The Devdoraki Glacier in the Georgian Caucasus Keeps Collapsing

On May 17, 2014, a catastrophic rock-ice avalanche and glacial mudflow took place in the Tergi (Dariali) gorge, blocking strategic infrastructure in Georgia. The disaster resulted in the death of nine people. About 200 people were evacuated by helicopter from a border crossing checkpoint and nearby areas. Glacial mudflow destroyed the Trans-Caucasus gas pipeline, Dariali Hydropower Plant, and an international road connecting Georgia and Russia. This event inflicted several tens of millions of Georgian lari in damages to the country’s budget.

Sequences of the collapse

According to archival data, at least six ice and ice-rock avalanches fell from the Devdoraki Glacier onto the Tergi River valley during the period 1776-1876, the two largest occurring on June 18, 1776 and on August 13, 1832. The first blocked the Tergi River for three days and was breached catastrophically; the second was about 100 meters high and about 2 kilometers wide and blocked the Tergi River for 8 hours. After breaking the dam, the glacial muflow caused a great amount of damage to Vladikavkaz in North Ossetia, Russia.

Since 1832, several new blockages were forecasted, but either the ice-debris masses did not reach the Tergi River, or the forecasts failed altogether. For example, the Devdoraki Glacier advanced in 1866 and 1867, raising alarm and forcing researchers to monitor its position. But the ice debris developed slowly and the Tergi River was not blocked. Again, in 1876, there was a danger of a blockage since the glacier greatly increased and advanced by about 150 meters.

Scientists have published other observations of the Devdoraki Glacier, up to the first decade of the 20th century (Tielidze et al., 2019).

Latest investigation

I, along with several colleauges, published in April work that presents the sequence of the Devdoraki Glacier hazards and analyzes the latest collapse, which occurred on May 17, 2014.

An ASTER image from May 16, 2014 shows traces of relatively small rock fall, revealing instability in the glacier. (Figure 1a). The result of the disaster is shown on the Landsat image from July 11, 2014 (Figure 1b) and in the PLEIADES image from May 18, 2014 (Figure 1c).

Figure 1. a – ASTER image 16/05/2014; b – Landsat L8 image 11/07/2014; c – PLEIADES image 18/05/2014

The resulting mudflow into the Tergi (Dariali) Gorge blocked the Tergi River for several hours, creating a 20-30 meter-deep lake (Figure 2) with a volume of at least 150,000 cubic meters. The height the ice and rock debris fell from the glacier face to the gorge was about 3.2 km, while the distance was about 10.2 km.

We estimate that the leading face of the Devdoraki Glacier advanced about 180 m between 2014 and 2015, which was caused mostly by rock-ice avalanche deposits. This part of the glacier should countine to be monitored as it could heighten debris flow activity in the future.  

Figure 2. Tergi (Dariali) gorge, result of Devdoraki glacial-mudflow (17/05/14) (Source: Levan Tielidze).

Possible causes

We considered the main hypotheses behind these events, namely a) tectonic and seismic (Figure 3a), b) permafrost (Figure 3b), c) volcanic, and d) morphological factors; interpreted the data for mechanisms and velocities of the catastrophic movement, and argued that the 2014 event should not be classified as a glacier surge, althoughthe possibility of similar glacial surges can not be excluded.

Figure 3. a – Tectonic map of the study region (compiled by authors). b – Permafrost zonation index map

The Kazbegi-Jimara massif should be considered as a natural laboratory that enables the investigation of rock-ice avalanches and glacial mudflows.


We recommend to construct a road tunnel on the east (right) slope in the Tergi valley (Figure 1c) and to discontinue the Dariali Hydropower Plant construction in order to mitigate risk and avoid incidents including deaths in the future.

