scholarly journals Monitoring of ice avalanche using aerospace and ground information

2020 ◽  
Vol 913 ◽  
pp. 052040
Author(s):  
M D Dokukin ◽  
M Yu Bekkiev ◽  
Kh M Kalov ◽  
R H Kalov
Keyword(s):  
Ice Avalanche

The Ice Avalanche of the Gemmi Pass (Switzerland)

1895 ◽  
Vol 40 (1035supp) ◽  
pp. 16550-16550
Author(s):  
C. S. Du Riche Preller
Keyword(s):  
Ice Avalanche

Resolving pre-collapse slope motion at the February 2021 Chamoli rock-ice avalanche via feature tracking of optical satellite imagery

2021 ◽  
Author(s):  
Maximillian Van Wyk de Vries ◽  
Shashank Bhushan ◽  
David Shean ◽  
Etienne Berthier ◽  
César Deschamps-Berger ◽  
...  
Keyword(s):  
High Resolution ◽  
Satellite Imagery ◽  
Feature Tracking ◽  
Satellite Image ◽  
Image Feature ◽  
Sampling Distance ◽  
Velocity Changes ◽  
The Stability ◽  
Slide Area ◽  
Ice Avalanche

<p>On the 7<sup>th</sup> of February 2021, a large rock-ice avalanche triggered a debris flow in Chamoli district, Uttarakhand, India, resulting in over 200 dead or missing and widespread infrastructure damage. The rock-ice avalanche originated from a steep, glacierized north-facing slope with a history of instability, most recently a 2016 ice avalanche. In this work, we assess whether the slope exhibited any precursory displacement prior to collapse. We evaluate monthly slope motion over the 2015 and 2021 period through feature tracking of high-resolution optical satellite imagery from Sentinel-2 (10 m Ground Sampling Distance) and PlanetScope (3-4 m Ground Sampling Distance). Assessing slope displacement of the underlying rock is complicated by the presence of glaciers over a portion of the collapse area, which display surface displacements due to internal ice deformation. We overcome this through tracking the motion over ice-free portions of the slide area, and evaluating the spatial pattern of velocity changes in glaciated areas. Preliminary results show that the rock-ice avalanche bloc slipped over 10 m in the 5 years prior to collapse, with particularly rapid slip occurring in the summer of 2017 and 2018. These results provide insight into the precursory conditions of the deadly rock-ice avalanche, and highlight the potential of high-resolution optical satellite image feature tracking for monitoring the stability of high-risk slopes.</p>

scholarly journals Movement Studies on a Hanging Glacier in Relation with an Ice Avalanche

1977 ◽  
Vol 19 (81) ◽  
pp. 671-672 ◽  
Author(s):  
André Flotron
Keyword(s):  
Flow Pattern ◽  
The State ◽  
Least Square ◽  
Velocity Versus ◽  
Surface Part ◽  
Different Types ◽  
Best Fit ◽  
Ice Avalanche

AbstractIn 1972 the state of a hanging glacier on the Weisshorn gave cause for alarm, as part of it seemed to be accelerating and a repetition of an earlier avalanche of ice seemed possible (see Röthlisberger, previous abstract). For this reason movement surveys were undertaken. The various surveying methods applied on the Weisshorn are outlined and the accuracy of the measurements is given. By least-square analysis different types of curves have been fitted to the data for velocity versus time. The best fit obtained so-far has been with hyperbolae. The confidence of extrapolations from such curves is discussed in relation to forecasts. By evaluating repeated photographs taken by an automatic camera from a single position, using a stereo plotter, the flow pattern has been established at the surface, part of the front, and one of the lateral faces of the ice mass. Changes with time caused by the deformation of the ice mass, the formation of crevasses and the crumbling away of the ice at the edge have been observed.

scholarly journals Glacier lake outburst floods of the Guangxieco Lake in 1988 in Tibet, China

2013 ◽  
Vol 1 (5) ◽  
pp. 4605-4634 ◽  
Author(s):  
J. J. Liu ◽  
Z. L. Cheng ◽  
Y. Li
Keyword(s):  
Global Warming ◽  
Debris Flow ◽  
Satellite Images ◽  
High Elevation ◽  
Viscous Debris Flow ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Ice Avalanche ◽  
Archive Material

Abstract. Glacial lake outburst floods (GLOFs) have become more frequent and attracted more and more attention under conditions of global warming. However, there are few observations of the reasons for outbursts and their processes because of their unexpected occurrence and their inaccessible location in high-elevation areas. The GLOF of the Guangxieco Lake, which is the only outburst lake below an elevation of 4000 m in Tibet, provides a case study for discussing the reasons for outbursts. This paper reconstructs the process in detail using geomorphological evidence, interviews of the local inhabitants, archive material and satellite images. It was found that: (1) There were three main reasons for the GLOF in 1988: intense pre-precipitation and persistent high temperatures before the outburst, ice avalanche by rapid movement of the Gongzo Glacier and low self-stability of the end-moraine dam by perennial piping. (2) The GLOF with the peak discharge of 1270 m3 s-1 was evolved along the Midui Valley following sediment-laden flow–non-viscous debris flow–viscous debris flow–non-viscous debris flow–sediment-laden flood. Eventually the sediment-laden floods blocked the Palongzangbu River. (3) Comparing the conditions for the outburst in 1988 and at present, the possibility of a future outburst is thought to be small unless the glacier moves rapidly again.

scholarly journals Tracking the impacts of the Aru glacier collapses on downstream lakes

2020 ◽  
Author(s):  
Yanbin Lei ◽  
Tandong Yao ◽  
Lide Tian ◽  
Yongwei Sheng ◽  
Jingjuan Liao ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Lake Level ◽  
In Situ Observation ◽  
Lake Surface ◽  
Level Increase ◽  
Lake Morphology ◽  
Western Tibetan Plateau ◽  
Ice Avalanche

