scholarly journals Rock glacier and protalus rampart inventory in Las Salinas river basin, Central Andes of Argentina

2021 ◽  
Author(s):  
Ana Paula Forte ◽  
Cristian Daniel Villarroel ◽  
María Yanina Esper Angillieri
Keyword(s):  
River Basin ◽  
Central Andes ◽  
Slope Aspect ◽  
Optical Remote Sensing ◽  
Rock Glacier ◽  
Study Region ◽  
Hydrological System ◽  
Rock Glaciers ◽  
Salinas River ◽  
The Relationship

This paper presents a detailed rock glacier and protalus rampart inventory from Las Salinas river basin, an arid subtropical mountain hydrological system (between 31°02’ and 31°22’ S latitude) located in the northern sector of the Central Andes of Argentina, where permafrost and cryogenic processes prevail. The inventory is based on a geomorphological characterization by means of optical remote sensing and field description data. The study region covers 630 km2, with 3.25% of the area containing 405±8.2 rock glaciers and protalus ramparts in total, of which 231±2.5 are considered protalus rampart and 49±2 are considered active, 61±1 inactive and 64±3 fossil rock glaciers. Frequency ratio and logistic regression were used as statistical methods to determine the relationship between the distribution of these periglacial landforms and different geological, morphometric and climatic variables as elevation, potential incoming solar radiation, slope, aspect and lithology. Results show that elevation, lithology, and aspect are the most influencing factors for the occurrence of active rock glaciers. According to rock glaciers and protalus ramparts distribution, the permafrost occurrence probability is above 3690 m a.s.l. (current and high periglacial environment). However, some inactive rock glaciers and protalus rampart were found below this elevation, thus between 3300 and 3690 m a.s.l. the landscapes are dominated by an unstable periglacial environment.

scholarly journals Impact of natural parameters on rock glacier development and conservation in subtropical mountain ranges. Northern sector of the Argentine Central Andes

2016 ◽  
Author(s):  
Ana P. Forte ◽  
Cristian D. Villarroel ◽  
María Y. Esper Angillieri
Keyword(s):  
Statistical Analysis ◽  
Solar Radiation ◽  
Ratio Method ◽  
High Mountain ◽  
Special Importance ◽  
Optical Remote Sensing ◽  
Rock Glacier ◽  
Study Region ◽  
Significant Difference ◽  
Rock Glaciers

Abstract. This paper presents a detailed rock glacier inventory used in determining how the various natural parameters affect a mountain periglacial environment. This study was undertaken in a northernmost sector of the central Argentine Andes, in an area stretching between 31°02' and 31°22' S latitude. This is a high and arid subtropical region where permafrost and cryogenic processes are predominant, featuring as well as a large number of rock glaciers and associated periglacial landforms. Rock glaciers inventory was based on geomorphological characterization with optical remote sensing data and field description information. The study region covers 630 km2, with 3,25 % of this area showing 402 rock glaciers and protalus rampart features. In total, 172 rock glaciers have been identified, 48 of which are considered active. In such a sector, the protalus rampart range shows the largest landform occurrences, though fossil and inactive rock glaciers are usually larger and are developed over a larger attitudinal distribution. Based on previous studies, we have considered that the study of active rock glaciers is an effective approach to assess the current state of periglacial environment evolution. Therefore, we analysed their spatial distribution and their relationship through different variables, by resorting to statistical analysis and a frequency ratio method. The chosen natural parameters were: Lithology, Elevation, Latitude and Longitude, Aspect, Slope and Annual Potential Solar Incoming Radiation. Analytical results have demonstrated that active rock glaciers landforms lie above 3.600 m a.s.l. elevations, on 11° to 28° slopes with predominating south facing aspect and relatively low solar radiation. The statistical analysis shows that elevation, lithology and aspect are the most influencing factors for current periglacial environment development while rock glacier conservation is mainly controlled by lithology. On the study area,the annual potential solar radiation show high values but there is not any significant difference between landform and, therefore, it is scarcely influential. The research is carried out over a high mountain area where poor accessibility hindered the chances for obtaining systematic data on weather and environment. A simple and low coast methodology was used to analyse an area where no studies on rock glacier distribution had been made before. This information gains special importance because Argentina has recently instituted a national law for glacial and periglacial environment protection and conservation. Therefore, this research and its results may contribute a significant step toward knowing the number, features and distribution of rock glacier bodies lying in a scarcely studied region.

