biotite or spinel cordierite orthopyroxene which are coronas around sillimanite and garnet are retrograde products of this peak assemblage another peak assemblage includes very high ca garnet cao 32 34 wt alm10 grs 80 and diopside cao 22 24 wt scapolite meionite quartz and accessory al bearing titanite al2o3 4 4 5 wt the diopside has kink bands partial or complete breakdown of ca rich garnet during post peak metamorphism produced pseudomorphs and coronas consisting of fine grained symplectic intergrowths of hedenbergite and anorthite thermobarometric estimates in combination with reaction textures mineral compositions and recent experimental studies indicate that these peak assemblages were formed at p c 1 7 1 8 gpa t c 890 c and the retrograde assemblages experienced near isothermal decompression to p 0 5 0 1 gpa t 850 50 c the whole rock compositions indicate that marble and pelite are plausible candidates for the protoliths these facts suggest the following 1 sedimentary rocks were transported to upper mantle depths and equilibrated at those conditions to form these high pressure granulites which were then emplaced into the crust quickly during the rapid exhumation of these rocks the earlier high pressure assemblages were overprinted by the later low to medium pressure assemblages that is the high pressure granulite belt formed in the syntaxis 2 the namula thrust system is an important tectonic boundary in the syntaxis or even in the higher himalaya more generally

proglacial lakes character behaviour and geological importance proglacial lakes are ubiquitous within the quaternary record and can provide exceptional breadth and depth of palaeoenvironmental information present deglaciation is increasing the number and size of proglacial lakes around the world this study provides a synthesis of knowledge on proglacial lake character and behaviour and critically evaluates the importance of proglacial lakes from a geological perspective we show how ice marginal or ice contact lakes and other distal proglacial lakes can be distinguished from each other by geomorphological sedimentological chemical and biological characteristics the key controls on proglacial lake geomorphology and sedimentology are outlined and discussed proglacial lakes can exacerbate mountain glacier and ice sheet margin ablation via mechanical and thermal stresses but very large lakes can moderate summer air temperatures and relatively retard summer ice ablation proglacial lakes interrupt meltwater flux and are very efficient sediment traps hydrological routing and consequent geomorphological activity can be radically modified by sudden drainage of proglacial lakes and resultant glacial lake outburst floods exceptionally large proglacial lake drainages affected global ocean circulation and global climate during the quaternary overall analyses of proglacial lakes can provide a valuable insight into i patterns character and behaviour of mountain glaciers ice sheets and glaciations and ii the impacts of past present and future deglaciation

an assessment of landform composition and functioning with the first proglacial systems dataset of the central european alps abstract proglacial systems are enlarging as glacier masses decline they are in a transitory state from glacier dominated to hillslope and fluvially dominated geomorphological processes they are a very important meltwater sediment and solute source this study makes the first quantitative systematic and regional assessment of landform composition and functioning within proglacial systems that have developed in the short term since the little ice age lia proglacial system extent was thus defined as the area between the lia moraine ridges and the contemporary glacier we achieved this assessment via a series of topographic analyses of 10 m resolution digital elevation models dems covering the central european alps specifically of austria and switzerland across the 2812 proglacial systems that have a combined area of 933 km2 the mean proportional area of each proglacial system that is directly affected by glacial meltwater is 37 however there are examples where there is no glacial meltwater influence whatsoever due to complete disappearance of glaciers since the lia and there are examples where 90 of the proglacial area is probably affected by glacial meltwater in all of the major drainage basins the inn drava venetian coast po rhine rhone and danube the proportions of the combined land area belonging to each landform class is remarkably similar with 10 fluvial 35 alluvial and debris fans 50 moraine ridges and talus scree and 10 bedrock which will be very helpful for considering estimates of regional sediment yield and denudation rates we find groupings of the relationship between proglacial system hypsometric index and lithology and of a slope threshold discriminating between hillslope and fluvial dominated terrain both of which we interpret to be due to grain size we estimate of contemporary total volume loss from all of these proglacial systems of 44 m m3a 1 which equates to a mean of 0 3 mm a 1 contemporary surface lowering overall these first quantifications of proglacial landform and landscape evolution will be an important basis for inter and intra catchment considerations of climate change effects on proglacial systems such as land stability and changing water sediment and solute source fluxes our datasets are made freely available

