ALOS-derived glacier and rock glacier inventory of the Volcán Domuyo region (~36° S), southernmost Central Andes, Argentina

Rock glaciers are perennially frozen bodies of ice and rock debris that move downslope primarily due to deformation of internal ice. These features play an important role in alpine hydrology and landscape evolution, and constitute a significant water resource in arid regions. In the Uinta Mountains, Utah, nearly 400 rock glaciers have been identified on the basis of morphology, but the presence of ice has been investigated in only two. Here, I use satellite-based interferometric synthetic-aperture radar (InSAR) from the Copernicus Sentinel-1 satellites to identify and monitor active rock glaciers over a 10,000 km2 area. I also compare the time-dependent motion of several individual rock glaciers over the summers of 2016-2019 to search for relationships with climatic drivers such as precipitation and temperature. Sentinel-1 data from the August-October of 2016-2019 are used to create 79 interferograms of the entire Uinta range and are processed with the NASA/JPL/Stanford InSAR Scientific Computing Environment (ISCE) software package. Temporal baselines of intrayear interferograms range from 6-72 days. We use average velocity maps to generate an active rock glacier inventory for the Uinta Mountains containing 196 active rock glaciers. Average rock glacier velocity is 3 cm/yr in the line-of-sight direction, but individual rock glaciers have velocities ranging from 0.3-15 cm/yr. Rock glacier speeds do have a seasonal component, and were fastest in August across all years. One rock glacier reached a speed of 40 cm/yr over a 12 day interval from August 5 to August 17 of 2017. Preliminary results suggest that active rock glaciers are found at altitudes 10 m higher on average than inactive and relic rock glaciers identified in the previous inventory. Rock glacier movement did not accelerate between 2016 and 2019, suggesting that rock glaciers in this part of the Rocky Mountains are not speeding up over time. Our results highlight the ability to use satellite InSAR to monitor rock glaciers over large areas and provide insight into the factors that control their kinematics.

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Upscaling of geophysical measurements: A methodology for the estimation of the total ground ice content at two study sites in the dry Andes of Chile and Argentina

10.5194/egusphere-egu2020-18397 ◽

2020 ◽

Author(s):

Tamara Mathys ◽

Christin Hilbich ◽

Cassandra E.M. Koenig ◽

Lukas Arenson ◽

Christian Hauck

Keyword(s):

Hydrological Cycle ◽

Spatial Scales ◽

Geophysical Methods ◽

Central Andes ◽

Permafrost Degradation ◽

Rock Glacier ◽

Ground Ice ◽

Refraction Seismic ◽

Geophysical Surveys ◽

Ice Content

With climate change and the associated continuing recession of glaciers, water security, especially in regions depending on the water supply from glaciers, is threatened. In this context, the understanding of permafrost distribution and its degradation is of increasing importance as it is currently debated whether ground ice can be considered as a significant water reservoir and as an alternative resource of fresh water that could potentially moderate water scarcity during dry seasons in the future. Thus, there is a pressing need to better understand how much water is stored as ground ice in areas with extensive permafrost occurrence and how meltwater from permafrost degradation may contribute to the hydrological cycle in the region.Although permafrost and permafrost landforms in the Central Andes are considered to be abundant and well developed, the data is scarce and understanding of the Andean cryosphere lacking, especially in areas devoid of glaciers and rock glaciers.In the absence of boreholes and test pits, geophysical investigations are a feasible and cost-effective technique to detect ground ice occurrences within a variety of landforms and substrates. In addition to the geophysical surveys themselves, upscaling techniques are needed to estimate ground ice content, and thereby future water resources, on larger spatial scales. To contribute to reducing the data scarcity regarding ground ice content in the Central Andes, this study focuses on the permafrost distribution and the ground ice content (and its water equivalent) of two catchments in the semi-arid Andes of Chile and Argentina. Geophysical methods (Electrical Resistivity Tomography, ERT and Refraction Seismic Tomography, RST) were used to detect and quantify ground ice in the study regions in the framework of environmental impact assessments in mining areas. Where available, ERT and RST measurements were quantitatively combined to estimate the volumetric ground ice content using the Four Phase Model (Hauck et al., 2011). Furthermore, we developed one of the first methodologies for the upscaling of these geophysical-based ground ice quantifications to an entire catchment in order to estimate the total ground ice volume in the study areas.In this contribution we will present the geophysical data, the upscaling methodology used to estimate total ground ice content (and water equivalent) of permafrost areas, and some first estimates of total ground ice content in rock glacier and rock glacier free areas and compare them to conventional estimates using remotely sensed data.&#160;Hauck, C., B&#246;ttcher, M., and Maurer, H. (2011). A new model for estimating subsurface ice content based on combined electrical and seismic datasets, The Cryosphere, 5: 453-468.