scholarly journals Pluri-decadal (1955–2014) evolution of glacier–rock glacier transitional landforms in the central Andes of Chile (30–33° S)

2016 ◽  
Author(s):  
S. Monnier ◽  
C. Kinnard
Keyword(s):  
Central Andes ◽  
Vertical Surface ◽  
Horizontal Surface ◽  
Rock Glacier ◽  
Surface Displacements ◽  
Short Time Span ◽  
Digital Elevation ◽  
Vertical Displacements ◽  
Rock Glaciers ◽  
Elevation Model

Abstract. This study deals with relationships between debris-covered glaciers and rock glaciers in the central Andes of Chile. Three glacier–rock glacier transitional landforms are investigated over the last decades in order to highlight and question the significance of their landscape evolution and dynamics. We use series of historical air photos and Geoeye satellite images together with common remote sensing operations including imagery orthorectification, digital elevation model generation, and cross-correlation image matching. At each site, the following items were monitored: rock glacier morphology, thermokarst area, horizontal surface displacements and vertical surface displacements. The evolution of the landforms is remarkable given the short time span of the study, with horizontal surface displacements up to more than 3 m yr−1 and vertical displacements up to more than ±1 m yr−1. The landforms studied reveal different evolutional significance: (i) overlap of glacier and rock glacier development; (ii) glacier–rock glacier transformation; (iii) glacier–rock glacier collision. Insights are gained for the second case: the transformation may take place by the division and mixing of the buried ice body into distinct flow lobes and/or the apparent upward progression of the rock glacier morphology by the successive incorporation of debris-covered glacier patches.

scholarly journals Inferring the destabilization susceptibility of mountain permafrost in the French Alps using an inventory of destabilized rock glaciers

2018 ◽  
Author(s):  
Marco Marcer ◽  
Charlie Serrano ◽  
Alexander Brenning ◽  
Xavier Bodin ◽  
Jason Goetz ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Regional Scale ◽  
Susceptibility Map ◽  
Rock Glacier ◽  
Study Region ◽  
Support Tool ◽  
French Alps ◽  
Terrain Attributes ◽  
Rock Glaciers ◽  
Deformation Patterns

Abstract. Knowing the extent of degrading permafrost is a key issue in the context of emerging risks linked to climate change. In the present study we propose a methodology to estimate the spatial distribution of this phenomenon, focusing on the French Alps. At first, using recent orthoimages (2000 to 2013) covering the study region, we mapped the geomorphological features that can be typically found in cases of rock glacier destabilization (e.g. crevasses and scarps). This database was then used as support tool to rate rock glaciers destabilization. The destabilization rating was assigned also taking into account the surface deformation patterns of the rock glacier, observable by comparing the orthoimages. The destabilization rating served as database to model the occurrence of destabilization in relation to terrain attributes and to predict the susceptibility to destabilization at the regional scale. Potential destabilization could be observed in 58 rock glaciers, i.e. 12  of the total active rock glaciers in the region. Potentially destabilized rock glaciers were found to be more prone to strong acceleration than stable rock glaciers within the period 2000–2013. Modelling the occurrence of destabilization suggested that this phenomenon is more likely to occur in elevations around the 0 °C isotherm (2700–2900 m.s.l.), on north-exposed, steep (up to 30°) and flat to slightly convex topographies. Model performances were good (AUROC: 0.76) and the susceptibility map reproduced well the observable patterns. About 3 km2 of creeping permafrost, i.e. 10 % of the surface occupied by active rock glaciers, had a high susceptibility to destabilization. Only half of this surface is currently showing destabilization evidence, suggesting that a significant amount of rock glaciers are candidates for future destabilization.