short term geomorphological evolution of proglacial systems proglacial systems are amongst the most rapidly changing landscapes on earth as glacier mass loss permafrost degradation and more episodes of intense rainfall progress with climate change this review addresses the urgent need to quantitatively define proglacial systems not only in terms of spatial extent but also in terms of functional processes it firstly provides a critical appraisal of prevailing conceptual models of proglacial systems and uses this to justify compiling data on rates of landform change in terms of planform horizontal motion elevation changes and sediment budgets these data permit us to produce novel summary conceptual diagrams that consider proglacial landscape evolution in terms of a balance of longitudinal and lateral water and sediment fluxes throughout we give examples of newly emerging datasets and data processing methods because these have the potential to assist with the issues of i a lack of knowledge of proglacial systems within high mountain arctic and polar regions ii considerable inter and intra catchment variability in the geomorphology and functioning of proglacial systems iii problems with the magnitude of short term geomorphological changes being at the threshold of detection iv separating short term variability from longer term trends and v of the representativeness of plot scale field measurements for regionalisation and for upscaling we consider that understanding of future climate change effects on proglacial systems requires holistic process based modelling to explicitly consider feedbacks and linkages especially between hillslope and valley floor components such modelling must be informed by a new generation of repeated distributed topographic surveys to detect and quantify short term geomorphological changes

conditions for feedbacks between geomorphic and vegetation dynamics on lateral moraine slopes a biogeomorphic feedback window little ice age lateral moraines represent one of the most important sediment storages and dynamic areas in glacier forelands following glacier retreat simultaneous paraglacial adjustment and vegetation succession affect the moraine slopes geomorphic processes e g debris flows interrill erosion gullying solifluction disturb and limit vegetation development while increasing vegetation cover decreases geomorphic activity thus feedbacks between geomorphic and vegetation dynamics strongly control moraine slope development however the conditions under which these biogeomorphic feedbacks can occur are insufficiently understood and major knowledge gaps remain this study determines feedback conditions through the analysis of geomorphic and vegetation data from permanent plots in the turtmann glacier foreland switzerland results from multivariate statistical analysis i confirm that dryas octopetala l is an alpine ecosystem engineer species which influences geomorphic processes on lateral moraines and thereby controls ecosystem structure and function and ii demonstrate that biogeomorphic feedbacks can occur once geomorphic activity sufficiently decreases for d octopetala to establish and cross a cover threshold in the subsequent ecosystem engineering process the dominant geomorphic processes change from flow and slide to bound solifluction increasing slope stabilization induces a decline in biogeomorphic feedbacks and the suppression of d octopetala by shrubs we conceptualize this relationship between process magnitude frequency and species resilience and resistance to disturbances in a biogeomorphic feedback window concept our approach enhances the understanding of feedbacks between geomorphic and alpine vegetation dynamics on lateral moraine slopes and highlights the importance of integrating geomorphic and ecological approaches for biogeomorphic research copyright 2015 john wiley sons ltd

contemporary geomorphological activity throughout the proglacial area of an alpine catchment abstract quantification of contemporary geomorphological activity is a fundamental prerequisite for predicting the effects of future earth surface process and landscape development changes however there is a lack of high resolution spatial and temporal data on geomorphological activity within alpine catchments which are especially sensitive to climate change human impacts and which are amongst the most dynamic landscapes on earth this study used data from repeated laser scanning to identify and quantify the distribution of contemporary sediment sources and the intensity of geomorphological activity within the lower part of a glaciated alpine catchment odenwinkelkees central austria spatially geomorphological activity was discriminated by substrate class activity decreased in both areal extent and intensity with distance from the glacier becoming progressively more restricted to the fluvially dominated valley floor temporally geomorphological activity was identified on annual seasonal weekly and daily timescales activity became more extensive with increasing study duration but more intense over shorter timescales thereby demonstrating the importance of temporary storage of sediment within the catchment the mean volume of material moved within the proglacial zone was 4400 m 3 yr 1 which suggests a net surface lowering of 34 mm yr 1 in this part of the catchment we extrapolate a minimum of 4 8 mm yr 1 net surface lowering across the whole catchment these surface lowering values are approximately twice those calculated elsewhere from contemporary measurements of suspended sediment flux and of rates calculated from the geological record perhaps because we measure total geomorphological activity within the catchment rather than overall efflux of material repeated geomorphological surveying therefore appears to mitigate the problems of hydrological studies underestimating sediment fluxes on decadal annual time scales further development of the approach outlined in this study will enable the quantification of geomorphological activity alpine terrain stability and persistence of landforms

