Internal structure and behaviour of a rock glacier in the Arid Andes of Argentina

2002 ◽  
Vol 13 (4) ◽  
pp. 289-299 ◽  
Author(s):  
Flavia A. Croce ◽  
Juan P. Milana
Keyword(s):  
Internal Structure ◽  
Rock Glacier

The structure of a talus-derived rock glacier deduced from its hydrology

1981 ◽  
Vol 18 (9) ◽  
pp. 1422-1430 ◽  
Author(s):  
P. G. Johnson
Keyword(s):  
Internal Structure ◽  
Drainage System ◽  
Yukon Territory ◽  
Flow Structures ◽  
Chemical Characteristics ◽  
Rock Glacier ◽  
Chemical Changes ◽  
Near Surface ◽  
Hydrological Parameters ◽  
Physical Evidence

The paper presents the results of an experiment in the use of hydrological parameters to study the internal structure of a rock glacier. The rock glacier selected for the study lies at the head of Grizzly Creek in the southwest Yukon Territory. The hydrological network suggests two independent drainage systems, which demonstrate the occurrence of a planar impervious structure at depth and independent lines of drainage controlled by the flow structures in the near-surface deposits. Chemical changes in the water are inconclusive with respect to the evaluation of ice contents of the landform although the physical evidence strongly suggests no massive ice component. Chemical characteristics of each drainage system are sufficiently different that chemical tests can be used to differentiate sources of the drainage.

Internal structure of a large, complex rock glacier and its significance in hydrological and dynamic behavior: A case study in the semi‐arid Andes of Argentina

2021 ◽  
Author(s):  
Cristian Daniel Villarroel ◽  
Diana Agostina Ortiz ◽  
Ana Paula Forte ◽  
Guillermo Tamburini Beliveau ◽  
David Ponce ◽  
...  
Keyword(s):  
Internal Structure ◽  
Dynamic Behavior ◽  
Rock Glacier ◽  
Large Complex ◽  
Semi Arid

Internal structure of the Green Lake 5 rock glacier, Colorado Front Range, USA

2011 ◽  
Vol 22 (2) ◽  
pp. 107-119 ◽  
Author(s):  
M. Leopold ◽  
M.W. Williams ◽  
N. Caine ◽  
J. Völkel ◽  
D. Dethier
Keyword(s):  
Internal Structure ◽  
Colorado Front Range ◽  
Front Range ◽  
Rock Glacier ◽  
Green Lake

scholarly journals Internal structure of two alpine rock glaciers investigated by quasi-3-D electrical resistivity imaging

2017 ◽  
Vol 11 (2) ◽  
pp. 841-855 ◽  
Author(s):  
Adrian Emmert ◽  
Christof Kneisel
Keyword(s):  
Electrical Resistivity ◽  
Internal Structure ◽  
Swiss Alps ◽  
Electrical Resistivity Imaging ◽  
Rock Glacier ◽  
Ground Ice ◽  
Resistivity Imaging ◽  
Wide Range ◽  
Rock Glaciers ◽  
Ice Content

Abstract. Interactions between different formative processes are reflected in the internal structure of rock glaciers. Therefore, the detection of subsurface conditions can help to enhance our understanding of landform development. For an assessment of subsurface conditions, we present an analysis of the spatial variability of active layer thickness, ground ice content and frost table topography for two different rock glaciers in the Eastern Swiss Alps by means of quasi-3-D electrical resistivity imaging (ERI). This approach enables an extensive mapping of subsurface structures and a spatial overlay between site-specific surface and subsurface characteristics. At Nair rock glacier, we discovered a gradual descent of the frost table in a downslope direction and a constant decrease of ice content which follows the observed surface topography. This is attributed to ice formation by refreezing meltwater from an embedded snow bank or from a subsurface ice patch which reshapes the permafrost layer. The heterogeneous ground ice distribution at Uertsch rock glacier indicates that multiple processes on different time domains were involved in the development. Resistivity values which represent frozen conditions vary within a wide range and indicate a successive formation which includes several advances, past glacial overrides and creep processes on the rock glacier surface. In combination with the observed topography, quasi-3-D ERI enables us to delimit areas of extensive and compressive flow in close proximity. Excellent data quality was provided by a good coupling of electrodes to the ground in the pebbly material of the investigated rock glaciers. Results show the value of the quasi-3-D ERI approach but advise the application of complementary geophysical methods for interpreting the results.

