Using InSAR to asses rock glacier movement in the Uinta Mountains, Utah

2020 ◽  
Author(s):  
George Brencher ◽  
Alexander Handwerger ◽  
Jeffrey Munroe
Keyword(s):  
Arid Regions ◽  
Interferometric Synthetic Aperture Radar ◽  
Rock Glacier ◽  
Uinta Mountains ◽  
Glacier Inventory ◽  
Rock Glaciers ◽  
Climatic Drivers ◽  
Glacier Velocity ◽  
Alpine Hydrology ◽  
Insight Into

<p>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 km<sup>2 </sup>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.</p>

scholarly journals InSAR-based characterization of rock glacier movement in the Uinta Mountains, Utah, USA

2020 ◽  
Author(s):  
George Brencher ◽  
Alexander L. Handwerger ◽  
Jeffrey S. Munroe
Keyword(s):  
Snow Water Equivalent ◽  
Late Summer ◽  
Rock Glacier ◽  
Mean Velocity ◽  
Uinta Mountains ◽  
Mountain Environments ◽  
Prominent Component ◽  
Snow Water ◽  
Rock Glaciers ◽  
Climatic Drivers

Abstract. Rock glaciers are a prominent component of many alpine landscapes and constitute a significant water resource in some arid mountain environments. Here, we employ satellite-based interferometric synthetic aperture radar (InSAR) to identify and monitor active rock glaciers in the Uinta Mountains (Utah, USA), an area of ~10,000 km2. We used mean velocity maps to generate an inventory for the Uinta Mountains containing 255 active rock glaciers. Active rock glaciers are 10.8 ha in area on average, and located at a mean elevation of 3290 m, where mean annual air temperature is 0.12 °C. The mean line-of-sight (LOS) velocity for the inventory is 2.52 cm/yr, but individual rock glaciers have LOS velocities ranging from 0.88 to 5.26 cm/yr. To search for relationships with climatic drivers, we investigate the time-dependent motion of three rock glaciers over the summers of 2016–2019. Time series analysis suggests that rock glacier motion has a significant seasonal component, with motion that is more than 5 times faster during the late summer compared to rest of the year. Rock glacier velocities also appear to be correlated with the snow-water equivalent of the previous winter's snowpack. These results demonstrate the ability to use satellite InSAR to monitor rock glaciers over large areas and provide insight into the environmental factors that control their kinematics.

scholarly journals InSAR-based characterization of rock glacier movement in the Uinta Mountains, Utah, USA

2021 ◽  
Vol 15 (10) ◽  
pp. 4823-4844
Author(s):  
George Brencher ◽  
Alexander L. Handwerger ◽  
Jeffrey S. Munroe
Keyword(s):  
Snow Water Equivalent ◽  
Late Summer ◽  
Rock Glacier ◽  
Mean Velocity ◽  
Uinta Mountains ◽  
Mountain Environments ◽  
Prominent Component ◽  
Snow Water ◽  
Rock Glaciers ◽  
Climatic Drivers

Abstract. Rock glaciers are a prominent component of many alpine landscapes and constitute a significant water resource in some arid mountain environments. Here, we employ satellite-based interferometric synthetic aperture radar (InSAR) between 2016 and 2019 to identify and monitor active and transitional rock glaciers in the Uinta Mountains (Utah, USA), an area of ∼3000 km2. We used mean velocity maps to generate an inventory for the Uinta Mountains containing 205 active and transitional rock glaciers. These rock glaciers are 11.9 ha in area on average and located at a mean elevation of 3308 m, where mean annual air temperature is −0.25 ∘C. The mean downslope velocity for the inventory is 1.94 cm yr−1, but individual rock glaciers have velocities ranging from 0.35 to 6.04 cm yr−1. To search for relationships with climatic drivers, we investigated the time-dependent motion of three rock glaciers. We found that rock glacier motion has a significant seasonal component, with rates that are more than 5 times faster during the late summer compared to the rest of the year. Rock glacier velocities also appear to be correlated with the snow water equivalent of the previous winter's snowpack. Our results demonstrate the ability to use satellite InSAR to monitor rock glaciers over large areas and provide insight into the environmental factors that control their kinematics.