a probabilistic sediment cascade model of sediment transfer in the illgraben we present a probabilistic sediment cascade model to simulate sediment transfer in a mountain basin illgraben switzerland where sediment is produced by hillslope landslides and rockfalls and exported out of the basin by debris flows and floods the model conceptualizes the fluvial system as a spatially lumped cascade of connected reservoirs representing hillslope and channel storages where sediment goes through cycles of storage and remobilization by surface runoff the model includes all relevant hydrological processes that lead to runoff formation in an alpine basin such as precipitation snow accumulation snowmelt evapotranspiration and soil water storage although the processes of sediment transfer and debris flow generation are described in a simplified manner the model produces complex sediment discharge behavior which is driven by the availability of sediment and antecedent wetness conditions system memory as well as the triggering potential climatic forcing the observed probability distribution of debris flow volumes and their seasonality in 2000 2009 are reproduced the stochasticity of hillslope sediment input is important for reproducing realistic sediment storage variability although many details of the hillslope landslide triggering procedures are filtered out by the sediment transfer system the model allows us to explicitly quantify the division into transport and supply limited sediment discharge events we show that debris flows may be generated for a wide range of rainfall intensities because of variable antecedent basin wetness and snowmelt contribution to runoff which helps to understand the limitations of methods based on a single rainfall threshold for debris flow initiation in alpine basins

paraglacial response of steep sediment mantled slopes to post little ice age glacier recession in the central swiss alps this research assesses the morphological consequences of recent post little ice age paraglacial reworking of valley side sediment mantles in the european alps it aims to identify the extent and conditioning factors of slope adjustment at sites in the swiss alps model the temporal pattern and assess the rates of sediment reworking involved gully systems have cut into steep high level lateral moraines and debris cones have accumulated downslope debris flow is the dominant agent of sediment transfer factors controlling the extent of this activity include moraine slope gradient relief and moisture availability gullies appear to have reached their maximum dimensions within ca 50 yr of deglaciation after which gully relief is reduced by removal of inter gully slopes and gully infilling within 80 140 yr on the most recently deglaciated terrain minimum erosion rates average ca 95 mm yr 1 since gully initiation greatly exceeding normal erosion rates in other environments mean annual accumulation of a single debris cone since ice retreat was calculated to be ca 30 mm yr 1 implications of these findings are applied to patterns of paraglacial sediment mantled slope adjustment conceptualising paraglacial landscape response in terms of a sediment release exhaustion model and paraglacial landform succession copyright 2005 john wiley sons ltd

a multi dimensional analysis of pro glacial landscape change at solheimajokull southern iceland proglacial landscapes are some of the most active on earth previous studies of proglacial landscape change have often been restricted to considering either sedimentological geomorphological or topographic parameters in isolation and are often mono dimensional this study utilised field surveys and digital elevation model analyses to quantify planform elevation and volumetric proglacial landscape change at solheimajokull in southern iceland for multiple time periods spanning from 1960 to 2010 as expected the most intense geomorphological changes persistently occurred in the ice proximal area during 1960 to 1996 the proglacial river was relatively stable however after 2001 braiding intensity was higher channel slope shallower and there was a shift from overall incision to aggradation attributing these proglacial river channel changes to the 1999 jokulhlaup is ambiguous because it coincided with a switch from a period of glacier advance to that of glacier retreat furthermore glacier retreat of 40 m yr 1 coincided with ice marginal lake development and these two factors have both altered the proglacial river channel head elevation from 2001 to 2010 progressive increase in channel braiding and progressive downstream incision occurred these together probably reflecting stream power due to increased glacier ablation and reduced sediment supply due to trapping of sediment by the developing ice marginal lake overall this study highlights rapid spatiotemporal proglacial landscape reactions to changes in glacial meltwater runoff regimes glacier terminus position sediment supply and episodic events such as jokuhlaups recognising the interplay of these controlling factors on proglacial landscapes will be important for understanding the geological record and for landscape stability assessments

