Ice Avalanche Activity and Mass Balance of a High-Altitude Hanging Glacier in the Swiss Alps
14
Citation
2
Reference
10
Related Paper
Citation Trend
Abstract:
An estimation of average mass balance of a high hanging glacier in the Swiss Alps was made by measuring volumes of ice avalanches originating from this glacier. Ice avalanches are this glacier’s predominant form of ablation. Since the volume of the glacier has not noticeably changed over the past few years, the annual ice loss due to ice avalanches can be taken as an indication of average total net acumulation above the ice cliff where the avalanches originate. The mass balance value, as determined by recording ice avalanches, compares well with values obtained by independent methods (measurements of firn stratigraphy in the cliff, direct accumulation measurements in the vicinity). No seasonal variation in the frequency of ice avalanche occurence was detected.Keywords:
Firn
Glacier ice accumulation
Glacier mass balance
Accumulation zone
Cliff
Glacier morphology
Glacier surface ice velocity is one of the important parameters which determine the glacier dynamics. If the surface ice velocity is high in upper zone (accumulation zone) of the glacier, more ice is brought to the lower zone (ablation zone) of the glacier where it melts more rapidly. The surface ice velocity depends on multiple factors like geomorphology of a glacier and glacier valley, ice load, orientation of the glacier, slope and debris cover. In this study, we have used latest multi-temporal Landsat-8 satellite images to calculate the surface ice velocity of different glaciers from the Himalayan region and a relationship of velocity and geomorphology and geo-morphometry of the glacier has been studied. The standard procedure has been implied to estimate the glacial velocity using image to image correlation technique. The geo-morphometric parameters of the glacier surface have been derived using SRTM 90 m global DEM. It has been observed that the slope of the glacier is one of the main factors on which the velocity is dependent i.e. higher the slope higher is the velocity and more ice is brought by the glacier to the ablation zone. The debris cover over the glacier and at the terminus also affects the velocity of the glacier by restricting ice flow. Thus, observations suggest that the geomorphology and geo-morphometry of the glacier has a considerable control on the surface ice velocity of the glacier.
Accumulation zone
Glacier morphology
Glacier ice accumulation
Ablation zone
Tidewater glacier cycle
Glacier terminus
Glacier mass balance
Rock glacier
Cite
Citations (2)
Abstract Recent observations on Bjornbo Gletscher (lat. 71°., long. 25° W.), East Greenland, have revealed that it has several features characteristic of a surging glacier. One outstanding feature is the occurrence of drop-like ice masses in the lower part of the glacier which do not appear to belong to the main glacier. A detailed petrographic comparison between the morainic debris surrounding these drop-like ice masses and the rocks occurring in the upper part of the glacier has been made. The results indicate that these drop-like ice masses have been inserted into the main glacier. This drop-like form is explained as being due to ice transport from the side valleys, and this occurred over a short period of time during the movement (or surge) of the main glacier. Because of the highly variable rock types occurring in the respective accumulation zones, petrographic examinations of other moraines in the ablation zone have been used to trace them back to their respective firn fields. The main glacier and the tributary glaciers are today static. Bjørnbo Gletscher is therefore characterized by both static and moving phases, and its dynamics are the same as those of surging glaciers. The quiescent phase is estimated to have been about 100 years. The next surge will presumably occur around 1990,
Accumulation zone
Glacier morphology
Glacier ice accumulation
Glacier mass balance
Cirque glacier
Tidewater glacier cycle
Ablation zone
Cite
Citations (8)