scholarly journals Internal structure of rock glaciers in Altai (The case of talus rock glacier in Dzhelo River Valley)

2019 ◽  
Vol 9 (4) ◽  
pp. 729-731
Author(s):  
G. S. Dyakova ◽  
A. A. Goreyavcheva ◽  
V. V. Potapov ◽  
A. N. Shein ◽  
D. S. Lobachev ◽  
...  
Keyword(s):  
Internal Structure ◽  
Ice Core ◽  
Digital Terrain Model ◽  
River Valley ◽  
Rock Glacier ◽  
Resistivity Tomography ◽  
Terrain Model ◽  
Ice Volume ◽  
Digital Terrain ◽  
Rock Glaciers

In 2019, a comprehensive study of the internal structure of the talus rock glacier in the Dzhelo River valley was carried out (North-Chuya Range). The identification of the internal structure was performed using electrical resistivity tomography and GPR sounding. In order to compare the internal structure of the rock glacier with its surface morphology, we carried out aerial photography and constructed a digital terrain model. The study revealed that the depth of the rock-ice core varies from 2.5-3 m to 10 m, and the thickness ranges from 7 m to 30 m. The consolidation cores of the rock-ice material are confined to inter-ridge depressions in the rock glacier body. The potential volume of a rock-ice core is 800 thousand m3, which is 53% of the rock glacier total volume, the ice volume in the rock-ice core can be as much as 400 thousand m3.

scholarly journals Dynamics and GPR stratigraphy of a polar rock glacier on James Ross Island, Antarctic Peninsula

2008 ◽  
Vol 54 (186) ◽  
pp. 445-451 ◽  
Author(s):  
Kotaro Fukui ◽  
Toshio Sone ◽  
Jorge A. Strelin ◽  
Cesar A. Torielli ◽  
Junko Mori ◽  
...  
Keyword(s):  
Internal Structure ◽  
Antarctic Peninsula ◽  
Ice Core ◽  
Field Measurements ◽  
Geodetic Survey ◽  
Rock Glacier ◽  
Glacier Surface ◽  
Valley Glacier ◽  
Movement Mechanism ◽  
James Ross Island

AbstractWe describe field measurements (ground-penetrating radar (GPR), geodetic survey and ice-core drilling) to provide new information on the movement mechanism and internal structure of a polar rock glacier on James Ross Island, Antarctic Peninsula. We collected GPR data along longitudinal and transverse profiles. The longitudinal GPR profiles identify inter-bedded debris-rich layers that dip up-glacier, similar to the thrust structures in the compression zone of a valley glacier. The transverse GPR profiles indicate a syncline structure inclined towards the central part of the rock glacier, resembling the transverse foliation of a valley glacier. The stratigraphy of two boreholes shows that the rock glacier consists primarily of bubbly ice with thin debris-rich layers, an internal structure similar to the ‘nested spoons’ structure common in the interior of valley glaciers. These results indicate that the glacier motion is controlled by shear movement, common in valley glaciers. The geodetic survey confirms that flow velocities decrease towards the lower part of the rock glacier. Such heterogeneous movement causes longitudinal compression and forms thrusts which then create the debris-rich layer by uplifting basal ice and debris. Pushing of the upstream ice against the downstream ice bends the surface layers, forming transverse ridges on the rock glacier surface.