Relationships between glacier and rock glacier in the Maritime Alps, Schiantala Valley, Italy

2007 ◽  
Vol 68 (3) ◽  
pp. 353-363 ◽  
Author(s):  
Adriano Ribolini ◽  
Alessandro Chelli ◽  
Mauro Guglielmin ◽  
Marta Pappalardo
Keyword(s):  
Little Ice Age ◽  
Geophysical Methods ◽  
Ice Crystals ◽  
Ice Age ◽  
Ice Formation ◽  
Dc Resistivity ◽  
Rock Glacier ◽  
Maritime Alps ◽  
Rock Glaciers ◽  
The Relationship

AbstractIn the Schiantala Valley of the Maritime Alps, the relationship between a till-like body and a contiguous rock glacier has been analyzed using geomorphologic, geoelectric and ice-petrographic methodologies. DC resistivity tomographies undertaken in the till and in the rock glacier show the presence of buried massive ice and ice-rich sediments, respectively. Ice samples from a massive ice outcrop show spherical gas inclusions and equidimensional ice crystals that are randomly orientated, confirming the typical petrographic characteristics of sedimentary ice. The rock glacier formation began after a phase of glacier expansion about 2550"50 14C yr BP. Further ice advance during the Little Ice Age (LIA) overrode the rock glacier root and caused partial shrinkage of the pre-existing permafrost. Finally, during the 19th and 20th centuries, the glacial surface became totally debris covered. Geomorphological and geophysical methods combined with analyses of ice structure and fabric can effectively interpret the genesis of landforms in an environment where glaciers and permafrost interact. Ice petrography proved especially useful for differentiating ice of past glaciers versus ice formed under permafrost conditions. These two mechanisms of ice formation are common in the Maritime Alps where many sites of modern rock glaciers were formerly occupied by LIA glaciers.

scholarly journals Towards accurate quantification of ice content in permafrost of the Central Andes, part I: geophysics-based estimates from three different regions

2021 ◽  
Author(s):  
Christin Hilbich ◽  
Christian Hauck ◽  
Coline Mollaret ◽  
Pablo Wainstein ◽  
Lukas U. Arenson
Keyword(s):  
Remote Sensing ◽  
Hydrological Cycle ◽  
Field Measurements ◽  
Central Andes ◽  
Rock Glacier ◽  
Ground Ice ◽  
Catchment Scale ◽  
Refraction Seismic ◽  
Rock Glaciers ◽  
Ice Content

Abstract. In view of the increasing water scarcity in the Central Andes in response to ongoing climate change, the significance of permafrost occurrences for the hydrological cycle is currently being discussed in a controversial way. The lack of comprehensive field measurements and quantitative data on the local variability of internal structure and ground ice content further enhances the situation. We present field-based data from six extensive geophysical campaigns completed since 2016 in three different high-altitude regions of the Central Andes of Chile and Argentina (28 to 32° S). Our data cover various permafrost landforms ranging from ice-poor bedrock to ice-rich rock glaciers and are complemented by ground truthing information from boreholes and numerous test pits near the geophysical profiles. In addition to determining the thickness of the potential ice-rich layers from the individual profiles, we also use the quantitative 4-phase model to estimate the volumetric ground ice content in representative zones of the geophysical profiles. The analysis of 52 geoelectrical and 24 refraction seismic profiles within this study confirmed that ice-rich permafrost is not restricted to rock glaciers, but is also observed in non-rock-glacier permafrost slopes in the form of interstitial ice as well as layers with excess ice, resulting in substantial ice contents. Consequently, non-rock glacier permafrost landforms, whose role for local hydrology has so far not been considered in remote-sensing based approaches, may be similarly relevant in terms of ground ice content on a catchment scale and should not be ignored when quantifying the potential hydrological significance of permafrost. We state that geophysics-based estimates on ground ice content allow for more accurate assessments than purely remote-sensing-based approaches. The geophysical data can then be further used in upscaling studies to the catchment scale in order to reliably estimate the hydrological significance of permafrost within a catchment.