the role of sediment in controlling steady state bedrock channel slope implications of the saltation abrasion incision model abstract the saltation abrasion model is a mechanistic model for river incision into bedrock by saltating bedload which we have previously derived and used experimental data to constrain all parameter values here we develop a method for applying the saltation abrasion model at a landscape scale and use the model as a reference for evaluating the behavior of a wide range of alternative incision models in order to consider the implications of the saltation abrasion model as well as other models for predicting topographic steady state channel slope to determine the single valued discharge that best represents the effects of the full discharge distribution in transporting sediment and wearing bedrock we assume all runoff can be partitioned between a low flow and a high flow discharge in which all bedload sediment transport occurs during high flow we then use the gauged discharge record and measurements of channel characteristics at a reference field site and find that the optimum discharge has a moderate magnitude and frequency due to the constraints of the threshold of grain motion and bed alluviation by high relative sediment supply incision models can be classified according to which of the effects of sediment on bedrock incision are accounted for using the predictions of the saltation abrasion model as a reference we find that the threshold of motion is the most important effect that should be represented explicitly followed in order of decreasing importance by the cover effect the tools effect and the threshold of suspension effect models that lack the threshold of motion over predict incision rate for low shear stresses and under predict the steady state channel slope for low to moderate rock uplift rates and rock strengths models that lack the cover effect over predict incision rate for high sediment supply rates and fail to represent the degree of freedom in slope adjustment provided by partial bed coverage models that lack the tools effect over predict incision rate for low sediment supply rates and do not allow for the possibility that incision rate can decline for increases in shear stress above a peak value overall the saltation abrasion model predicts that steady state channel slope is most sensitive to changes in grain size such that the effect of variations in rock uplift rate and rock strength may affect slope indirectly through their possible but as yet poorly understood influence on the size distribution of sediments delivered to channel networks by hillslopes

properties of the 2003 lefkada ionian islands greece earthquake seismic sequence and seismicity triggering on 14 august 2003 lefkada island central ionian was strongly af fected by an mw 6 2 earthquake a dense temporary seismic network was installed one day after and accurately located hundreds of aftershocks that defined in detail the main rupture as well as the activity distribution in the neighboring fault segments the main rupture occupied the northwestern part of the coastline and trends north northeast south southwest in agreement with regional tectonics regional network locations were appropriately calibrated using the local network data allowing the relocation of the mainshock and strong m 4 5 or larger aftershocks during the first day intense aftershock activity took place up to 40 km beyond the southern end of the main rupture theoretical static stress changes from the mainshock give a preliminary explanation for the aftershock distribution aside from the main rupture as well as triggering of seismicity in the nearby kefalonia fault providing evidence for future seismic hazard ensuing from this fault

genesis stability and preservation potential of large lateral moraines of alpine valley glaciers towards a unifying theory based on findelengletscher switzerland abstract lateral moraines are prominent features of glaciated landscapes in high mountain environments and key landforms in glacier and palaeoclimatic reconstructions yet compared to smaller moraines they have been little studied and several aspects are not well understood we here present detailed sedimentological results from the lateral moraines of findelengletscher in sw switzerland to gain new insights into the formation of these landforms the lateral moraines studied here stand up to 140 m above the valley floor are over 3 km long and strongly asymmetrical in cross profile with distal slopes between 29 and 36 and proximal slopes that are commonly 41 64 but locally reach angles of up to 80 recorded lithofacies comprise loose clast and matrix supported stratified diamicts and intercalated sorted sediments in the distal slopes and near the crestline overconsolidated matrix supported massive and weakly stratified diamicts and streaked out sorted sediment lenses in the core and proximal slopes and partly intercalated dark brown layers overlain by loose and consolidated diamicts exposed in near vertical walls in the proximal flank these are interpreted as supraglacial debris flow units with intercalated fluvial wash horizons glaciotectonised and subglacial traction till with boudinaged and streaked out sediment lenses and palaeosoils overlain by sediment produced by overtopping of the former moraine surface during a subsequent advance of the glacier clast shape analysis and process observations reveal that the dominant mode of transport is subglacial and glaciofluvial and that the main mode of sediment delivery to the moraines is by debris flows after the material has been transferred from the bed via englacial debris bands and meltout at the surface this differs from previous studies that found that a supraglacial source was dominant sedimentary structures clast fabric and process observations during the 1979 1980 readvance of findelengletscher strongly suggest that proximal layers of reworked pre existing sediments and or basal traction zone till have been plastered onto the moraine core in several locations causing a high degree of overconsolidation and strongly clustered fabric eigenvalues s 1 0 94 with clustering parallel to the moraine crestline this suggests that a combination of basal lateral drag and lateral plastering produces the observed proximal stability and ensures a high preservation potential we develop a conceptual model that describes alpine lateral moraines as structurally complex landforms that do not just record a single event as often surmised and we discuss implications for palaeo glacier reconstruction and the application of numerical dating methods