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Glacier change in the Georgian Caucasus Mountains

From the Cryosphere: “Changes in the area and number of glaciers in the Georgian Caucasus Mountains were examined over the last century, by comparing recent Landsat and ASTER images (2014) with older topographical maps (1911, 1960) along with middle and high mountain meteorological stations data. Total glacier area decreased by 8.1±1.8% (0.2±0.04%yr−1) or by 49.9±10.6km2 from 613.6±9.8km2 to 563.7±11.3km2 during 1911–1960, while the number of glaciers increased from 515 to 786. During 1960–2014, the total ice area decreased by 36.9±2.2% (0.7±0.04%yr−1) or by 207.9±9.8km2 from 563.7±11.3km2 to 355.8±8.3km2, while glacier numbers decreased from 786 to 637. In total, the area of Georgia glaciers reduced by 42.0±2.0% (0.4±0.02%yr−1) between 1911 and 2014. The eastern Caucasus section had the highest retreat rate of 67.3±2.0% (0.7±0.02%yr−1) over this period, while the central part of Georgian Caucasus had the lowest, 34.6±1.8% (0.3±0.01%yr−1), with the western Caucasus intermediate at 42.8±2.7% (0.4±0.03%yr−1).

A view of the Caucasus Mountains, Svaneti, Georgia. (Credit: Wikimedia Commons/sv:User:Ojj! 600)

Glacial lake expansion on the Tibetan Plateau

From Society & Natural Resources: “Global climate change is causing the majority of large lakes on the Tibetan Plateau to expand. While these rising lake levels and their causes have been investigated by hydrologists and glaciologists, their impacts on local pastoral communities have mostly been ignored. Our interviews with pastoralists in central Tibet reveal their observations and beliefs about Lake Serling’s expansion, as well as how its effects are interacting with current rangeland management policies. Interviewees reported that the most negative effects on their livelihoods have been reduced livestock populations and productivity due to the inundation of high-quality pastures by saline lake water. However, pastoralists’ collective efforts based on traditional values and norms of sharing, assistance, and reciprocity have helped them cope with these climate change impacts. These local, traditional coping strategies are particularly worthy of attention now, given that the transformation of traditional pastoralism is a goal of current government development initiatives.”

The Himalaya seen from the International Space Station. (Source: Wikimedia Commons/NASA)

An early warning plan for Ecuador

From the International Federation of Red Cross and Red Crescent Societies: “This Early Action Plan aims to establish appropriate early action using volcanic ash dispersal and deposition forecasts that benefit the most vulnerable families in the most potentially affected areas. Ecuador is a country that is under the influence of several natural hazards due to its geographical location, atmospheric dynamics and geological characteristics. The country has historically faced several important events such as floods, water deficit, earthquakes, volcanic activity and landslides, among others, which leave thousands of people affected and generates millions of dollars in losses.”

A view of Ecuador’s glacier-covered volcano Cotopaxi. (Source: Wikimedia Commons/Gerard Prins)

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Avalanche Strikes Near Russian Glacier

People peering into a crevasse on the Greater Azau Glacier (Source: Mauri Pelto/From a Glaciers Perspective).


The rust-colored snow on the glaciated peak of Mount Elbrus in the Russian Caucasus unveiled its bright white interior when it came tumbling down the mountain toward a ski resort parking lot on March 24.

Most snowstorms in this region do not lead to avalanches. The trigger in this case was the accumulation of meltwater, which made the snow heavier and more prone to falling.

The avalanche covering dozens of cars as it makes its way down the slope of Mt. Elbrus (Source: ViralHog).

The avalanche did not cause any deaths or injuries, but it did cover at leastt a dozen cars that stood in its path. The blaring car alarms and rumble of the snow can be heard in the background of several videos taken from the parking lot. Some people on the automotive website Jalopnik questioned whether the avalanche was “evidence that Mother Nature is claiming revenge for climate change by consuming these internal combustion vehicles.”

The avalanche on Mt. Elbrus (Source: lagonaki).

The unusual color of the snow had made headlines in recent days, bringing international attention to the remote glacial area.

Stanislav Kutuzov, head of the Department of Glaciology at the Institute of Geography at the Russian Academy of Sciences in Moscow, told GlacierHub that the “atmospheric front of March 22 to 24 brought large amounts of precipitation together with dust from the Libyan desert.” The dust, from North Africa, reached the Caucasus Mountains on March 23, one day before the avalanche.

“A large number of particles were scavenged from the atmosphere by the precipitation which resulted in yellowish/red colored dust deposition in the region,” Kutuzov explained.