Pushing the limits of electrical resistivity tomography measurements on a rock glacier at 5500 m a.s.l. on the Tibetan Plateau: Successes and Challenges

2020 ◽  
Author(s):  
Nora Krebs ◽  
Anne Voigtländer ◽  
Matthias Bücker ◽  
Andreas Hördt ◽  
Ruben Schroeckh ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Tibetan Plateau ◽  
Internal Structure ◽  
Electrical Resistivity Tomography ◽  
High Resistivity ◽  
Mountain Range ◽  
The Tibetan Plateau ◽  
Rock Glacier ◽  
Resistivity Tomography ◽  
Rock Glaciers

<p>Geophysical methods provide a powerful tool to understand the internal structure of active rock glaciers. We applied Electrical Resistivity Tomography (ERT) to a rock glacier at an elevation of 5500 m a.s.l. in the semi-arid Nyainqêntanglha mountain range on the Tibetan plateau, China.  The investigations comprised three transects across the rock glacier and its catchment, each spanning over a distance of 296 m up to 396 m, equipped with 75 up to 100 electrodes respectively. Our measurements were successful in revealing internal structures of the rock glacier, but were also accompanied by challenges.</p><p>We successfully detected first-order permafrost structures, such as a shallow about 4 m thick active layer of low electrical resistivity values that was underlain by potentially ice rich zones of high resistivity. Further high-resistivity zones were found and interpreted as dense bed rock of adjacent slopes that undergird the loose rock glacier debris.</p><p>Challenges, we faced in the application of ERT, were mainly posed by the morphology and internal structure of the rock glacier itself. Coarse debris created a rough surface that prevented a uniform setup with accurate 4 m spacing. The presence of loosely nested blocks of pebble size up to boulders with large interspaces resulted in high contact resistances. The consequent low injection current densities and possible noisy voltage readings downgraded part of the data, causing low data density and resolution. Coupling was partly improved by attaching salt-watered sponges to the electrodes and adding more conductive fine-grained materials to the electrodes. The detected high resistivity ice layer impeded deep penetration of electrical currents, which caused that the lower limit of the permanently frozen zone could not be defined.</p><p>Despite these challenges, the captured ERT profiles are an indispensable contribution to the sparse field data on the internal structure of rock glaciers on the Tibetan plateau. Our results contribute to a better understanding of the prospective evolution of rock glaciers in dry, high mountain ranges under a changing climate.</p>

scholarly journals New insights into ice accumulation at Galena Creek Rock Glacier from radar imaging of its internal structure

2019 ◽  
Vol 66 (255) ◽  
pp. 1-10
Author(s):  
Eric Ivan Petersen ◽  
Joseph S. Levy ◽  
John W. Holt ◽  
Cassie M. Stuurman
Keyword(s):  
Internal Structure ◽  
Debris Avalanche ◽  
Early Spring ◽  
Snow Accumulation ◽  
Rock Glacier ◽  
Debris Accumulation ◽  
Ice Accumulation ◽  
Rock Glaciers ◽  
The Subject ◽  
Ground Penetrating

AbstractThe ice-cored Galena Creek Rock Glacier, Wyoming, USA, has been the subject of a number of studies that sought to determine the origin of its ice. We present new observations of the rock glacier's internal structure from ground-penetrating radar to constrain ice and debris distribution and accumulation. We imaged dipping reflectors in the center of the glacier that are weak and discontinuous, in contrast to strong reflectors toward the edge of the cirque beneath large debris-avalanche chutes. These reflectors form a network of concave-up, up-glacier dipping layers. We interpret these as englacial debris bands formed by large debris falls buried by subsequent ice and snow accumulation. They are discontinuous where ice outpaces debris accumulation, but with sufficient debris accumulation an interleaved pattern of ice and debris layers can form. We propose a model in which the ice in these interleaved layers is snowfall preserved by debris-facilitated accumulation. Large debris falls that occur in early spring bury sections of the snowpack, which are then preserved through summer and incorporated into the rock glacier body over time. This study highlights the importance of sequential accumulation of ice and debris for understanding the dynamics of rock glaciers and debris-covered glaciers.

Internal structure of an alpine rock glacier based on crosshole georadar traveltimes and amplitudes

2006 ◽  
Vol 54 (3) ◽  
pp. 273-285 ◽  
Author(s):  
Martin Musil ◽  
Hansruedi Maurer ◽  
Klaus Hollinger ◽  
Alan G. Green
Keyword(s):  
Internal Structure ◽  
Rock Glacier
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