The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
Laurent Lassabatere - One of the best experts on this subject based on the ideXlab platform.
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characterization of the heterogeneous flow and pollutant transfer in the unsaturated zone in the fluvio Glacial Deposit
Procedia environmental sciences, 2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulojaramillo, D GoutalandAbstract:Abstract Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These basins have been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, i.e. copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
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Characterization of the Heterogeneous Flow and Pollutant Transfer in the Unsaturated Zone in the Fluvio-Glacial Deposit. Four Decades of Progress in Monitoring and Modeling of Processes in the Soil-Plant- Atmosphere System: Applications and Challenge
Procedia Environmental Sciences, 2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulo-jaramillo, D GoutalandAbstract:Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These basins have been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
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Four Decades of Progress in Monitoring and Modeling of Processes in the Soil-Plant- Atmosphere System: Applications and Challenges Characterization of the heterogeneous flow and pollutant transfer in the unsaturated zone in the fluvio-Glacial Deposit
2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulo-jaramillo, D GoutalandAbstract:Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These bhave been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
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Concomitant Zn-Cd and Pb retention in a carbonated fluvio-Glacial Deposit under both static and dynamic conditions
Chemosphere, 2007Co-Authors: Laurent Lassabatere, Lorenzo Spadini, Cécile Delolme, Laureline Fevrier, Rosa Galvez Cloutier, T. WiniarskiAbstract:The chemical and physical processes involved in the retention of 10_2 M Zn, Pb and Cd in a calcareous medium were studied under saturated dynamic (column) and static (batch) conditions. Retention in columns decreased in order: Pb _Cd _ Zn. In the batch experiments, the same order was observed for a contact time of less than 40 h and over, Pb_ Cd > Zn. Stronger Pb retention is in accordance with the lower solubility of Pb carbonates. However, the equality of retained Zn and Cd does not fit the solubility constants of carbonated solids. SEM analysis revealed that heavy metals and calcareous particles are associated. Pb precipitated as individualized ZnCdCa free carbonated crystallites. All the heavy metals were also found to be associated with calcareous particles, without any change in their porosity, pointing to a surface/lattice diffusion-controlled substitution process. Zn and Cd were always found in concomitancy, though Pb fixed separately at the particle circumferences. The Phreeqc 2.12 interactive code was used to model experimental data on the following basis: flow fractionation in the columns, precipitation of Pb as cerrusite linked to kinetically controlled calcite dissolution, and heavy metal sorption onto proton exchanging sites (presumably surface complexation onto a calcite surface). This model simulates exchanges of metals with surface protons, pH buffering and the prevention of early Zn and Cd precipitation. Both modeling and SEM analysis show a probable significant decrease of calcite dissolution along with its contamination with metals.
Thierry Winiarski - One of the best experts on this subject based on the ideXlab platform.
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characterization of the heterogeneous flow and pollutant transfer in the unsaturated zone in the fluvio Glacial Deposit
Procedia environmental sciences, 2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulojaramillo, D GoutalandAbstract:Abstract Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These basins have been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, i.e. copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
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Characterization of the Heterogeneous Flow and Pollutant Transfer in the Unsaturated Zone in the Fluvio-Glacial Deposit. Four Decades of Progress in Monitoring and Modeling of Processes in the Soil-Plant- Atmosphere System: Applications and Challenge
Procedia Environmental Sciences, 2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulo-jaramillo, D GoutalandAbstract:Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These basins have been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
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Four Decades of Progress in Monitoring and Modeling of Processes in the Soil-Plant- Atmosphere System: Applications and Challenges Characterization of the heterogeneous flow and pollutant transfer in the unsaturated zone in the fluvio-Glacial Deposit
2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulo-jaramillo, D GoutalandAbstract:Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These bhave been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
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retention and distribution of three heavy metals in a carbonated soil comparison between batch and unsaturated column studies
Journal of Contaminant Hydrology, 2000Co-Authors: Frederic Plassard, Thierry Winiarski, Michelle PetitramelAbstract:Abstract The uptake of 5×10 −4 mol/l solutions of Cd, Pb and Zn by a fluvio Glacial Deposit with high carbonate content (227 mg/g) was studied in column and batch experiments. The heavy metals were added to soil samples and the retention examined using a speciation scheme with five fractions: exchangeable, acid-soluble, reducible, oxidizable and residual. In batch experiments, the three metal ions were completely bound by the soil, mostly to the acid-soluble fraction: 62% for Cd, 96% Pb and 86% Zn. The exchangeable fraction was of minor importance, with 27% Cd, 4% Pb and 11% Zn. The thermodynamic data suggested that lead and cadmium were mainly associated with carbonate ions while the zinc was found in two forms, zinc hydroxide and zinc carbonate. The influence of initial metal concentration was examined for Cd; an increase in metal concentration led weaker retention. The column experiments showed progressive saturation of the soil, with lead being retained better than cadmium or zinc. The measured retentions of all three metals were lower for columns than in batches. This difference was not explainable by thermodynamic data or by reaction kinetics alone. We believe it is mainly due to preferential flows in column experiments, favouring metal ion elution.