proglacial erosion rates and processes in a glacierized catchment in the swiss alps in the swiss alps climatic changes have not only caused glacier retreat but also likely increased sedimentation downstream of glaciers this material either originates from below the glacier or from periglacial environments exposed as glaciers retreat and often consist of easily erodible sediment griesgletscher s catchment in the swiss alps was examined to quantify erosion in theproglacial area possible hydrological drivers and contributions of the sub and periglacial sources digital elevation models created from annual aerial photographs were subtracted to determine annual volume changes in the proglacial area from 1986 to 2014 these data show a strong increase in proglacial erosion in the decade prior to 2012 coincident with increasing proglacial area size however examination of the gradient between discharge and sediment evacuation and the modeled sediment transport could suggest that the proglacial area began to stabilize and sediment supply is limited the large influx of sediment into the proglacial reservoir which is roughly 2 5 times greater than the amount of sediment eroded from the proglacial area demonstrates the importance of subglacial erosion to the catchment s sediment budget although far more sediment originates subglacially erosion rates in the proglacial area are over 50 times greater than the rest of the catchment in turn both sub and periglacial processes in addition to constraining sediment supply must be considered forassessing future sediment dynamics as glacier area shrinks and proglacial areas grow

sediment export transient landscape response and catchment scale connectivity following rapid climate warming and alpine glacier recession abstract in the face of rapid climate warming rapid glacier recession should lead to a marked increase in the spatial extent of the paraglacial zone in glaciated drainage basins the extent of the paraglacial zone has been well established to be transient but there are very few studies of this transient response and what it means for sediment export there is good reason to expect that glacier recession could increase basin scale sediment connectivity as sediment becomes less dependent on glacier surface transport proglacial streams are more able to migrate laterally than subglacial streams and so access sediment for transport and glacier debuttressing may aid the development of gullies that can dissect moraines and so aid hillslope to proglacial zone connectivity by using records of the flushing of hydroelectric power installations we were able to develop a record of coarse sediment sand and gravel export from a basin with a rapidly retreating valley glacier the haut glacier d arolla from 1977 to 2014 modelling suggested that these data could only be partially controlled by transport capacity implying an important role for sediment supply and potentially for the influence of changing sediment connectivity indeed there was evidence of the effects of glacial debuttressing upon gullying processes and hence a possible increase in the ease of connection of upstream basins to the proglacial area more recently we were able to show possible temperature control on sediment export which may only have become apparent because of the progressive development of better sediment connectivity however whilst rapid glacier recession should result in theory in a progressive increase in connectivity of sediment sources to the basin outlet the supply to capacity ratio does not increase continually with glacier recession until maximum capacity is reached we identified two possible examples of why first gullying was also accompanied by the sediment accumulation at the base of moraines that was too coarse to be transported by the proglacial stream maintaining disconnection of the upper basins second the sediment capacity ratio appeared to be elevated during periods of more rapid retreat and we attribute this to the importance of a continued supply of unworked glacial till before fluvial reworking and sorting of freshly exposed sediment increased the resistance of sediment to entrainment and hence export rates thus the transient geomorphic response of glaciated basins to glacier recession may involve negative feedbacks that can reduce the extent to which increases in connectivity elsewhere in the basin lead to increased sediment export

changes in clemenceau icefield and chaba group glaciers canada related to hypsometry tributary detachment length slope and area aspect relations we compiled a detailed glacier inventory of 176 glaciers in the clemenceau icefield group cig and adjacent chaba group ch canada based on 2001 landsat 7 and 2000 03 aster satellite imagery and natural resources canada digital elevation models we used this inventory to measure length and mass balance changes and their possible controls a classification of glacier hypsometry in the form of a hypsometric index was used to assess the sensitivity of different glacier systems to a unit rise in snowline the altitude and aar of possible steady state elas was derived using several methods and was compared to late summer snowlines of 2001 we further compared planar glacier area to slope corrected area and compared the effects on the shape of the hypsometric curves on the total glacier area and on the aspect area distribution in 2001 cig had a glaciated area of 271 km 2 and had lost 42 km 2 since the mid 1980s ch had a total area of 69 km 2 and had lost 28 km 2 average retreat rates are 14 m a 1 for the period 1850 2001 n 39 and 21 m a 1 for 1986 87 2001 n 23 indicating accelerated retreat larger glaciers and those that experience tributary detachment tend to retreat faster the difference between planar and slope corrected glacier areas ranges from 5 to 20 with a 6 increase for the entire cig ch region the area increase does not change the shape of the hypsometric curves