scholarly journals Modelling rock glacier velocity and ice content, Khumbu and Lhotse Valleys, Nepal

2021 ◽  
Author(s):  
Yan Hu ◽  
Stephan Harrison ◽  
Lin Liu ◽  
Joanne Laura Wood
Keyword(s):  
Current Knowledge ◽  
Slope Angle ◽  
Water Volume ◽  
Active Layer Thickness ◽  
Rock Glacier ◽  
Average Value ◽  
Mountain Glaciers ◽  
Rock Glaciers ◽  
Glacier Velocity ◽  
Ice Content

Abstract. Rock glaciers contain significant amount of ground ice and serve as important freshwater resources as mountain glaciers melt in response to climate warming. However, current knowledge about ice content in rock glaciers has been acquired mainly from in situ investigations in limited study areas, which hinders a comprehensive understanding of ice storage in rock glaciers situated in remote mountains and over local or regional scales. In this study, we develop an empirical rheological model to infer ice content of rock glaciers using readily available input data, including rock glacier planar shape, surface slope angle, active layer thickness, and surface creep rate. We apply the model to infer the ice content of five rock glaciers in Khumbu and Lhotse Valleys, north-eastern Nepal. The inferred volumetric ice fraction ranges from 57.5 % to 92 %, with an average value between 71 % to 75.3 %. The total water volume equivalent in the study area lies between 10.61 and 16.54 million m3. Considering previous mapping results and extrapolating from our findings to the entire Nepalese Himalaya, the total amount of water stored in rock glaciers ranges from 8.97 to 13.98 billion m3, equivalent to a ratio of 1 : 17 between the rock glacier and glacier reservoirs. Due to the accessibility of the input parameters of the model developed in this study, it is promising to apply the approach to permafrost regions where previous information about ice content of rock glaciers is lacking.

scholarly journals Rock Glacier Kinematics in the Kaunertal, Ötztal Alps, Austria

Geosciences ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 373 ◽  
Author(s):  
Till Groh ◽  
Jan Henrik Blöthe
Keyword(s):  
High Resolution ◽  
Aerial Imagery ◽  
Local Analysis ◽  
Data Sets ◽  
Rock Glacier ◽  
Glacier Inventory ◽  
Logistic Regression Models ◽  
Image Tracking ◽  
Rock Glaciers ◽  
Regional Basis

The quantification of rock glacier kinematics on a regional basis has gained increasing importance in recent years. Here, we applied an image tracking approach on high-resolution aerial imagery to infer surface kinematics of 129 mapped rock glaciers in the Kaunertal, Austrian Alps. We find significant surface movement for 30 features with mean velocities falling between 0.11 and 0.29 m yr−1 and a maximum of 1.7 m yr−1. Local analysis and comparison to earlier studies reveals significant increases in rock glacier velocities in the study area. From the rock glacier inventory and high-resolution digital topography, we computed a series of morphometric parameters to analyze potential controls on rock glacier creep and to predict rock glacier activity using random forests and logistic regression models. The results point towards a stronger dependence of velocities on parameters describing general inclination, potentially acting as proxies for internal rock glacier properties, while activity states seem to be regulated mainly by rock glacier dimensions and topoclimate. Using a parameter subset, we successfully separated active from inactive rock glaciers with accuracies of up to 77.5%, indicating a promising approach to predict rock glacier activity solely relying on parameters that can be derived from regionally available data sets.