scholarly journals Inventory, motion and acceleration of rock glaciers in Ile Alatau and Kungöy Ala-Too, northern Tien Shan, since the 1950s

2020 ◽  
Author(s):  
Andreas Kääb ◽  
Tazio Strozzi ◽  
Tobias Bolch ◽  
Rafael Caduff ◽  
Håkon Trefall ◽  
...  
Keyword(s):  
Sediment Transport ◽  
High Resolution ◽  
Tien Shan ◽  
Spatial And Temporal Variability ◽  
European Alps ◽  
Rock Glacier ◽  
Study Region ◽  
Rock Glaciers ◽  
The 1950S ◽  
Northern Tien Shan

Abstract. Spatio-temporal patterns of rock glacier creep have rarely been studied outside the densely populated European Alps. This study investigates the spatial and temporal variability of rock glacier motion in the Ile Alatau and Kungöy Ala-Too mountain ranges, northern Tien Shan. Over the study region of more than 3000 km2, an inventory of slope movements is constructed using a large number of radar interferograms and high-resolution optical imagery. The inventory includes more than 900 landforms, of which around 550 are interpreted as rock glaciers. Out of the active rock glaciers, 45 are characterised by a rate of motion exceeding 1 m/a. From these fast rock glaciers we select six and study them in more detail (Gorodetzky, Morenny, Archaly, Ordzhonikidze, Karakoram and Kugalan Tash rock glaciers) using offset tracking between airphotos, and historical and modern very high resolution optical satellite data. Most of them show an overall increase of decadal surface velocities from the 1950s onwards with speeds being roughly two to three times higher in recent years compared to the 1950s and 1960s. This development indicates a possible significant increase in sediment and ice fluxes through rock glaciers and implies that – when compared to glacier shrinkage – periglacial sediment transport in the region seems to gain importance relative to glacial sediment transport. Those rock glacier fronts reaching the valley floors show a strongly compressive flow regime, and changes in speeds further upstream affect them only in a damped way. The only rock glacier investigated in detail that does not exhibit an overall increase in speed since the 1950s is Gorodetsky where glacier retreat and dead-ice degradation seem to have decoupled the rock glacier from its supply by glacial sediments and ice.

scholarly journals Inventory and changes of rock glacier creep speeds in Ile Alatau and Kungöy Ala-Too, northern Tien Shan, since the 1950s

2021 ◽  
Vol 15 (2) ◽  
pp. 927-949
Author(s):  
Andreas Kääb ◽  
Tazio Strozzi ◽  
Tobias Bolch ◽  
Rafael Caduff ◽  
Håkon Trefall ◽  
...  
Keyword(s):  
High Resolution ◽  
Tien Shan ◽  
Spatial And Temporal Variability ◽  
European Alps ◽  
Material Transport ◽  
Rock Glacier ◽  
Study Region ◽  
Rock Glaciers ◽  
The 1950S ◽  
Northern Tien Shan