postglacial adjustment of steep low order drainage basins canadian rocky mountains 1 it is generally argued that pleistocene glaciation results in increased sediment flux in mountain systems an important but not well constrained aspect of pleistocene glacial erosion is the geomorphic decoupling of cirque basins from main river systems this study provides a quantitative link between glacier induced basin morphology postglacial erosion and sediment delivery for mountain headwaters with basin area 28 respectively and ii larger fan sizes at outlets of noncirque basins compared to cirques although small headwater basins represent the steepest part of mountain environments and erode significant postglacial sediment the majority of sediment remains in storage under interglacial climatic conditions and does not affect large scale mountain river systems

contemporary suspended sediment dynamics within two partly glacierized mountain drainage basins in western norway erdalen and bodalen inner nordfjord abstract this paper focuses on environmental controls spatiotemporal variability and rates of contemporary fluvial suspended sediment transport in the neighboring partly glacierized and steep erdalen 79 5 km 2 and bodalen 60 1 km 2 drainage basins in the fjord landscape of the inner nordfjord in western norway field work including extended samplings and measurements was conducted since 2004 in erdalen and since 2008 in bodalen the distinct intra and inter annual temporal variability of suspended sediment transport found is mostly controlled by meteorological events with most suspended sediment transport occurring during pluvial events in autumn september november followed by mostly thermally determined glacier melt in summer july august and by mostly thermally determined snowmelt in spring april june extreme rainfall events 70 mm d 1 in autumn can trigger significant debris flow activity that can cause significant transfers of suspended sediments from ice free surface areas with sedimentary covers into main stream channels and is particularly important for fluvial suspended sediment transport in years with occurring relevant debris flow activity the total annual drainage basin wide suspended sediment yields are strongly determined by these single extreme events the proportion of glacier coverage followed by steepness of slopes and degree of vegetation cover in ice free surface areas with sedimentary covers are the main controls for the detected spatial variability of suspended sediment yields the contemporary sediment supply from glacierized surface areas and the jostedalsbreen ice cap through different defined outlet glaciers shows a high spatial variability the fact that the mean annual suspended sediment yield of bodalen is with 31 3 t km 2 yr 1 almost twice as high as the mean annual suspended sediment yield of erdalen 16 4 t km 2 yr 1 is to a large extent explained by the higher proportion of glacier coverage in bodalen 38 of the drainage basin surface area as compared to erdalen 18 of the drainage basin surface area and by a significantly higher sediment yield from the glacierized area of the bodalen drainage basin compared to the glacierized surface area in erdalen when looking at the total annual mass of suspended sediments being fluvially exported from both entire drainage basin systems the total amount of suspended sediments coming from the ice free drainage basin surface areas altogether dominates over the total amount of suspended sediments coming from the glacierized surface area of both drainage basins drainage basin wide annual suspended sediment yields are rather low when compared with yields of other partly glacierized drainage basin systems in norway and in other cold climate environments worldwide which is mainly due to the high resistance of the predominant gneisses towards glacial erosion and weathering the altogether only small amounts of sediments being available within the entire drainage basin systems the stable and nearly closed vegetation cover in the ice free surface areas with sedimentary covers and the efficiency of proglacial lakes in trapping sediments supplied by defined outlet glaciers both contemporary and long term suspended sediment yields are altogether supply limited contemporary suspended sediment transport accounts for nearly two thirds of the total fluvial transport and accordingly plays an important role within the sedimentary budgets of the entire erdalen and bodalen drainage basins