The discolored snow is not unusual for the region, which has experienced similar events over the past several years. Kutuzov added that “dust transportation from the Sahara is less frequent but results in higher dust concentrations.” The evidence of this can be seen in ice cores taken from Mt. Elbrus.

Mount Elbrus, at an elevation of 5,642 meters (Source: Sausruqo/Twitter).

Although the timing might seem to suggest the dust instigated the avalanche event, the dust didn’t influence the avalanche directly, according to Kutuzov. Wet avalanches are typical for this time of the year in the Caucasus, he said. In the days leading up to the event, warm conditions had dominated the area, causing substantial melting and the subsequent avalanche.

The avalanche originated from a peak, which is located at an elevation of 2,300 meters and known for the Greater Azau Glacier. The ski resort is a jumping off point for people who climb the mountain on the southern slopes of Mt. Elbrus.

Similar to other glaciers in the area, Azau Glacier is retreating. The rate of retreat has increased in recent years, but it still has an extensive accumulation zone, where snowfall gathers.

The avalanche characteristics of the Azau glacier and Mt. Elbrus are not unfamiliar to the ski resort management and others nearby. “This avalanche is well-known, and happens almost every year,” assures Kutuzov. The area had previously installed snow nets to protect from avalanches such as this one, but a wet avalanche of this volume was more than this safeguard could handle.

Catch a view of the avalanche as it took place below— a reminder of the importance to take care around glaciers, even retreating ones.

Tracing the Glaciation of the Greater Caucasus Mountains

In a paper published last month in the Open Journal of Geology, four researchers from the Ivane Javakhishvili Tbilisi State University of Georgia traced the old glaciation of the Caucasus Mountains from the 17th to 19th century during the Little Ice Age. These mountains are the highest mountains in Europe. Despite being remote, studying their processes can aid in the understanding of global climate history.

In this study, it is remarkable that the team had a robust methodology comprising a rigorous review of local knowledge and sources from the indigenous people as well as the analysis of rock samples collected during their expeditions. Reading a collection of folklore from the mountain communities by A. Krasnov, the team was able to reconstruct the advance of local glaciers that stretched all the way down to the populated mountain valleys during that epoch. This collection served as a first-hand account on the extent of glaciation based on the location of the villages.

Map of Caucasus Mountain Range
Map of Caucasus Mountain Range (Source: Wikimedia Commons).

Divided into the Greater Caucasus in the North and the Lesser Caucasus in the south, the Caucasus mountain region in West Asia stretches between the Black Sea and Caspian Sea. It is formed from the tectonic plate collision between the Arabian and European plates, occupying territory in Georgia, Armenian, Azerbaijani, Russia, Turkey and Persia. According to a local Georgian Svanetian poem by Nizardze, glacier advances had reached a distance of up to 17km during the peak of the Little Ice Age.

The existence of Russian topographic maps from the second half of the 19th century also helped form a broad picture of the latest glaciation. This knowledge was then further corroborated with other sample data collected in the team’s expedition.

The first technique used was petrography, which is the classification of rocks based on physical structure and mineral content. Present-day block debris from moraines could be reconstructed with this information to find out their main centers and from thereon, historical glacier movement and distribution boundaries.

The second technique used was palynology, which is the study of microscopic matter. It was used to identify the genesis of loose sediments from moraines. Using 590 pollen samples, the fossilized plant spectrum in the loose sediments were analyzed to explore if weathering of the moraines occurred as a result of glaciation or fluvial action and the time periods they occurred in. Information about whether the rocks were covered in ice at that point in time would allow researchers to estimate the extent of glaciation.

The summit of El Ushba, a peak in the Georgian Caucasus Mountain Region
The summit of El Ushba, a peak in the Georgian Caucasus Mountain Region (Source: Inakimiro/ Instagram).

“The glaciers completely filled the river valleys of the Greater Caucasus, passed the foothills and covered some of the piedmont valleys. It is supposed that the strongest glaciation took place in the Terek (the northern slope) and Kodori (the southern slope of the Greater Caucasus) river basins as well as in the Enguri and Rioni basins,” the research notes.