Abstract. Spatio-temporal patterns related to the viscous creep in perennially frozen sediments of rock glaciers in cold mountains have rarely been studied outside the densely populated European Alps. This study investigates the spatial and temporal variability of rock glacier movement in the Ile Alatau and Kungöy Ala-Too mountain ranges, northern Tien Shan, a region with particularly large and fast rock glaciers. Over the study region of more than 3000 km2, an inventory of slope movements was constructed using a large number of radar interferograms and high-resolution optical imagery. The inventory includes more than 900 landforms, of which around 550 were interpreted as rock glaciers. Out of the active rock glaciers inventoried, 45 are characterized by a rate of motion exceeding 100 cm/a. From these fast rock glaciers we selected six (Gorodetzky, Morenny, Archaly, Ordzhonikidze, Karakoram, and Kugalan Tash) and studied them in more detail using offset tracking between repeat aerial images and historical and modern high-resolution optical satellite data. Two of these rock glaciers showed a steady increase in decadal surface velocities from the 1950s onwards, with speeds being roughly 2 to 4 times higher in recent years compared to the 1950s and 1960s. Three rock glaciers showed similar accelerations over the last 1 to 2 decades but also phases of increased speeds in the 1960s. This development indicates a possible significant increase in current sediment and ice fluxes through rock glaciers and implies that their material transport in the region might gain geomorphodynamic importance relative to material transport by glaciers, assuming the latter decreases together with the regional glacier shrinkage. The study demonstrates how air and satellite image archives are exploited to construct one of the longest decennial times series of rock glacier speeds currently available. Our results are in line with findings from Europe about rock glacier speeds increasing with atmospheric warming and underline local variability of such an overall response.

Towards accurate quantification of ground ice content in permafrost of the Central Andes: geophysics-based estimates from three different regions

2021 ◽  
Author(s):  
Christin Hilbich ◽  
Tamara Mathys ◽  
Christian Hauck ◽  
Lukas Arenson
Keyword(s):  
Remote Sensing ◽  
Central Andes ◽  
The Other ◽  
Data Sets ◽  
Rock Glacier ◽  
Ground Ice ◽  
Other Hand ◽  
Rock Glaciers ◽  
Ice Content ◽  
Permafrost Regions

<p>Continued climate change is projected to cause significant temperature increase, yielding substantial water shortage especially in the semi-arid mountain regions of the Central Andes. The role of permafrost occurrences for the hydrological cycle in the Central Andes is currently discussed in a controversial way. On the one hand, permafrost in general, and especially rock glaciers are considered key stores of frozen water in view of the recession of glaciers, and degrading permafrost is expected to partly compensate the decreasing glacial discharge in future. On the other hand, the methodology to quantify ground ice resources in Andean permafrost regions as well as the time scales involved for significant discharge from permafrost bodies are currently disputed.</p><p>Comprehensive and quantitative field-based data on the local variability of internal structure, ground ice content and the hydrological contribution of different permafrost landforms are mostly lacking, and the current debate mostly focuses on rock glaciers as the prominent ice-rich permafrost landforms, as they can easily be identified by remote sensing.</p><p>To ameliorate this lack of ground truth data, we present a quantitative analysis of > 50 Electrical Resistivity Tomography and > 20 Refraction Seismic Tomography profiles from several permafrost sites in different geomorphologic settings, including ice-rich and ice-poor permafrost occurrences. The surveys were conducted between 2016 and 2019 in three different regions of the Central Andes of Chile and Argentina (28 - 32° S) in the framework of several Baseline studies in mining environments. For some sites borehole and test pit data are available and used to validate the quantitative estimates of ground ice contents by the 4-phase model (Hauck et al. 2011).</p><p>We demonstrate the value of geophysical surveys to detect ice-rich permafrost in various landforms (also beyond rock glaciers), and to estimate ground ice volumes in permafrost regions. Our data show, that remote-sensing based approaches tend to significantly overestimate ice volumes of rock glaciers, and on the other hand, that ice-rich permafrost is not restricted to rock glaciers, but also observed in non-rock-glacier permafrost slopes in the form of interstitial ice and layers with excess ice. In regions with widespread occurrence of such permafrost slopes, even relatively thin ice-rich layers can sum up to substantial total ground ice contents, which can be close to the volumes observed in rock glaciers. Consequently, non-rock-glacier permafrost terrain, whose role for local hydrology is basically neglected in remote-sensing based approaches, may be of equal hydrological significance regarding stored ground ice volumes on the catchment scale in some cases, and shall not be ignored.</p><p>The presented data may therefore serve as one of the first available field-based and validated data sets regarding the presence and total quantities of ground ice, and as input for modelling studies about the relative contributions of rock glacier and non-rock glacier permafrost to runoff in the Central Andes.</p><p> </p><p>References</p><p>Hauck C, Böttcher M and Maurer H 2011. A new model for estimating subsurface ice content based on combined electrical and seismic data sets. The Cryosphere 5(2): 453-468.</p>