assessment of sediment sources throughout the proglacial area of a small arctic catchment based on high resolution digital elevation models abstract the article presents calculations of quantitative modifications of the morphology of selected subsystems of a glacial valley through i identification of the spatial distribution of important sources of sediment ii assessment of the spatiotemporal variety of sediment volume and landform morphology and iii assessment of the role of particular subsystems in sediment distribution the study involved a comparison of the results of field measurements from 2010 to 2013 performed in the scott glacier catchment 10 1 km2 in nw wedel jarlsberg land spitsbergen the assessment of the landform surface changes was performed by means of a precise terrestrial laser scanning tls survey the applied field and post processing techniques for oblique laser scanning permitted the acquisition of digital elevation data at a resolution 0 01 m and density 500 pt m 2 this allowed the development of a detailed terrain model and balancing spatial quantitative changes in six research test areas 10 000 m2 located within two subsystems of the catchment in a cascade arrangement in the alluvial valley floor subsystem the survey covered 1 the glacier terminus 2 the intramarginal outwash plain 3 the extramarginal braid plain and 4 the alluvial fan and in the slope subsystem 5 the erosional depositional slope in the gorge through terminal moraines and 6 the solifluction slope three zones differing in terms of the spatiotemporal dynamics of geomorphic processes were distinguished within the two analysed valley subsystems in the valley floor subsystem these are i the zone of basic supply distribution throughout the melting season and ii the redeposition zone distribution particularly during floods and in the slope subsystem iii zone of periodical supply distributed mainly in periods of increased precipitation and rapid increases in temperature in summer and during snow avalanches in winter the glacier and the landforms of the channel and valley floor as well as slope sediments transported as a result of mass wasting processes and activity of the active permafrost layer constitute important sources of sediment supply over a short 3 year timescale evidence of major changes of the surface morphology slopes floodplain and channel platform resulted in varied sediment budgets the subtraction of consecutive dems of the test areas located in the alluvial valley subsystem revealed downstream spatial and volumetric differentiation from the predominance of erosion 79 of volume 43 of area to the dominance of deposition 90 91 respectively in upper part of the valley floor to erosion predominance in the central 88 95 and lower 87 82 part of valley floor the test areas located on the slope subsystem showed the opposite relationship deposition dominance 88 of volume 80 of area in the upper gorge and erosion dominance 99 99 respectively in the lower part solifluction slopes the analysis of short time repeated surveys 3 week survey where volumes were calculated following dem subtraction showed increased deposition 82 of volume 79 of area for the alluvial fan and for solifluction slopes 70 57 respectively

integrating field measurements a geomorphological map and stochastic modelling to estimate the spatially distributed rockfall sediment budget of the upper kaunertal austrian central alps abstract the estimation of catchment scale rockfall rates relies on the regionalisation of local measurements here we propose a new framework for such a regionalisation by the example of a case study in the upper kaunertal austrian central alps 62 5 km 2 measurements of rockfall deposition during 12 months onto six collector nets within the study area were combined with published mean annual rates from the literature and a probability density function was fitted to these data a numerical model involving a random walk routing scheme and a one parameter friction model was used to simulate rockfall trajectories starting from potential rockfall source areas that were delineated from a digital elevation model rockfall rates sampled from the fitted probability density function were assigned to these trajectories in order to model the spatial distribution and to estimate the amount of rockfall deposition by recording all trajectories as edges of a network of raster cells and by aggregating the latter to landforms or landform types as delineated in a geomorphological map of the study area rockfall sediment flux from sources to different landforms could be quantified specifically the geomorphic coupling of rockfall sources to storage landforms and the glacial and fluvial sediment cascade was investigated using this network model the total rockfall contribution to the sediment budget of the upper kaunertal is estimated at c 8000 mg yr 1 16 5 of which is delivered to the glaciers and hence to the proglacial zone the network approach is favourable for example because multiple scenarios involving different probability density functions can be calculated on the basis of the same set of trajectories and because deposits can be back linked to their respective sources while the methodological framework constitutes the main aim of our paper we also discuss how the estimation of the budget can be improved on the basis of spatially distributed production rates

