Analysis of the shape sedimentary particles can provide information about their transport history and aid facies differentiation characterization depositional environments. Triangular (Sneed Folk) diagrams, employing ratios three orthogonal particle axes, have been advocated as most appropriate method for unbiased presentation primary data. A spreadsheet production these diagrams is described. Clast data-sets from a range environments are presented using this method. An alternative use...

The spatial and temporal resolution of surface grain‐size characterization is constrained by the limitations traditional measurement techniques. In this paper we present an extremely rapid image‐processing‐based procedure for exposed fluvial gravels other coarse‐grained sediments, defining steps required to minimize errors in derived distribution. This differs significantly from those used previously. It based around a robust object‐detection algorithm that produces excellent results on...

Recent years have seen increased interest in automated methods, utilizing photographs collected with a handheld digital camera, for determining the grain size distribution of coarse river sediments. Such methods are as precise traditional field and considerable time cost advantages. Nevertheless, several unresolved issues pertaining to their deployment remain be addressed. Using data sets from seven gravel bed rivers, this paper examines four key issues: (1) minimum area required obtain...

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. work is of interest because glacial landforms developed Svalbard used as an analogue for Pleistocene mid-latitude glaciation. Ground penetrating radar was investigate subsurface characteristics moraines. To determine surface change, LiDAR topographic data set (obtained 2003)...

Continuity of sediment transfer through glacial systems is essential to maintain subglacial bedrock erosion, yet at temperate glaciers with overdeepened beds, where fluvial transport should be greatly limited by adverse slopes, remains poorly understood. Complex multiple processes in has been indicated the presence large frontal moraine systems, supraglacial debris mixed origin, thick basal ice sequences, and englacial thrusts eskers. At Svínafellsjökull, comprising decimetre-thick...

Abstract A passive seismology experiment was conducted across the main overdeepening of Storglaciären in Tarfala valley, northern Sweden, to investigate spatial and temporal distribution basal microseismic waveforms relation known dynamics this small polythermal sub-arctic glacier. The high ablation rate made it difficult keep geophones buried well coupled glacier during reduced number days good-quality data collection. characterization typical atypical showed that dominant were from...

A surficial geology and geomorphology map of the forelands Sandfellsjökull Oldufellsjökull piedmont lobes east Mýrdalsjökull ice cap is used to characterise historical modern landscape imprint in a glacial landsystems context. This serves as analogue for palaeoglaciological reconstructions systems that operated outlet contrasting dynamics, but subtle variability process-form regimes encoded geomorphology. The two reflect significantly different regimes, hence glacier despite fact they are...

Information about the grain-size distribution of surface layer sediment exposed on riverbeds is often critical in studies fluvial hydraulics, geomorphology, and ecology. A variety sampling analysis techniques are common usage that produce distributions not directly comparable. This paper seeks to explore appropriate conversions between different types methods. particularly timely light increasingly widespread use automatic semiautomatic image-based measurement methods, comparability which...

Abstract Dispersed facies basal ice – massive (i.e. structureless) with dispersed debris aggregates is present at the margins of many glaciers and, as a product internal glacial processes, has potential to provide important information about mechanisms glacier flow and nature subglacial environment. The origin poorly understood, several hypotheses having been advanced for its formation, there disagreement whether it largely sedimentary or tectonic feature. We test these established temperate...

Abstract The Younger Dryas ( c. 11-10 ka bp ) moraine-mound complex (‘hummocky moraine’) in the historically important site of Cwm Idwal, North Wales, has previously been interpreted using periglacial, subglacial, ice-marginal and englacial models. In this paper morphology sedimentology these landforms is described competing hypotheses tested against evidence. It demonstrated that an thrusting model, developed for polythermal glaciers Svalbard, best fits available Thrusting probably resulted...

Abstract Digital photogrammetry has been used to develop and test an artificial river bed moulding casting system, which allows the pebbles within a coarse‐grain be recreated for hydraulic research in laboratory flow channel or flume. Imagery of both original streambed cast facsimile was acquired using non‐metric Kodak DCS460 digital camera elevation models orthophotographs were derived compared assess accuracy system. These comparative tests proved critical modifying developing Additional...

Despite a long history of glaciological research, the palaeo‐environmental significance moraine systems in Kebnekaise Mountains, Sweden, has remained uncertain. These landforms offer potential to elucidate glacier response prior period direct monitoring and provide an insight into ice‐marginal processes operating at polythermal valley glaciers. This study set out test existing interpretations Scandinavian moraines, which invoke ice stagnation, pushing, stacking/dumping push‐deformation as...

RÉSUMÉOn s'est servi d'images prises par satellite Landsat muni d'un SMB et capteur TM le radar du Seasat en vue de la préparation d'une carte des linéaments qui couvre une superficie plus 850 000 km2, soit l'ensemble plaines l'Ouest Alberta Saskatchewan certaines parties Colombie-Britannique Territoires Nord-Ouest. Deux ensembles linéaments, à orientation nord-est autre nord-ouest, se rencontrent partout dans région. Ils représentent vraisemblablement failles d'extension presque verticales...