Long-term series of observations on the glacier of the southern slope of Elbrus manifest the change of two climatic periods in the highlands of the Caucasus. During the first one, relatively cold and snowy period of 1982–1997 with a small positive mass balance, the Garabashi Glacier accumulated a layer of 0.8 m.e. The second period (1998–2017) is characterized by rising summer air temperatures and increasing precipitation in the first decade, and catastrophic melting in 2010–2017. The mass balance of the glacier averaged −0.63 m w.e. yr−1, and in some years it reached −1.00 ÷ −1.50 m w.e. yr−1. In the last ten years, frequency of vast anticyclones covering the southern part of the European part of Russia and the North Caucasus increased. Summer temperatures in the Elbrus region rose to almost the level of the 1950s that was the hottest decade of the XX century. Duration of the summer season on the glaciers increased. Active melting resulted in elevation of the equilibrium line of the Garabashy Glacier by 200 m. In the main part of the glacier alimentation area, i.e. at heights of 3800–4000 m, the large parts of the firn area had disappeared, but open ice of the ablation zone had appeared. The former areas of the "warm" firn zone, where up to 35% of melt water retained within the 20‑meter firn thickness, were replaced by the firn-ice zone, and the ice discharge increased. The glacier alimentation is decreased, and its tongue retreats with increasing velocity. Rocks and entire lava ridges release from ice at different levels of the glacier. The inter-annual variations of the glacier mass balance are controlled by intensity of ablation. In the second period, the correlation coefficient of these values reached 0.97 compared to 0.82 in the first one. In total over 36 years of observations, reduction of the glacier mass during the second period resulted in loss of volume (0.05 km3 or 14%), area (0.51 km2 or 11.4%), and of ice layer (11.4 m).
Firn
Accumulation zone
Glacier mass balance
Glacier ice accumulation
Anticyclone
Glacier morphology
Cite
Citations (15)
In this paper we present some results of studies of Southern Sygyktinsky Glacier, the largest glacier of Kodar Ridge. The glacier is located at altitude 2340–2690 m, its area is 0.48 km 2 and length 1.26 km. Firn line at the end of August was 2485±35 m. Since the end of Little Ice Age the glacier tongue retreated by 800 m and its area decreased by 0.44 km 2 (by 48%). Ice surface is asymmetric due to snow redistribution in local topography conditions. There are two ice formation zones on the glacier: firn-ice zone and superimposed ice zone. Snow cover on the glacier surface is thin and its chemical (ion) composition reflects atmospheric aerosol features and intensity of percolation processes. Air temperature measured over ice surface from 9.07 to 21.08 (every hour) varies from −1.5 to +18.0 ºC with mean value of 2.9 ºC. Summer balance in 2009 was estimated by value of 980 mm w.e. with positive-degree-day factor 5.1 mm ºC -1 day -1 .
Firn
Accumulation zone
Glacier ice accumulation
Glacier morphology
Glacier mass balance
Snow line
Snow field
Cite
Citations (4)
Glacier terminus
Accumulation zone
Tidewater glacier cycle
Glacier ice accumulation
Glacier morphology
Cirque glacier
Glacier mass balance
Cite
Citations (7)
Thinning
Accumulation zone
Glacier morphology
Glacier ice accumulation
Glacier terminus
Glacier mass balance
Rock glacier
Elevation (ballistics)
Cite
Citations (22)
From glaciological observations, we found spatial variation in the input of insoluble particles (ISP) on a glacier surface from atmospheric deposition and outcropping at the surface of the glacier by surface ablation at the ablation area of the Qaanaaq Ice Cap in northwestern Greenland. Possible sources of ISP input to the glacier surface were outcropping at the surface of the glacier by ablation at intermediate and low elevations, and from atmospheric deposition at high elevations. The annual atmospheric deposition of ISP was larger at high elevations than at intermediate and low elevations. The annual abundance of outcropping ISP was larger at intermediate elevations than at low elevations, where the annual ablation rate of the glacier surface was 1.5 times larger than at intermediate elevations. The ISP concentration in the glacier ice at intermediate sites was approximately 10 times larger than at low sites. The water stable isotopes of glacier ice at intermediate sites indicated that glacier ice at the intermediate sites did not form since the last glacial maximum, possibly the Holocene Thermal Maximum. Therefore, the accumulation of the ISP, which is outcropping at the intermediate site, occurred at high elevations after Holocene Thermal Maximum.