D Goutaland - One of the best experts on this subject based on the ideXlab platform.
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characterization of the heterogeneous flow and pollutant transfer in the unsaturated zone in the fluvio Glacial Deposit
Procedia environmental sciences, 2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulojaramillo, D GoutalandAbstract:Abstract Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These basins have been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, i.e. copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
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Characterization of the Heterogeneous Flow and Pollutant Transfer in the Unsaturated Zone in the Fluvio-Glacial Deposit. Four Decades of Progress in Monitoring and Modeling of Processes in the Soil-Plant- Atmosphere System: Applications and Challenge
Procedia Environmental Sciences, 2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulo-jaramillo, D GoutalandAbstract:Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These basins have been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
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Four Decades of Progress in Monitoring and Modeling of Processes in the Soil-Plant- Atmosphere System: Applications and Challenges Characterization of the heterogeneous flow and pollutant transfer in the unsaturated zone in the fluvio-Glacial Deposit
2013Co-Authors: Thierry Winiarski, Laurent Lassabatere, Rafael Angulo-jaramillo, D GoutalandAbstract:Infiltration basins are part of the best management practices. They are aimed at infiltrating stormwater to prevent additional collection and treatment through rainwater systems. In the suburbs of Lyon (France), many of these infiltration basins were built over fluvio-Glacial Deposit. These bhave been the subject of research programs on vadose zone flow and fate of pollutants. This study focuses on the impact of the heterogeneity of the fluvio-Glacial Deposit on both flow pattern and solute transfer. A proper geological and sedimentological description is first proposed to characterize the efficient water transfer properties of the fluvio-Glacial Deposit at the work scale (1 ha). The local geological and sedimentological architecture of the Deposit and its lithofacies were investigated locally through trenches using both particle size analysis and sedimentological approach. This information was extended to the whole work by combining several geophysical techniques, i.e. GPR, electric resistivity and seismic refraction tomography (data not shown). Then water infiltration experiments were performed on each lithofacies to derive the hydrodynamic properties through BEST algorithm (Beerkan estimation of Soil Transfer properties), leading to the corresponding hydrofacies. In addition, soil-column and batch experiments were performed to estimate hydrodispersive parameters by tracer experiments and the geochemical properties of lithofacies for a model pollutant, copper (Cu). All these data were implemented into Hydrus to model flow and solute transfer through a 2D soil profile with a precise description of the hydrofacies at the basin scale (flow domain 14x2 m2). The results are highly relevant because they emphasize different types of preferential flow due to either the presence of capillary barriers, drainage layers or pipe flow, which may be responsible for the enhancement of pollutant transfer. In particular, they show that sand lenses may play an important role whereas unconnected gravels may have insignificant effect on flow. This methodology may help in understanding the mechanisms which that are responsible for preferential solute transfer. A sensitivity analysis combining the distribution of lithofacies, the soil initial water content and unsaturated hydraulic properties allows bettering understanding the development of preferential flows across the vadose zone underneath the basin. This data is of great interest in terms of the optimization of basin infiltration monitoring.
Tim Davies - One of the best experts on this subject based on the ideXlab platform.