Monitoring of rock glacier flow velocity variations using imagery, laser scan data and ground-based interferometric synthetic aperture radar (GBInSAR) at the Finstertal reservoir (Austria)

2020 ◽  
Author(s):  
Christine Fey ◽  
Erik Kuschel ◽  
Anna Sara Amabile ◽  
Wolfgang Straka ◽  
Christian Zangerl
Keyword(s):  
Flow Velocity ◽  
Aerial Imagery ◽  
Interferometric Synthetic Aperture Radar ◽  
Rock Glacier ◽  
Time Period ◽  
Rock Glaciers ◽  
Velocity Variations ◽  
Scan Data ◽  
Glacier Flow ◽  
Flow Velocities

<p>Rock glaciers are geomorphological phenomena of mountain permafrost which slowly move downslope as a consequence of the ice deformation. During the last few decades, many rock glaciers in the Alps are showing an increase of flow velocities which is most probably caused by climate change. However, the factors influencing the flow velocities (e.g. air temperature, meltwater infiltration, internal rock glacier characteristics) are not fully understood. Data about the annual, inter-annual and diurnal rock glacier flow velocities are essential to understand the influence of climatic factors on rock glaciers.</p><p>This study focused on the Finstertal rock glacier, located in the Eastern Alps, where flow velocities are reconstructed since the 1970s based on aerial imagery, airborne and terrestrial laser scan data. Since 2014, a terrestrial laser scanning (TLS) based monitoring is implemented. The maximum flow velocities of the Finstertal rock glacier increased from 0.1 m/year (time period 1970-1997) to 1.4 m/year (time period 2015-2016) and is currently about 1.3 m/ year (time period 2018-2019).</p><p>The accuracy of aerial imagery and laser scan data is in the range of centimetres and well suited to analyse the annual variability of rock glaciers. Imagery and laser scan data are not suited for shorter time intervals, where the absolute displacement of a rock glacier is smaller than the measurement accuracy. Consequently, for the understanding of interannual and diurnal variations in rock glacier flow velocities, other measurement methods are needed. Ground-based interferometric synthetic aperture radar (GBInSAR) is able to detect spatial deformations in the range of sub-centimeters.</p><p>Therefore, to get a more detailed understanding of the rock glacier flow velocity variations, a GBInSAR was installed on Finstertal hydroelectric dam to measure the rock glacier flow velocities between October to November 2019. In this study, preliminary results on diurnal flow velocity variations of Finstertal rock glacier, based on GBInSAR, are presented, and compared to annual variations derived from aerial imagery and laser scan data.</p>

scholarly journals Observations on a Debris-Covered Polar Glacier “Whisky Glacier”, James Ross Island, Antarctic Peninsula, Antarctica

1987 ◽  
Vol 33 (115) ◽  
pp. 300-310 ◽  
Author(s):  
T.J.H. Chinn ◽  
A. Dillon
Keyword(s):  
Antarctic Peninsula ◽  
Rock Glacier ◽  
Freezing Front ◽  
Extensive Area ◽  
Free Zone ◽  
Rock Glaciers ◽  
James Ross Island ◽  
Polythermal Glacier ◽  
Powerful Mechanism

Abstract“Whisky Glacier” on James Ross Island, Antarctic Peninsula, comprises anévéand clean ice trunk surrounded by an extensive area of debris-covered ice resembling a rock glacier. The debris-free trunk of the glacier abuts abruptly against the broad, totally debris-covered tongue at a number of concentric zones where debris-laden beds crop out at the surface in a manner similar to the “inner moraine” formations of many polar glaciers.Ice structures and foliation suggest that “Whisky Glacier” is a polythermal glacier which is wet-based under the debris-free zone, and dry-based under the debris-covered zone. It is surmised that the glacier sole crosses the freezing front close to where the basal debris beds are upwarped towards the surface. Here, basal water is confined, and freezes to the under side of the glacier in thick beds of regelation ice which are uplifted to the surface along with the debris-laden beds. Ablation losses effectively cease beneath the blanket of debris covering the tongue.The transition from wet-based to dry-based conditions at the glacier sole is a powerful mechanism for entraining debris into a glacier and, in the case of “Whisky Glacier”, for lifting debris to the surface. It is suggested that this may be a mechanism for forming some polar rock glaciers.