reconnaissance sediment budgets for lynn valley british columbia holocene and contemporary time scales volumes of erosional and depositional landforms were estimated by reconnaissance methods in a steep forested drainage basin in the coast mountains british columbia to examine what insight might be gained into the sediment budget in the absence of direct measurements of sediment transfer processes sediment transfers in postglacial and contemporary time were inferred on hillslopes from hillslopes to stream channels and within stream channels data were collected by aerial photographic analysis and field observation postglacial sediment sources are major gullies created by debris slides and flows failures in glaciolacustrine terraces and stream channel degradation depositional landforms consist of talus slopes and colluvial and alluvial fans contemporary sediment sources include debris slides and flows in established gullies and minor processes on hillslopes debris slide and debris flow volumes were calculated and other processes were estimated from regional values erosion rate averaged over postglacial time is 276 t km 2 a 1 0 15 mm a 1 surface lowering with gullies and stream channel degradation contributing 170 and 82 t km 2 a 1 respectively a terminal alluvial fan provides an independent check of the results in contemporary time erosion rates are calculated to be 350 t km 2 a 1 with debris flows and slides contributing nearly all of this sediment the contemporary rate is probably perturbed by recent land use history mass movement processes appear to be the dominant mechanism of sediment transfer and contributions from pleistocene valley deposits have declined significantly during holocene time resume les volumes de terrain erodes et deposes ont ete estimes par des methodes de reconnaissance dans un bassin de drainage boise a pentes abruptes des montagnes cotieres de la colombie britannique afin d etudier quelles connaissances sur le budget sedimentaire pourraient etre acquises en l absence de mesures directes du processus de transfert de sediments les transferts de sediments a l epoque post glaciaire et contemporaine ont ete inferes sur les flancs des cotes des flancs des cotes vers les chenaux des rivieres et dans les chenaux des rivieres les donnees proviennent de l analyse de photographies aeriennes et d observations sur le terrain les sources de sediments post glaciaires sont des ravines creees par des glissements et des coulees de debris des effondrements de terrasses glacio lacustres et la degradation de chenaux les formes de terrain creees par deposition comprennent des tabliers d eboulis et des deltas colluviaux et alluvionnaires les sources contemporaines de sediments comprennent des glissements et des coulees de debris dans des ravines etablies et des processus mineurs sur des pentes les volumes des glissements et des coulees de debris ont ete calcules et d autres processus ont ete evalues a partir de valeurs regionales la moyenne du taux d erosion pour la periode post glaciaire est de 276 tonnes km 2 a 1 abaissement de la surface de 0 15 mm a les ravines et la degradation des chenaux des ruisseaux contribuant respectivement 170 et 82 tonnes km 2 a 1 un delta alluvionnaire terminal permet une verification independante des resultats a l epoque contemporaine les taux d erosion sont calcules comme etant 350 tonnes km 2 a 1 et les glissements et des coulees de debris y contribueraient pour la presque totalite le taux contemporain est probablement perturbe par l utilisation recente du terrain les processus de mouvements de masse semblent etre le mecanisme dominant de transfert de sediments et les contributions provenant des depositions dans les vallees au pleistocene ont diminue de facon significative durant l holocene traduit par la redaction campbell and church 713

sediment and rock strength controls on river incision into bedrock recent theoretical investigations suggest that the rate of river incision into bedrock depends nonlinearly on sediment supply challenging the common assumption that incision rate is simply proportional to stream power our measurements from laboratory abrasion mills support the hypothesis that sediment promotes erosion at low supply rates by providing tools for abrasion but inhibits erosion at high supply rates by burying underlying bedrock beneath transient deposits maximum erosion rates occur at a critical level of coarse grained sediment supply where the bedrock is only partially exposed fine grained sediments provide poor abrasive tools for lowering bedrock river beds because they tend to travel in suspension experiments also reveal that rock resistance to fluvial erosion scales with the square of rock tensile strength our results suggest that spatial and temporal variations in the extent of bedrock exposure provide incising rivers with a previously unrecognized degree of freedom in adjusting to changes in rock uplift rate and climate furthermore we conclude that the grain size distribution of sediment supplied by hillslopes to the channel network is a fundamental control on bedrock channel gradients and topographic relief

retreating ice research in pro glacial areas matters glacier forefields are landscapes in transition from glacial to non glacial conditions this implies intense geomorphic hydrological and ecological dynamics with important on and off site effects this special issue collects 13 papers covering recent research in both sub polar and alpine proglacial environments that focus on i proglacial sediment sources ii proglacial rivers iii proglacial lakes iv ground water and ice and v the development of soil and vegetation in its interplay with morphodynamics advances in mapping surveying and geophysical techniques form the basis for research perspectives related to the historical evolution of proglacial areas the understanding of complex interactions of multiple processes and the effects of continued glacier recession