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  • The formation of supraglacial debris covers by primary dispersal from transverse englacial debris bands
  • Alps (The) ; Debris cover ; Glacial ablation ; Glacier ; Glaciology ; Italy ; Model
  • Glaciological controls on debris cover formation are investigated from the perspective of primary dispersal of supraglacial debris across a melting ice surface. This involves the migration of angled debris septa outcrops across a melting, thinning
  • glacier ablation zone. First, simple geometric relations between englacial septa and the supraglacial debris load are outlined to elucidate the role of glaciological variables (gradient, ice motion, ablation, rate of glacier thinning) on debris cover
  • formation. Second, these relations are quantified at a small alpine glacier (Glacier d'Estelette, Italian Alps) to present an explanatory model of why certain parts of the glacier are becoming more rapidly debris-covered than others. Finally
  • , the implications of the model for the debris-cover transition are discussed in relation to the sensitivity of different glacier terminus types to debris-cover formation.
  • Wash erosion on a debris covered slope in a semi-arid climate
  • Ablation spécifique ; Afrique du Sud ; Domaine aride ; Domaine semi-aride ; Eboulis ; Erosion des sols ; Erosion par ruissellement ; Expérimentation de terrain ; Géographie physique ; Orange Free State ; Versant ; Versant de débris
  • Field experimentation on a steep debris slope. The rate of denudation in terms of rock density was found to be 17.8 mm per thousand years. This rather low figure results from several factors : e.g. good canopy and basal cover of vegetation, cover
  • by rock debris, very little disturbance by man or grazing animals and the lack of available material suitable for transport.
  • A rock glacier/debris-covered glacier system at Galena Creek, Absaroka Mountains, Wyoming
  • At Galena Creek, the ice/debris system has alternated between rock glacier and debris-covered glacier modes due to changes in the size of the accumulation area. These results have important implications for paleoclimatic studies of the ice
  • Estimate of ablation rate of glacier ice under a supraglacial debris layer
  • Ablation glaciaire ; Débris supraglaciaires ; Eau de fonte ; Glacier ; Haute montagne ; Himalaya ; LANDSAT ; Méthodologie ; Népal ; Température de surface ; Télédétection
  • The ablation rate under a debris layer is very difficult to measure directly at debris-covered glaciers, because the surface is highly heterogeneous, and the ablation rate varies tremendously from place to place. This paper describes previous works
  • on the ablation process, and a test result of a proposed method to estimate the ablation rate under a debris layer is presented for the Lirung Glacier in Langtang Valley, Nepal Himalaya.
  • Properties of natural supraglacial debris in relation to modelling sub-debris ice ablation
  • Albedo ; Debris cover ; Glacial ablation ; Glacial features ; Glacier ; Glacier mass balance ; Himalaya ; Model ; Nepal ; Seasonal variability ; Thermal conductivity
  • require consideration in annual or multi-annual distributed modelling of debris-covered glacier surface energy and mass balance.
  • The AA. report measurements of vertical temperature profiles in debris on the Ngozumpa glacier in the Khumbu Himal region,Nepal, that show : 1) conductive processes dominate during the ablation season in matrix-supported diamict; 2) ventilation may
  • be possible in coarse surface layers; 3) phase changes associated with seasonal change have a marked effect on the effective thermal diffusivity of the debris. Effective thermal conductivity determined from vertical temperature profiles in the debris
  • is generally higher in summer than in winter, but values depend on the volume and phase of water in the debris. Surface albedo can vary widely over small spatial scales, as does the debris thickness. The findings from Ngozumpa glacier indicate
  • that the probability distribution of debris thickness changes from positively skewed in the upper glacier towards a more normal distribution nearer the terminus. These observations highlight aspects of spatial and temporal variability in supraglacial debris that may
  • Debris-covered glaciers and rock glaciers in the Nanga Parbat Himalaya, Pakistan
  • The origin and mobilization of the extensive debris cover associated with the glaciers of the Nanga Parbat Himalaya is complex. The AA. propose a mechanism by which glaciers can form rock glaciers through inefficiency of sediment transfer from
  • A discussion regarding weathering in the western Cape mountains, South Africa : implications for pleistocene cryoclastic debris production