Schmidt-hammer exposure-age dating (SHD) of rock glaciers in the Schöderkogel-Eisenhut area, Schladminger Tauern Range, Austria

The Holocene ◽  
2011 ◽  
Vol 22 (7) ◽  
pp. 761-771 ◽  
Author(s):  
Matthias Rode ◽  
Andreas Kellerer-Pirklbauer
Keyword(s):  
Root Zone ◽  
Age Dating ◽  
Surface Velocity ◽  
Schmidt Hammer ◽  
Rock Glacier ◽  
Relative Age ◽  
Exposure Age ◽  
Rock Glaciers ◽  
Glacier Length ◽  
Eastern Austria

Schmidt-hammer rebound values ( R-values) enable relative-age dating of landforms, with R-values relating to degree of weathering and therefore length of exposure. This method – recently termed as Schmidt-hammer exposure-age dating (SHD) – was applied to date five rock glaciers (size range, 0.01–0.12 km2) and one recent rockfall deposit at the study area Schöderkogel-Eisenhut, in the Schladminger Tauern Range (14°03′E, 47°15′N), Austria. The rock glaciers consist of gneiss or high metamorphic series of mica-schist that are comparable in their R-values. Four of them are relict (permafrost absent) and one is intact (containing patches of permafrost). On each of the five rock glaciers, SHD was carried out at 4–6 sites (50 measurements per site) along a longitudinal transect from the frontal ridge to the root zone. Results at all five rock glaciers are generally consistent with each other sharing statistically significant R-values along transects. The range between the highest and the lowest mean R-value at each of the five rock glaciers is 9.9–5.2. Using rock glacier length and surface velocity data from nearby sites, the rock glacier development must have lasted for several thousand years. Furthermore, by using SHD results from rock glaciers of known age from other sites in the region with comparable geology, approximate surface ages of 6.7–11.4 ka were estimated. This indicates long formation periods for all five rock glaciers. Our results suggest that many of the 1300 relict rock glaciers in central and eastern Austria were formed over a long period during the Lateglacial and Holocene period.

scholarly journals Photo-Interpretation of two Types of Rock Glacier in the Colorado Front Range, U.S.A.

1965 ◽  
Vol 5 (42) ◽  
pp. 849-856 ◽  
Author(s):  
Samuel I. Outcalt ◽  
James B. Benedict
Keyword(s):  
Wall Rock ◽  
Colorado Front Range ◽  
Front Range ◽  
Rock Glacier ◽  
Floor Rock ◽  
Glacial Ice ◽  
Photo Interpretation ◽  
Two Generations ◽  
Rock Glaciers ◽  
Small Valley

AbstractTwo types of rock glacier occur in the Colorado Front Range. Rock glaciers on the floors of modern cirques closely resemble the tongues of small valley glaciers. Because they contain cores of banded glacial ice and grade up-valley into lateral moraines, rock glaciers of this type are believed to represent the debris-covered tongues of former glaciers. Most consist of two or more superimposed lobes, bounded by longitudinal furrows, and resulting from independent ice advances. Despite their compound nature, the complexes now appear to be moving down-slope as single units. Two generations of “cirque-floor” rock glaciers, both tentatively dated as being of post-Pleistocene age, occur in the Front Range.Rock glaciers of an entirely different character occur beneath steep valley walls, where they are supplied with debris by avalanche couloirs. Interstitial ice, responsible for the movement of “valley-wall” rock glaciers, probably results from the metamorphism of snow buried beneath rock-fall debris or supplied by winter avalanching.

scholarly journals Short-term velocity variations at three rock glaciers and their relationship with meteorological conditions

2016 ◽  
Vol 4 (1) ◽  
pp. 103-123 ◽  
Author(s):  
V. Wirz ◽  
S. Gruber ◽  
R. S. Purves ◽  
J. Beutel ◽  
I. Gärtner-Roer ◽  
...  
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Ground Surface ◽  
Climatic Conditions ◽  
Water Infiltration ◽  
High Temporal Resolution ◽  
Rock Glacier ◽  
Short Term ◽  
Rock Glaciers ◽  
Velocity Variations