Abstract. Two giant glaciers at the Aru range, western Tibetan Plateau, collapsed suddenly on 17 July and 21 September 2016, respectively, causing fatal damage to local people and their livestock. The ice avalanches, with a total volume of 150 × 106 m3, had almost melted by September 2019. Based on in-situ observation, bathymetry survey and satellite data, here we show the impacts of the two glacier collapses on the downstream lakes, the outflow Aru Co and the terminal Memar Co, in terms of lake morphology, water level and water temperature in the subsequent four years (2016–2019). After the first glacier collapse, the ice avalanche slid into Aru Co along with a large amount of debris, which significantly modified the lake’s shoreline and bathymetry. Lake surface temperature (LST) at Aru Co and Memar Co exhibited a significant decrease of 2–4 oC in the first 1–2 weeks after the first glacier collapse due to the intruding ice into Aru Co and its melting. Memar Co significantly deepened by 12.5 m between 2000 and 2018, with accelerated lake level increase after the glacier collapses. Memar Co expanded rapidly at a rate of 0.80 m/yr between 2016 and 2019, which is about 30 % higher than the average rising rate between 2003 and 2014. The meltwater from ice avalanches was found to contribute to about 26.4 % of the increase in lake storage between 2016 and 2019. This study implies that the Aru glacier collapses had long-term and dramatic impacts on the downstream lakes.

scholarly journals Movement Studies on a Hanging Glacier in Relation with an Ice Avalanche

1977 ◽  
Vol 19 (81) ◽  
pp. 671-672 ◽  
Author(s):  
André Flotron
Keyword(s):  
Flow Pattern ◽  
The State ◽  
Least Square ◽  
Velocity Versus ◽  
Surface Part ◽  
Different Types ◽  
Best Fit ◽  
Ice Avalanche

Abstract In 1972 the state of a hanging glacier on the Weisshorn gave cause for alarm, as part of it seemed to be accelerating and a repetition of an earlier avalanche of ice seemed possible (see Röthlisberger, previous abstract). For this reason movement surveys were undertaken. The various surveying methods applied on the Weisshorn are outlined and the accuracy of the measurements is given. By least-square analysis different types of curves have been fitted to the data for velocity versus time. The best fit obtained so-far has been with hyperbolae. The confidence of extrapolations from such curves is discussed in relation to forecasts. By evaluating repeated photographs taken by an automatic camera from a single position, using a stereo plotter, the flow pattern has been established at the surface, part of the front, and one of the lateral faces of the ice mass. Changes with time caused by the deformation of the ice mass, the formation of crevasses and the crumbling away of the ice at the edge have been observed.

scholarly journals Hazard assessment investigations due to recent changes in Triftgletscher, Bernese Alps, Switzerland

2011 ◽  
Vol 11 (8) ◽  
pp. 2149-2162 ◽  
Author(s):  
P. Dalban Canassy ◽  
A. Bauder ◽  
M. Dost ◽  
R. Fäh ◽  
M. Funk ◽  
...  
Keyword(s):  
Peak Velocity ◽  
The Other ◽  
Balance Model ◽  
Impulse Wave ◽  
Mass Balance Model ◽  
Strong Decrease ◽  
Volume Changes ◽  
Surface Motion ◽  
The Impact ◽  
Ice Avalanche

Abstract. The details and the consequences of the recent retreat of Triftgletscher (Gadmertal, Bernese Alps, Switzerland) have been investigated. Geodetic volume changes indicate a strong decrease since 1929 while the position of the terminus remained practically unchanged until 1990. The role played by calving in the tongue retreat running from 2000 to 2006 is confirmed by means of a mass balance model including a calving criterion. Results show that without calving, it would have taken two years longer for the lake to form than has been observed. The consequences of the ensuing tongue destabilization are surveyed, first with an ice avalanche model and second with a hydraulic study of the potential impulse wave triggered by the impact of the falling ice mass in the lake. Results point out that ice avalanches with volumes greater that 1 × 106 m3 will flow into the lake and that in the worst scenario, a discharge of 400 m3 s−1 is expected to reach the endangered area in Gadmertal 11 min after the break-off. In order to detect surface motion precursors to such ice avalanches, a photographic monitoring system was installed. The results indicate seasonal variations with peak velocity in summer and no significant change during the other months. Spectacular velocity increases were not observed so far.

scholarly journals Ice Avalanches: Some Empirical Information about their Formation and Reach

1985 ◽  
Vol 31 (109) ◽  
pp. 324-333 ◽  
Author(s):  
Jürg Alean
Keyword(s):  
Seasonal Variation ◽  
Snow Avalanches ◽  
Empirical Information ◽  
Abrupt Changes ◽  
Short Run ◽  
The Alps ◽  
Improved Accuracy ◽  
Two Parameter ◽  
Ice Avalanche ◽  
Terrain Characteristics

AbstractA study intended to be mainly of practical use in the prediction of ice-avalanche hazards was carried out. About 100 ice avalanches, mostly from the Alps, were documented. Starting zones of these ice avalanches could be classified by using simple terrain characteristics. Ice avalanches from some starting zones at relatively low altitudes and with large, homogeneously inclined bedrock planes occur predominantly in summer and autumn. No such seasonal variation in frequency was found in connection with other types of starting zones occurring either at higher altitudes or involving abrupt changes of the bedrock’s gradient. One- and two-parameter models for the estimation of run-out distances of landslides and snow avalanches were tested for their use with ice avalanches. Introduction of the second (v2proportional) frictional parameter leads only to moderately improved accuracy in the prediction of run-out distances. For relatively short run-out distances (several hundred meters), an alternative method of estimation, based on terrain characteristics, is proposed.

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