  • The extensive angular Pleistocene debris covers of the western Cape have been attributed to cryoclastic origin. However, evidence of chemical weathering and lichen growth is presented suggesting further research is necessary. - (AJC)
  • La trasformazione dei ghiacciai bianche (debris free glaciers) in ghiacciai neri (debris covered glaciers) per un approccio didattico applicato
  • La transformation des glaciers blancs (sans débris) en des glaciers noirs (avec débris) au travers d'une approche didactique appliquée
  • The Alpine landscape is changing in relation to global warming. Glaciers are progressively covering their tongues by a layer of debris protecting them from the ablation processes. The “clean” glacier changes into a debris covered glaciers, passing
  • Distribution of large woody debris along the outer bend of meanders in the Ain River, France
  • Ain ; Cours d'eau ; Débris ligneux ; Forêt ; France ; Géométrie hydraulique ; Méandre ; Piedmont ; Plaine d'inondation ; Statistique ; Végétation ripicole
  • The distribution of large woody debris (LWD) was studied along the concave outer bend of 3 meanders in the Ain River. The Ain River is a sixth-order channel dominated by a gravel-cobble bed substrate that meanders through a floodplain covered
  • Thermal properties of a supraglacial debris layer with respect to lithology and grain size
  • Ablation glaciaire ; Alpes ; Autriche ; Conductivité thermique ; Débris ; Eau de fonte ; Glacier ; Granulométrie ; Géophysique ; Humidité ; Lithologie ; Parcelle expérimentale
  • Alps (The) ; Austria ; Debris ; Experiment plot ; Geophysics ; Glacial ablation ; Glacier ; Grain size distribution ; Lithology ; Meltwater ; Moisture ; Thermal conductivity
  • The ablation experiments with artificial debris cover were performed on the middle tongue of Vernagtferner, a temperate glacier in the Ötztal Alps, Austria. Ten test plots were established with different debris grain sizes and debris thicknesses
  • layer thicknesses of the local mica schist. However, the analysis of thermal diffusivities demonstrated that the vertical moisture distribution of the debris cover must be taken into consideration, with the diffusivity values being significantly lower
  • consisting of different natural material. For each plot, values of thermal conductivity were determined. The observations revealed a clear dependence of the sub-debris ice melt on the layer thickness, grain size, porosity and moisture content. For the sand
  • The response of partially debris-covered valley glaciers to climate change : the example of the Pasterze Glacier (Austria) in the period 1964 to 2006
  • Alpes ; Années 1964-2006 ; Autriche ; Bilan de masse ; Changement climatique ; Climat ; Couverture de débris ; Distribution spatiale ; Glacier ; Modèle numérique de terrain ; Moraine ; Vallée glaciaire
  • This study investigates the response to recent climate change of the partially debris-covered Pasterze Glacier, the largest glacier of the Eastern Alps. The study concentrates on behaviour differences between the adjacent debris-covered and clean
  • temperatures. The findings clearly underline the importance of supra-glacial debris on mass balance and glacier tongue morphology.
  • Influence of supraglacial debris on summer ablation and mass balance in the 24K Glacier, southeast Tibetan Plateau
  • Air temperature ; China ; Debris cover ; Glacial ablation ; Glacier ; Glacier mass balance ; Impact ; Model ; Summer ; Tibet
  • Many temperate glaciers in the southeast Tibetan Plateau are covered by supraglacial debris in the ablation area. To evaluate the effect of such debris on summer ablation and mass balance, the surface ablation on the 24K Glacier was measured
  • in the summer of 2008. Mean ablation rates varied from 10 to 52 mm/day, strongly correlated to debris thickness. Synchronous observations of air temperature allowed application of a simple degree-day model to calculate ablation rates. Maximum values of both
  • ablation rate and degree-day factors appeared in the middle area of the glacier where the debris layer thickness was about 1 cm. The simulated daily ablation obtained from the degree-day approach showed that the debris layers significantly affected
  • Debris-flow magnitude-frequency relationships for mountainous regions of Central and Northwest Europe
  • Debris flow ; Europe ; Human impact ; Land use ; Mountain ; Natural hazards ; Northwestern Europe ; Plant cover ; Precipitation ; Slope dynamics ; Statistics
  • From the viewpoint of hazard assessment the magnitude-frequency characteristics is an essential element of the debris-flow process. For this study, published data specifying both magnitude and frequency were used for the Alps, the Tatra Mountains
  • patterns and debris availability play a prominent part.