Abstract. In recent years, strong variations in the speed of rock glaciers have been detected, raising questions about their stability under changing climatic conditions. In this study, we present continuous time series of surface velocities over 3 years of six GPS stations located on three rock glaciers in Switzerland. Intra-annual velocity variations are analysed in relation to local meteorological factors, such as precipitation, snow(melt), and air and ground surface temperatures. The main focus of this study lies on the abrupt velocity peaks, which have been detected at two steep and fast-moving rock glacier tongues ( ≥  5 m a−1), and relationships to external meteorological forcing are statistically tested.The continuous measurements with high temporal resolution allowed us to detect short-term velocity peaks, which occur outside cold winter conditions, at these two rock glacier tongues. Our measurements further revealed that all rock glaciers experience clear intra-annual variations in movement in which the timing and the amplitude is reasonably similar in individual years. The seasonal decrease in velocity was typically smooth, starting 1–3 months after the seasonal decrease in temperatures, and was stronger in years with colder temperatures in mid winter. Seasonal acceleration was mostly abrupt and rapid compared to the winter deceleration, always starting during the zero curtain period. We found a statistically significant relationship between the occurrence of short-term velocity peaks and water input from heavy precipitation or snowmelt, while no velocity peak could be attributed solely to high temperatures. The findings of this study further suggest that, in addition to the short-term velocity peaks, the seasonal acceleration is also influenced by water infiltration, causing thermal advection and an increase in pore water pressure. In contrast, the amount of deceleration in winter seems to be mainly controlled by winter temperatures.

scholarly journals Ice content and interannual water storage changes of an active rock glacier in the dry Andes of Argentina

2020 ◽  
Author(s):  
Christian Halla ◽  
Jan Henrik Blöthe ◽  
Carla Tapia Baldis ◽  
Dario Trombotto ◽  
Christin Hilbich ◽  
...  
Keyword(s):  
Seismic Refraction ◽  
Water Storage ◽  
Field Studies ◽  
High Mountain ◽  
Rock Glacier ◽  
Mountain Catchment ◽  
Rock Glaciers ◽  
Ice Content ◽  
Surface Ice ◽  
Water Contents

Abstract. The quantification of volumetric ice and water contents in active rock glaciers is necessary to estimate their role as water stores and contributors to runoff in dry mountain catchments. In the semi-arid to arid Andes of Argentina, active rock glaciers potentially constitute important water reservoirs due to their widespread distribution. Here however, water storage capacities and their interannual changes have so far escaped quantification in detailed field studies. Volumetric ice and water contents were quantified using a petrophysical four-phase model (4PM) based on complementary electrical resistivities (ERT) and seismic refraction tomographies (SRT) in different positions of Dos Lenguas rock glacier in the Upper Agua Negra basin, Argentina. We derived vertical and horizontal surface changes of the Dos Lenguas rock glacier, for the periods 2016–17 and 2017–18 using drone-derived digital elevation models (DEM). Interannual water storage changes of −36 mm yr−1 and +27 mm yr−1 derived from DEMs of Difference (DoD) for the periods 2016–17 and 2017–18, respectively, indicate that significant amounts of annual precipitation rates can be stored in and released from the active rock glacier. Heterogeneous ice and water contents show ice-rich permafrost and supra-, intra- and sub-permafrost aquifers in the subsurface. Active layer and ice-rich permafrost control traps and pathways of shallow ground water, and thus regulate interannual storage changes and water releases from the active rock glacier in the dry mountain catchment. The ice content of 1.7–2.0 × 109 kg in the active Dos Lenguas rock glacier represents an important long-term ice reservoir, just like other ground ice deposits in the vicinity, if compared to surface ice that covers less than 3 % of the high mountain catchment.

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