Until today, the actual mudflow activity in the Caucasus is still rather intensive (especially in the east). However, it appears that in the past it was even more intensive due to the tectonic shoves, rock falls and catastrophic thaw of large glaciers during highly dynamic glacial epoch. Based on the traces of glaciers, the Caucasus ancient snow-line is still about 700 to 1000 meters lower than the contemporary one.

Research suggests that the minor glacial epoch experienced by the Caucasus Mountains was intensified by the South European covering glaciation. However, the team believes that atmospheric circulation processes and regional tectonic movements are the main drivers of the glaciation.

The Little Ice Age remains the heart of geological research in the Caucasus Mountains since it is the last stage of glacial advance in the region. Hence, the geological mystery on the relative importance of the drivers for minor glacial epoch is still being debated.


Photo Friday: 19th Century Russian Paintings of the Caucasus

A number of 19th century Russian artists painted landscapes of the Caucasus. They were fascinated with the region’s rugged mountains— many of them topped with glaciers— and its wild, exotic, fierce inhabitants. The paintings often evoke, directly or indirectly, the wars which ran from 1813 to 1864 in which the Czarist armies displaced the Persian rulers of this region and subjugated the native populations. But the paintings do not simply celebrate Russian conquests. Instead, they underscore the heroism and endurance of the fighters on both sides. Seeking to impress viewers with the dramatic mountains, the artists often exaggerated the height and form of the mountains.

Many of the artists were radicals who opposed the rigid hierarchies of Czarist Russia. Some of them traveled to the Caucasus as exiles from the major Russian cities of Moscow and St. Petersburg. Among these was the Romantic writer Mikhail Lermontov, known for his poetry and his early novel The Hero of Our Age, and who also produced landscape paintings (the first in the series below is one of his). He was exiled twice, the first time for writing a poem critical of high officials, the second for insulting another publicly.

Other artists had rebelled against the major artistic institutions of Czarist Russia, and the formalism that these institutions promoted. Several of the paintings included below were produced by members of the group The Wanderers, students who left the Imperial Academy of Arts, located in St. Petersburg, in 1863 in frustration at the academy’s deliberate lack of attention to Russian culture. They dedicated themselves to depictions of daily life, showing common people, often in outdoor settings.

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More 19th century Russian paintings of the Caucasus, many of them depicting glaciers, can be found here.

Georgia: Glaciers and Geopolitics

A glacier flows down a gorge between two peaks in the Caucasus Mountains. Source: Flickr, Pavel Karafiat.
A glacier flows down a gorge between two peaks in the Caucasus Mountains. Source: Flickr, Pavel Karafiat.

Glaciers in the Republic of Georgia have seen a 16 percent decline over the last 150 years, according to a new chapter in the World Regional Geography Book Series which describes this country, located in the Caucasus Mountains. The melting of glaciers has also resulted in fragmentation as larger glaciers are broken up into smaller ones (786 glaciers occupy a total area of 550 square kilometers). These changes may have important implications not only for the geology of the Caucasus Mountains but for the thousands of Georgians whose lives intersect with glaciers, authors of the chapter stated.

Georgia occupies a disproportionate share of headlines in the world for a country with a population of 3.7 million and a land area of 640,000 square kilometers; it is slightly more populated than Connecticut and slightly larger than Florida. Ethnic and geopolitical tensions are high, and the country was briefly at war with Russia in August of 2008 over the status of South Ossetia. In 2003, the country underwent a “Rose Revolution,” which saw the end of 30 years of rule by the country’s Soviet-era leader and was accomplished by peaceful means.

A tower constructed in the European Dark Ages in the northwestern province of Svanetia. Source: Wikipedia
A tower constructed in the European Dark Ages in the northwestern province of Svanetia. Source: Wikipedia

While the political process has improved stability and confidence in the Georgian government, the country is still subject to the geopolitical demands that arise from its unique location. Together with Azerbaijan and Armenia, it forms a barrier between Russia and the Middle East that stretches from the Caspian Sea in the east to the Black Sea in the west. Oil from the Caspian Sea must pass through Georgia in order to reach western markets via the Black Sea and the Mediterranean.