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

Earth Surface Dynamics ◽

10.5194/esurf-5-493-2017 ◽

2017 ◽

Vol 5 (3) ◽

pp. 493-509 ◽

Cited By ~ 14

Author(s):

Sébastien Monnier ◽

Christophe Kinnard

Keyword(s):

Feature Tracking ◽

Central Andes ◽

Image Feature ◽

Rock Glacier ◽

Aerial Photos ◽

Surface Displacements ◽

Digital Elevation ◽

Elevation Changes ◽

Elevation Model ◽

Displacement Patterns

Abstract. Three glacier–rock glacier transitional landforms in the central Andes of Chile are investigated over the last decades in order to highlight and question the significance of their landscape and flow dynamics. Historical (1955–2000) aerial photos and contemporary (> 2000) Geoeye satellite images were used together with common processing operations, including imagery orthorectification, digital elevation model generation, and image feature tracking. At each site, the rock glacier morphology area, thermokarst area, elevation changes, and horizontal surface displacements were mapped. The evolution of the landforms over the study period is remarkable, with rapid landscape changes, particularly an expansion of rock glacier morphology areas. Elevation changes were heterogeneous, especially in debris-covered glacier areas with large heaving or lowering up to more than ±1 m yr−1. The use of image feature tracking highlighted spatially coherent flow vector patterns over rock glacier areas and, at two of the three sites, their expansion over the studied period; debris-covered glacier areas are characterized by a lack of movement detection and/or chaotic displacement patterns reflecting thermokarst degradation; mean landform displacement speeds ranged between 0.50 and 1.10 m yr−1 and exhibited a decreasing trend over the studied period. One important highlight of this study is that, especially in persisting cold conditions, rock glaciers can develop upward at the expense of debris-covered glaciers. Two of the studied landforms initially (prior to the study period) developed from an alternation between glacial advances and rock glacier development phases. The other landform is a small debris-covered glacier having evolved into a rock glacier over the last half-century. Based on these results it is proposed that morphological and dynamical interactions between glaciers and permafrost and their resulting hybrid landscapes may enhance the resilience of the mountain cryosphere against climate change.

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

10.5194/tc-2016-232-rc1 ◽

2017 ◽

Author(s):

Anonymous

Keyword(s):

Central Andes ◽

Rock Glacier ◽

Mountain Ranges ◽

Northern Sector

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sort of an intact rock glacier inventory

10.5194/essd-2020-158-rc2 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Intact Rock ◽

Rock Glacier ◽

Glacier Inventory

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Quantifying Overestimated Permafrost Extent Driven by Rock Glacier Inventory

Geophysical Research Letters ◽

10.1029/2021gl092476 ◽

2021 ◽

Vol 48 (8) ◽

Author(s):

Bin Cao ◽

Xin Li ◽

Min Feng ◽

Donghai Zheng

Keyword(s):

Rock Glacier ◽

Glacier Inventory

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

10.5194/esurf-2016-16 ◽

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.

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Permafrost Favorability Index: Spatial Modeling in the French Alps Using a Rock Glacier Inventory

Frontiers in Earth Science ◽

10.3389/feart.2017.00105 ◽

2017 ◽

Vol 5 ◽

Cited By ~ 16

Author(s):

Marco Marcer ◽

Xavier Bodin ◽

Alexander Brenning ◽

Philippe Schoeneich ◽

Raphaële Charvet ◽

...

Keyword(s):

Spatial Modeling ◽

Rock Glacier ◽

Glacier Inventory ◽

French Alps

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Ice Mass Loss in the Central Andes of Argentina Between 2000 and 2018 Derived From a New Glacier Inventory and Satellite Stereo-Imagery

Frontiers in Earth Science ◽

10.3389/feart.2020.530997 ◽

2020 ◽

Vol 8 ◽

Author(s):

Lidia Ferri ◽

Inés Dussaillant ◽

Laura Zalazar ◽

Mariano H. Masiokas ◽

Lucas Ruiz ◽

...

Keyword(s):

Mass Balance ◽

River Discharge ◽

Central Andes ◽

Glacier Inventory ◽

Ice Surface ◽

Stereo Imagery ◽

Rock Glaciers ◽

Crucial Information ◽

Debris Coverage ◽

Limited Sensitivity

Based on the recently released National Glacier Inventory (NGI), we analyzed the characteristics and the mass balance rates of ice masses in the Argentinean Central Andes (ca. 30°–37° S). The NGI provides unprecedented information on area, number and distribution of different ice masses, including debris-covered glaciers and rock glaciers. In the Central Andes, a number of 8,076 ice masses were identified covering a total area of 1767 km2. For the period 2000–2018, a general lowering of the ice surface was observed with a region-wide mass balance rate of −0.18 ± 0.19 m w.e. yr−1. Clear differences depending on the debris coverage of the different ice masses were identified, with mass balance rates ranging from −0.36 ± 0.19 m w.e. yr−1 for partly debris-covered glaciers to −0.02 ± 0.19 m w.e. yr−1 for rock glaciers. Considering different sub-periods, the region-wide mass balance rate was slightly positive (+0.12 ± 0.23 m w. e. yr−1) from 2000 to 2009 and negative (−0.21 ± 0.30 m w.e. yr−1) from 2009 to 2018. A comparison with the Randolph Glacier Inventory (RGI version 6.0) indicates that the NGI provides more detailed information regarding different type of ice masses whereas region-wide mass balance rates show limited sensitivity to the choice of the inventory. The inclusion of rock glaciers and “debris-covered ice with rock glacier” in the NGI causes mass balance rates to be slightly less negative than when using the RGI. Since the Central Andes are experiencing an unprecedented decade-long drought, our study provides crucial information to estimate current and future hydrological contribution of the different type of ice masses to river discharge in the arid subtropical Andes.

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