  • Geomorphic evolution of debris fans in the Du Toit's Kloof, Western Cape mountains
  • Two debris fans in Du Toit's Kloof are investigated by means of geomorphological mapping and relative-age dating (Schmidt hammer, lichen cover and weathering rinds) of their deposits. The data provide important new insights into footslope dynamics
  • Air temperature ; Climate ; Debris cover ; Digital elevation model ; Glacial ablation ; Glacial features ; Meltwater ; Moraine ; New Zealand ; Sandur ; South Island
  • To evaluate the effects of varying debris-cover and climate on ice-melt in a maritime mid-latitude setting, an 11-day ablation stake study was undertaken on ice-cored moraine at Fox Glacier. Ablation rates varied with enhancement of melt-rate under
  • thin debris-covers. Air temperature from nearby Franz Josef Glacier allowed for a simple degree-day approach to ablation calculations, with regression relationships indicating air temperature is the key climatic control on melt. Digital elevation models
  • produced from topographic surveys of the ice-cored moraine over the following months indicated that ablation rates progressively decreased over time, probably due to melt-out of englacial debris increasing debris-cover thickness. The morphology
  • Monitoring sediment source areas in a debris-flow catchment using terrestrial laser scanning
  • Alpes ; Balayage laser terrestre ; Bassin-versant ; Coulée de débris ; Friuli-Venezia Giulia ; Italie ; Modèle numérique de terrain ; Montagne ; Moscardo ; Méthodologie ; Surveillance ; Végétation
  • Alps (The) ; Debris flow ; Digital elevation model ; Friuli-Venezia Giulia ; Italy ; Methodology ; Monitoring ; Mountain ; Terrestrial laser scanning ; Vegetation ; Watershed
  • into account the disturbance caused by the vegetation cover on the DEM accuracy is proposed. The results of volumetric budgets of the surveyed sediment source areas derived from the DoD analysis were compared with debris-flow volumes estimated from flow stage
  • Geomorphic changes caused by 3 debris-flow events in a small mountain catchment (Moscardo Torrent, Eastern Italian Alps) were investigated by means of multitemporal terrestrial laser scanning (TLS) surveys over 3 areas exposed to debris-flow
  • measurements at the instrumented channel reach, underlining advantages and limitations of TLS surveys over morphologically complex areas such as debris-flow catchments.
  • Topographic control of periglacial slope covers, Ślęża Massif, southwest Poland : a statistical approach
  • The slopes of Mt Ślęża, southwest Poland, are covered by debris covers that consist of gabbro blocks. Six classes of slope covers have been distinguished based on the concentration of blocks. A map of slope covers has been digitized
  • Proglacial debris flows in Popocatepetl north face and their relation to 1995 eruption
  • Glacier ; Meltwater ; Mexico ; Mudflow ; Sedimentary structure ; Snow cover ; Volcanic ash ; Volcanic eruption ; Volcanism ; Volcano
  • Cet article analyse la structure sédimentaire et l'origine des coulées de débris proglaciaires sur le flanc nord du Popocatepetl, ainsi que leur relation avec l'éruption d'avril 1995. Les investigations ont montré que les coulées de débris ont pris
  • Sensitivity of frost weathering and aeolian deposition during genesis of Late Quaternary periglacial slope covers on calcareous rocks of a Muschelkalk landscape, eastern Thuringian Basin, Germany
  • weathering rates within the debris. The AA. assume that the deposition of loess sediments might be sensitive to both properties and patterns of debris cover and to the amount of pre-existing Braunlehm that resulted from limestone dissolution processes. Soil
  • The lithological and petrological properties of calcareous rock types are reflected by remarkably different structure, thickness and clast properties of frost shattered debris within the investigated Muschelkalk landscape as well as in chemical
  • moisture conditions and vegetation cover might have been as crucial factors for loess distribution as luff-/lee-effects of the regional wind system or karst surface morphology. Considering the ecological consequences implied by the structure
  • and heterogeneity of periglacial loose rock cover, limestone landscapes in general seem to be vulnerable to degradation processes.
  • Cirque ; Freezing ; Japan ; Mountain ; Rockfall ; Seasonal variation ; Snow cover ; Temperature ; Thawing ; Weathering
  • This paper describes observations of rockfall activity in Hosozawa Cirque in the Japanese Alps, from 1984 to 1998. The period includes intensive observations of both rockfalls and rock temperatures for 3 years (1993-1995). Rock debris transported
  • onto snow surfaces was measured during seasonal thawing periods. Discussion is focused on the mechanism of rockfall generation and controls of the dimension of rockfall debris.