scholarly journals Assessment and distribution of water quality of Pandoh river basin (PRB), Himachal Pradesh, North India

2021 ◽  
Vol 11 (8) ◽  
Author(s):  
C. Prakasam ◽  
R. Saravanan ◽  
M. K. Sharma ◽  
Varinder S. Kanwar
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
River Basin ◽  
Geographical Information ◽  
North India ◽  
Total Hardness ◽  
Drainage Pattern ◽  
Study Region ◽  
Northern India

AbstractAs the surface water in northern India is the main water resource for regional economic and also supply for drinking and irrigation purposes. However, deficiency of water quality leads to serious water pollution in the Pandoh river basin (PRB). Therefore, the main objective of the present study is to evaluate the quality of surface water. With this objective, surface water samples were collected from the PRB of northern India, and analyzed for pH, EC, turbidity, alkalinity, total dissolved solids, and total hardness. Moreover, geographical information system (GIS) tools were used to prepare the geology, drainage pattern, and location maps of the study region. Surface water quality observed from the PRB has an alkaline nature with a moderately hard type. Further studies are encouraged to better understand the water quality in northern India.

Assessing the Benefits and Economic Feasibility of Stand Improvement for Central Hardwood Forests

2021 ◽  
Author(s):  
Yangyang Wang ◽  
Wu Ma ◽  
Lenny D Farlee ◽  
Elizabeth A Jackson ◽  
Guofan Shao ◽  
...  
Keyword(s):  
River Basin ◽  
Environmental Quality ◽  
Net Present Value ◽  
Economic Feasibility ◽  
Management Tool ◽  
Study Region ◽  
White River ◽  
Incentive Programs ◽  
Incentive Program ◽  
Quality Incentive

Abstract Stand improvement (SI) has been widely accepted as an effective forest management tool. Yet most studies on its economic feasibility for nonindustrial private forest (NIPF) landowners are outdated and focus on the single stand level. The objective of this study was to conduct an economic assessment of SI’s effects and feasibility in hardwood stands for a case study in the White River Basin in Indiana. It is shown that SI could make these forests more productive and sustainable than the prevalent “hands-off” practice by enhancing the timber value of the residual stand (TV), generating regular timber income, and to some degree, reversing the decline in oak dominance. On average, a 25% increment in the TV could be achieved. Although costly for some NIPFs, once combined with voluntary financial incentive programs, SI could meet landowners’ demands for low-cost, high-return investment options. In particular, participation in the Environmental Quality Incentive Program could, on average, increase the net present value of timber income from thinning activities by nearly $1,600 per hectare over the course of 30 years. The spatial analysis revealed that there existed considerable spatial heterogeneity in SI benefits and impacts, suggesting that public incentive programs should be spatially targeted to achieve greater efficiency. Study Implications This study found that stand improvement (SI) could significantly improve the timber value of forestland in the central hardwood region. Participation in voluntary conservation programs, such as the Environmental Quality Incentive Program, could alleviate part of the SI cost thus making it an attractive investment opportunity for private landowners. For the study region, the White River Basin in Indiana, the results suggested that there existed substantial variations in SI’s effectiveness across space. This implied that program administrators of voluntary incentives could improve the efficiency of public funds allocation by considering this spatial variation when evaluating landowners’ applications for incentives.

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