Accumulation zone
Ablation zone
Outcrop
Glacier morphology
Glacier ice accumulation
Glacier mass balance
Deposition
Tidewater glacier cycle
Ice core
Cite
Citations (4)
1. Introduction ( a ) The transition of firn into glacier ice; glacier structure Glaciers are divided into two main parts: the accumulation area, firn region or névé where the annual accumulation in the form of snow exceeds the loss by melting, evaporation and wind erosion, and the ablation area or glacier tongue. The dividing line between the two regions is called the Firn Line. Granular, compacted snow called firn covers the accumulation area. Its crystals are rarely larger than 2 mm. in diameter and are mixed with a considerable volume of air, so that the specific gravity is much lower than that of ice. The surface of the tongue consists of blue or glassy ice, more or less covered with rock debris; here the diameter of the ice crystals varies between 1 and 10 cm. or even more; the specific gravity of the ice is never far below 0.90. In summer the tongue has a bluish or grey appearance, while the firn region retains its white or whitish hue.
Firn
Accumulation zone
Glacier ice accumulation
Glacier morphology
Dome (geology)
Cite
Citations (56)
Abstract Fedchenko glacier is by far the largest glacier in the Pamir, Tajikistan. Owing to early accurate mapping of the glacier it is possible to evaluate glacier changes over eight decades, which is an exceptionally long time period for this remote mountain region. During this time a total volume loss of 5 km 3 was observed on the main trunk of the glacier, while the total area changed by only 1.4%. It is observed that the volume loss migrates from the lower parts of the glacier towards the upper ablation zone. The comparatively small change in area is a result of the supraglacial debris cover on the glacier tongue, which decouples the area loss from the volume loss to a considerable degree. The observed velocities of the glacier do not reflect the volume changes up to now because the interannual variability is larger than possible long-term changes so far. The intra-annual velocity distribution in the central ablation zone probably reflects the evolution of the basal drainage system. Based on ice thickness measurements and simple ice-dynamic assumptions, the total volume of Fedchenko glacier is 123.4 ± 8 km 3 .
Accumulation zone
Ablation zone
Glacier morphology
Glacier ice accumulation
Glacier mass balance
Cirque glacier
Ice caps
Cite
Citations (42)
We carried out a preliminary glaciological research on the No.31 Glacier in the Suntar Khayata Range, Sakha Republic, Russian Federation, in the summer of 2001. This glacier was intensively studied, including mass balance, ice temperature measurements and surveying, by Russian researchers in 1957-58 (the 3 rd International Geophysical Year) (Koreisha, 1963). We aimed to obtain the change of the glacier volume since 1958 to study climate change during the last 40 years, and to know the possibility of ice core drilling and analyses for paleoclimatic study in the eastern Siberia. The glacier is a valley-type cold glacier of approximately 3.85 km long and covers the altitude from 2728 m to 2050 m a.s.l. The accumulation area of the glacier is mostly underlain by superimposed ice, which is slightly capped with water-saturated firn. The ablation area is characterized by well-developed longitudinal foliations, and basal ice layers at the very end of the terminus. The air temperature was as high as 12.7 °C in average at the Base Camp (ca. 2000 m a.s.l.) during the observation period (July 21-27, 2001), and we observed intensive melting at the whole area of the glacier. From this observation, we conclude that the glacier is not suitable for the ice core study because it is probably difficult to reconstruct a continuous ice core climate record. Beside glaciological studies, we conducted a topographical survey of the glacier, which showed that the glacier terminus had retreated approximately 200 m in distance and lowered by approximately 20 m from 1957-59 to 2001.
Glacier morphology
Glacier ice accumulation
Glacier mass balance
Accumulation zone
Ice core
Firn
Cirque glacier
Tidewater glacier cycle
Glacier terminus
Cite
Citations (3)