While recent geopolitics have involved the Russia, Turkey and Azerbaijan as key neighbors, the area has a more ancient history that is very rich. As it lies in such a key area, it was vied over by forces including, in relatively recent times, the Russian Empire, and in relatively ancient times the Persian and Byzantine Empires. Ancient artwork and archaeological features abound in areas such as Svaneti, a province in the northwest of Georgia.

As Georgia pursues an independent path, it must manage the challenges of climate change which will accelerate glacier loss and impact its citizens, the authors wrote. In 2007, the trans-Caucasus highway was shut down after 35 avalanches in one day covered them with snow and debris. Resettlement programs are one part of the solution. 8,500 people have been moved out of harm’s way since 1987, a year in which a record snowfall, continuous over 46 days, left snow that reached 16 meters in depth in some areas.

Rock forms left behind in a stream by the Challadi Glacier. Courtesy of Flickr user Orientalizing.
Rock forms left behind in a stream by the Challadi Glacier. Courtesy of Flickr user Orientalizing.

One mechanism by which glaciers in this area contribute to avalanches is a phenomenon known as glacial surge, which is a sudden slide by the leading edge of the “river of ice” that is a glacier. This can be triggered by a change in glacier slope, which frequently occurs in the jagged Caucasus Mountains. The glacial surge can send chunks of the glacier’s rock and ice crashing down a slope and into populated areas. Just over the border on the Russian side of the Caucasus, this sort of slide by the Kolka glacier is believed to be the cause of a 2003 avalanche that killed 125 people. Avalanche risks spread throughout Georgia, which has mountains along both its northern and southern borders, though the eastern portion of the country has a slightly larger share of the at-risk area.

Though glaciers pose risks to people who live near them, they also play an important role in defining the area they live in. The remarkable geography that can be seen on the slopes of the Caucasus Mountains, including rock formations and polygonal land shapings, come about through peri-glacial processes, whereby glaciers carve and reshape the land as they pass over it. Keeping Georgian citizens safe fro the dangers that these dynamic glaciers ring is a daunting challenge that this country faces as it pursues a path of self-determination.

Roundup: Yaks, Snow Algae, and Slime Molds

How do wild yaks respond to glacier melt and past exploitation?

Yak at Yundrok Yumtso Lake

“To explore how mammals of extreme elevation respond to glacial recession and past harvest, we combined our fieldwork with remote sensing and used analyses of ~60 expeditions from 1850–1925 to represent baseline conditions for wildlife before heavy exploitation on the Tibetan Plateau. Focusing on endangered wild yaks (Bos mutus), we document female changes in habitat use across time whereupon they increasingly relied on steeper post-glacial terrain, and currently have a 20x greater dependence on winter snow patches than males. Our twin findings—that the sexes of a cold-adapted species respond differently to modern climate forcing and long-past exploitation—indicate that effective conservation planning will require knowledge of the interplay between past and future if we will assure persistence of the region’s biodiversity.”

Read more about the article here.


Snow algae grows on glacier surface annually.

Snow Algae

“Snow algae in shallow ice cores (7 m long) from Yala Glacier in the Lang-tang region of Nepal were examined for potential use in ice-core dating. Ice-core samples taken at 5350 m a.s.l. in 1994 contained more than seven species of snow algae. In a vertical profile of the algal biomass, 11 distinct algal layers were observed. Seasonal observation in 1996 at the coring site indicated most algal growth occurred from late spring to late summer. Pit observation in 1991, 1992 and 1994 indicated that algal layer formation takes place annually.”

Read more about the article here.


Slime mold preys on bacterium under snow.

Slime Molds

“Abundance and habitat requirements of nivicolous myxomycetes were surveyed over 4 yr at the northwestern Greater Caucasus ridge (Russia). An elevational transect spanning 3.66 km from 1 700 to 3 000 m a.s.l. was established at the summit Malaya Khatipara situated within the Teberda State Biosphere reserve. Between 2010 and 2013 1177 fructifications of nivicolous myxomycetes were recorded, with 700 of these determined to 44 species, varieties, and forms. Virtually all fructifications developed near or at the margin of a snow field. Abundance of myxomycete fructifications varied extremely between years, ranging from near zero to hundreds of colonies. At sites with known myxomycete occurrences 16 data loggers were installed in the years 2011 and 2012, measuring relative humidity and temperature at the soil surface. Together with weather data recorded on the nearby Klukhor pass and experiments with myxamoebae cultured on agar, these data explain the observed extreme fluctuations in myxomycete abundance.”