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the extremely long runout komansu rock avalanche in the trans alai range pamir mountains southern kyrgyzstan
Landslides, 2015Co-Authors: Tom R Robinson, Natalya V. Reznichenko, Tim Davies, Gregory P De PascaleAbstract:Massive rock avalanches form some of the largest landslide Deposits on Earth and are major geohazards in high-relief mountains. This work reinterprets a previously reported Glacial Deposit in the Alai Valley of Kyrgyzstan as the result of an extremely long-runout, probably coseismic, rock avalanche from the Komansu River catchment. Total runout of the rock avalanche is ~28 km, making it one of the longest-runout subaerial non-volcanic rock avalanches thus far identified on Earth. This runout length appears to require a rock volume of ~20 km3; however, the likely source zone in the Trans Alai range likely contained just ~4 km3 of rock, and presently, the Deposit has a volume of only 3–5 km3; a pure rock avalanche volume of >10 km3 is therefore impossible, so the event was much more mobile than most non-volcanic rock avalanches. Explaining this exceptional mobility is crucial for present-day hazard analysis. There is unequivocal sedimentary evidence for intense basal fragmentation, and the Deposit in the Alai Valley has prominent hummocks; these indicate a rock avalanche rather than a rock-ice avalanche origin. The event occurred 5,000–11,000 yr B.P., after the region’s glaciers had begun retreating, implying that supraGlacial runout was limited. Current volume—runout relationships suggest a maximum runout of ~10 km for a 4-km3 rock avalanche. Volcanic debris avalanches, however, are more mobile than non-volcanic rock avalanches due to their much higher source water content; a rock avalanche containing a similarly high water content would require a volume of about 8 km3 to explain the extreme runout of the Komansu event. Rock and debris avalanches can entrain large amounts of material during runout, with some doubling their initial volume. The best current explanation of the Komansu rock avalanche thus involves an initial failure of ~4 km3 of rock debris, with high water content probably deriving from large glaciers on the edifice that subsequently entrained ~4 km3 of valley material together with further Glacial ice, resulting in a total runout of 28 km. It is as yet unclear whether Glacial retreat has rendered a present-day repetition of such an event impossible.
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evidence for a rock avalanche origin for the hillocks moraine otago new zealand
Geomorphology, 2011Co-Authors: Samuel T Mccoll, Tim DaviesAbstract:Abstract A landform in Otago, New Zealand, previously interpreted as a Glacial Deposit, has been investigated, described and reinterpreted as a rock avalanche Deposit. ‘The Hillocks’ is a conspicuous cluster of small conical hills on the Dart River floodplain. The landform is protected under a local bylaw because of its identification as an outstanding example of a Glacial kame Deposit. However, the geological and geomorphological setting, and the Deposit morphology, sedimentology and lithology, suggest that it was formed by a large (c. 22.5 × 10 6 m 3 ) rock avalanche subsequent to Glacial retreat, and that the Deposit temporarily dammed the Dart River valley. Relative age dating evidence suggests that it is at least several hundred years old but younger than ca 7500 B.P. This work highlights the problem of paleoclimatic reconstructions using ‘moraines’ as indicators of regional climate events. Despite similarities in form and, in some cases, sedimentology, by applying an understanding of landslide initiation, runout and Depositional process, we demonstrate that it is possible to distinguish the Deposits produced by landslides from those produced by Glacial Deposition.
Gregory P De Pascale - One of the best experts on this subject based on the ideXlab platform.
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the extremely long runout komansu rock avalanche in the trans alai range pamir mountains southern kyrgyzstan
Landslides, 2015Co-Authors: Tom R Robinson, Natalya V. Reznichenko, Tim Davies, Gregory P De PascaleAbstract:Massive rock avalanches form some of the largest landslide Deposits on Earth and are major geohazards in high-relief mountains. This work reinterprets a previously reported Glacial Deposit in the Alai Valley of Kyrgyzstan as the result of an extremely long-runout, probably coseismic, rock avalanche from the Komansu River catchment. Total runout of the rock avalanche is ~28 km, making it one of the longest-runout subaerial non-volcanic rock avalanches thus far identified on Earth. This runout length appears to require a rock volume of ~20 km3; however, the likely source zone in the Trans Alai range likely contained just ~4 km3 of rock, and presently, the Deposit has a volume of only 3–5 km3; a pure rock avalanche volume of >10 km3 is therefore impossible, so the event was much more mobile than most non-volcanic rock avalanches. Explaining this exceptional mobility is crucial for present-day hazard analysis. There is unequivocal sedimentary evidence for intense basal fragmentation, and the Deposit in the Alai Valley has prominent hummocks; these indicate a rock avalanche rather than a rock-ice avalanche origin. The event occurred 5,000–11,000 yr B.P., after the region’s glaciers had begun retreating, implying that supraGlacial runout was limited. Current volume—runout relationships suggest a maximum runout of ~10 km for a 4-km3 rock avalanche. Volcanic debris avalanches, however, are more mobile than non-volcanic rock avalanches due to their much higher source water content; a rock avalanche containing a similarly high water content would require a volume of about 8 km3 to explain the extreme runout of the Komansu event. Rock and debris avalanches can entrain large amounts of material during runout, with some doubling their initial volume. The best current explanation of the Komansu rock avalanche thus involves an initial failure of ~4 km3 of rock debris, with high water content probably deriving from large glaciers on the edifice that subsequently entrained ~4 km3 of valley material together with further Glacial ice, resulting in a total runout of 28 km. It is as yet unclear whether Glacial retreat has rendered a present-day repetition of such an event impossible.