Read more about the article here.

Dariali gorge may be in danger from new hydroelectric plant

The construction of a hydropower plant near Georgia's Dariali Gorge could endanger the surrounding landscape. (photo: Rita Willaert)
The construction of a hydropower plant near Georgia’s Dariali Gorge could endanger the surrounding landscape. (photo: Rita Willaert)

Along Georgia’s border with Russia, about two hours north of the Georgian capital of Tbilisi, the Tergi River flows on an almost 400 mile journey down from the Devdorak Glacier atop Mount Kazbek to the Caspian Sea. The river has been a valued source of water for the communities along its banks for thousands of years, and the gorge which it cuts through the Caucasus has been a key trade route as well.

It has recently become the site of a controversial hydroelectric project. After not one, but two major landslides, the Dariali Hydropower Plant, located on the river, has become a topic of recent debate. The May 2014 landslide left three power plant workers dead and five others missing, it also completely impeded the Dariali Gorge, cutting of the region’s arterial roadway between Georgia and Russia, in addition to severing an essential natural gas pipeline providing Armenia with natural gas from Russia. The August landslide, reportedly larger than the one a few months before, resulted in the death of two more hydroelectric plant workers and necessitated a visit to the area by the Georgian president.

These events are not new for the region, which has been blighted by landslides for as long as local history remembers. This history makes local residents concerned. Other hydroelectric projects have succumbed to such hazards. For this reason and others ,the Dariali project, which would provide an estimated 108 Megawatts of electricity to the region, has already run into political controversy. The public does not fully accept the project, Eighty to 90 percent of the Tergi River would have to be diverted, leaving almost five miles of the riverbed completely dry, and threatening the local trout population. The project necessitated the rezoning of the area, removing its status as a national park under legal protection. Local people were concerned that construction began before a permit was issued, or before even mandatory public hearings were held.

Another issue is contribution of global warming to the latest two landslides. Devdorak Glacier, like other glaciers in the Caucasus, has been retreating in recent years. The meltwater could lead to increased water flow and thus contribute to natural erosion, increasing the risk of floods and landslides. Such dangers are well-established in the valley, as demonstrated by accounts as far back as 1869. Douglas W. Freshfield gives this account in his “Travels in the Central Caucasus and Bashan“:

“M.E. Favre, of Geneva, a well-known geologist who visited the Devdorak Glacier a few weeks after ourselves, came to the following conclusion as to the nature of the catastrophe. No avalanche, he says, could without the aid of water traverse the space between the end of the glacier and the Terek (Tergi river), and he accounts for the disasters which have taken place in the following way. He believes the Devdorak Glacier, to which he finds a parallel in the Vernagtferner Glacier in the Ötzthal Alps, to be subject to periods of sudden advance. During these the ice finds no sufficient space to spread itself out in the narrow gorge into which it is driven, and is consequently forced by the pressure from behind into so compact a mass that the ordinary water-channels are stopped, and the whole drainage of the glacier is pent-up beneath its surface. Sooner or later the accumulated waters burst open their prison, carrying away with them the lower portion of the glacier. A mingled flood of snow and ice, increased by earth and rocks torn from the hillsides in its passage, sweeps down the glen of Devdorak. Issuing into the main valley it spreads from side to side, and dams the Terek. A lake is formed, and increases in size until it breaks through its barrier, and inundates the Dariali Gorge and the lower valley.” [ed: place names have been modernized from original text]

Only time will tell whether or not the Dariali Hydropower Plant will be realized, and if so, what the effects will be for the region. Looking back at recent history, however, the safety of the project itself and the valley below seems suspect at the least.

For more information about the Dariali Gorge landslide see:

For a related GlacierHub story see: