Posts Tagged "flood"

The Chameleon Glaciers

Posted by on Apr 16, 2015 in Adaptation, All Posts, Featured Posts, Science | 0 comments

The Chameleon Glaciers

Spread the News:ShareCan you spot the glacier on the picture above? Not that easy… Glacier Noir is a debris-covered glacier located in the French Alps. Contrary to clean-ice glaciers which are shiny white or blue ice masses, debris-covered glaciers are ice masses with a layer of rock debris on the top which makes them look like their surrounding environment: they are the “chameleon glaciers”. They are currently called debris-covered glaciers but in the early 2000s, you could hear “debris-mantled glaciers” and even “buried glaciers” in the 1960s. They are often confused with rock glaciers. There are a lot of names and confusion around debris-covered glaciers. Why? Simply because they are difficult to find, define and study as you can imagine from the picture above. Debris-covered glaciers represent around 5% of all mountains glaciers in the world. So why is it important to study them – there are many more clean-ice glaciers, aren’t there? Yes, debris-covered glaciers are a small fraction of all glaciers but like any other glacier, the melting of debris-covered glaciers contributes to sea level rise and there is currently huge uncertainty about how fast they melt compared to clean-ice glaciers. In addition, in the Himalayas, they make up a greater proportion of the glaciers and in many valleys, debris-covered glaciers are the main and often the only source of drinking water, like for example the famous Khumbu Glacier just below Mount Everest on the Nepal side. Some debris-covered glaciers, like the Tasman Glacier, the biggest glacier in New Zealand, are very large features that can be the origin of risks and hazards. The debris layer creates numerous ponds filled with meltwater on the surface of glaciers. These ponds can hold monumental volumes of water that can be suddenly and brutally drained through crevasses in the ice or a breach on their edge. This drainage can create an outburst flood and submerge the valley below. Debris layers on top of glaciers can come from rock falls, like for the Sherman Glacier in Alaska. This rock cover modifies the dynamics of the ice by slowing down the melting happening underneath. This insulation process creates various phenomena, like thickening of the ice under the debris, building hills of ice slowly moving down the glacier or advancement of the glacier’s tongue. These two phenomena can block or deviate water streams and again generate massive floods. A less obvious reason to study debris-covered glaciers is that if glaciers on Mars exist, they are debris-covered. So studying debris-covered glaciers on Earth can contribute to space conquest and the human adventure on Mars. In the same vein, studying current debris-covered glaciers and their behavior in the face of climate change can help us understand and interpret the climate of the past. There is an example of a potential misinterpretation of the Waiho Loop moraine in New Zealand in front of the Franz-Joseph Glacier: 12000 years there was a worldwide cooling event (called Younger Dryas) that might have led to the formation of the very large moraine of Waiho Loop. Or, a massive rock avalanche landing on Franz-Joseph Glacier triggered its advance and the deposition of the moraine. I’ve already described a few examples of debris-covered glaciers: Glacier Noir, Khumbu Glacier, Tasman Glacier, Sherman Glacier and maybe Franz-Joseph Glacier. But where else can you find debris-covered glaciers? They can actually be found in every mountain range: from the Miage Glacier (Italy) in the European Alps with  to the Inylchek Glacier (Kyrgyzstan) or Langtang (Nepal) glaciers in the Asian High Mountain; from the Black Rapids Glacier (Alaska) in the Rocky Mountains and the Dome Glacier (Canada), to the Andes...

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Bhutan’s Fortresses Yet Another Victim of Glacial Floods

Posted by on Nov 11, 2014 in All Posts, Communities, Experiences, Featured Posts | 0 comments

Bhutan’s Fortresses Yet Another Victim of Glacial Floods

Spread the News:ShareTwo decades ago, a glacier lake outburst flood (GLOF) at Lugge Tso, a lake in central Bhutan, coursed down a river valley, killing 17 people, destroying 730 hectares of fields and pastures, and washing away four bridges. Most prominently in the minds of Bhutanese, it also damaged a dzong—a set of culturally significant buildings—in the town of Punakha. The flood was big news throughout the Himalayas, and concern about the decade-long reconstruction, financed principally by the governments of Bhutan and India. Today, glacial lake outburst floods are becoming a bigger hazard in the Himalayas and around the world, as glacial melt compromises the integrity of glacial lakes. These GLOFs threaten human lives, infrastructure and ecosystems. On a trip to Bhutan, I recently stayed in the town of Lobesa, which neighbors Punakha, and visited the site of the dzong to get a better understanding of the impact that the giant GLOF had on the community and its infrastructure. Dzongs are the most dramatic element of traditional Bhutanese architecture. They are massive fortresses, most of them located on hillsides, with high defensive walls and a tall interior watchtower. Within these walls are courtyards which hold administrative offices and temples, as well as many rooms for residences and storage which allowed residents to withstand a long siege. Though a few dzongs are recent, most date back to the last three or four centuries, when regional lords battled each other, and when armies from Tibet or India would invade Bhutan. As we neared Punakha, the driver stopped at the standard spot where tourists and Bhutanese alike take photographs of the dzong. From this vantage, the viewer can see how the dzong stands high above the confluence of two rivers. The driver explained that the wider Po Chhu to the east—the one that flooded–is male, and the smaller Mo Chhu to the west is female. Like its counterparts that dot the country, the Punakha dzong has religious and historic associations. Guru Rinpoche, the figure who brought Buddhism to Bhutan in the 8th century, foretold that someone with the name of Namgyal would someday travel to a hill shaped like an elephant. Centuries later,  Zhamdrung Namgyal, the leader who unified Bhutan into a single kingdom, saw the hill where the dzong is located, and noted that its elephant-like form, with the strip of land between the Po Chhu and Mo Chhu resembling the animal’s trunk. Zhamdrung, who defeated an invasion from Tibet, constructed the dzong in the 1630s and it has retained its importance to the present. The dzong was the seat of the government of Bhutan until the capital was moved to Thimphu in 1955 and the wedding of the present king was held there in 2011. I took the whole morning and part of the afternoon to explore the fortress. The first courtyard holds an enormous chorten (a Buddhist stupa) and a beautiful specimen of a Bodhi tree, the kind of tree under which Buddha achieved enlightenment. In one corner with government offices, county representatives were attending a meeting on budgeting procedures. People would come out of the meeting to make phone calls and send text messages. Evidently there is good cell coverage inside the dzong. At the other end of the courtyard, on the side near the Po Chhu, was a small shrine, the only one that was not located inside a temple and, as a consequence, the only one that I could photograph. (Red-robed monks were on the alert to prevent tourists from sneaking pictures of the images of Buddha, Guru Rimpoche and other religious figures inside the temples.)...

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As Glaciers Melt, A Lake in Nepal Fills Up

Posted by on Oct 22, 2014 in All Posts, Communities, Featured Posts, Science | 0 comments

As Glaciers Melt, A Lake in Nepal Fills Up

Spread the News:Share  Glaciers on Nepal’s Imja Tse (Island Peak) in the Himalayas have melted at an average rate of almost 10 meters per year over the past several decades, during which time residents of Imja Tse Valley below have literally watched the residual waters create an entirely new lake. The Imja Tsho (Imja Lake) first began collecting glacial meltwater in the 1960s, when it had a surface area of approximately 49 square kilometers. By 2007, it had grown to 945 square kilometers, an almost 2,000% increase. The aggressive rate of growth has residents and scientists worried about the threat of glacial lake outburst floods (GLOFs). The Himalayas are often considered the earth’s “third pole,” given that they contain more ice than anywhere else in the world besides the ice caps in the Arctic and Antarctica. Glacial retreat in this region is also happening faster than anywhere else in the world. According to a study released earlier this year by the Chinese Academy of Sciences, glaciers on the Tibetan Plateau have shrunk by 15 percent in the last three decades to 43,000 square kilometers. The melt has been almost unanimously attributed to human-induced climate change. In recent years, some organizations have found themselves in hot water for overstating the degree of melting at the Himalayan glaciers. In 2007, the United Nations’ Intergovernmental Panel on Climate Change, a scientific body made up of thousands of scientists and researchers, issued a report that claimed Himalayan glaciers could completely melt away by 2035. Three years later, IPCC officials issued a statement that said those original estimates were unfounded. (An op-ed appearing in April in Scientific American pointed out the seriousness of such overstatements.) And yet, despite the “Himalayan Blunder,” scientists still believe that by the time global temperatures increase by just 2 degrees Celsius, more than half of the Himalayan glaciers will have vanished. GLOFs like the ones threatening the Imja Tse Valley are an increasing concern worldwide, and the Himalayas, with so much melting ice, are particularly at risk. Glacial lakes are not a new or human-induced phenomenon, however conditions become unstable when these lakes form quickly in cracks and valleys previously covered in ice. It is often unclear whether the walls of the lakes are made of rock or melting ice, which heightens the risk of flooding and landslides. Many residents of the towns and villages scattered on the foothills of Himalayan glaciers, have already fallen victim to floods, avalanches, and mudslides caused by GLOFs. These disasters can result in loss of life and property, damaging essential infrastructure, destroying crops and crop land itself, and sometimes laying waste to entire villages, leaving only inhospitable rock and mud behind. For these reasons, there has been increasing attention to monitoring new and expanding glacial lakes in the region. In 2011, the Mountain Institute organized a team of 30 scientists from around the globe to study the Imja Tsho, and concluded that the lake does, in fact, pose a potential threat to local communities. They estimated that melting ice under the moraine could trigger a huge flood,  and that meltwater could seep through the hills around the lake, potentially causing a hill to collapse. They also warned that as melting continues, ice avalanches could tumble into the lake, causing a giant wave to deluge downstream communities. Last year, scientists from the High Mountain Glacier Watershed Program returned to Imja to discuss with village leaders the risks the lake poses and come up with a plan of action. They determined that there were three options: accepting the risk of a possible GLOF; relocating lodges and other structures to higher elevations to avoid flood damage; or an engineering solution, “such as...

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Flooded with memories in Nepal

Posted by on Sep 3, 2014 in All Posts, Communities, Experiences, Featured Posts | 0 comments

Flooded with memories in Nepal

Spread the News:ShareI was born and raised in Kathmandu but Monzo has always been the place I call home. Monzo is where my paternal grandmother spent all of her life tending our fields and looking after our ancestral home. Monzo is also the place where my father was born and raised until he left for Kathmandu to attend school. I visited Monzo with my brothers every year during our school breaks. From my village in Monzo in the Sherpa region in northeastern Nepal, we need to walk at least a day, depending on how fast we go, to get close to the glaciers higher up in the mountains. Because we can’t see the glaciers until we get closer to them, we don’t talk much about them. But we sometimes talk about glacial lake outburst floods (GLOFs). In 1985, the year I was born, a high mountain lake, Dig Tsho, flooded. Although the flood came long time ago, I know about it from the stories I have heard throughout the years. My father always talked about it as we passed through the scars from landslides and the places where there were once villages, including my maternal grandmother’s natal village. Often times, growing up, I would hear my grandparents say that some things are nomdok (inviting misfortune). Talking about bad experiences like the Dig Tsho GLOF was definitely one of them. It destroyed houses and fields, took lives and caused great distress. So, talking about GLOFs is not the most appropriate cultural thing to do from my grandparents’ perspective. But it is my hope that having conversations about them will let us prepare for an uncertain hazard-prone world of changing climate and bring us good karma in the long run. After finishing high school in Nepal, I left the country to continue my education. Several years later, I returned to the Sherpa region to conduct research for my dissertation at an American university. During that time, I asked my aunt—actually a friend of my parents from Monzo who I called “aunt” –whether I could interview her about her experience with the Dig Tsho flood. She agreed to talk with me, but at first did not remember the event. She had not spoken about the big flood with anyone for many years, because it had happened far in the past, and there was no need to recall those stressful moments of her life. But when I persisted in asking about the big flood that came many years ago when she was young, she opened up. She was with her mother in their potato field weeding the bean plants when she heard loud noises that sounded like the thunder that lightning produces. She said, “I remember the villagers calling us to come up and see what was going on on the other side of the Dudh Koshi [the major river in the region]…It was like a movie. People were running up the hill as the water below engulfed trees and rocks…so fast.” Unlike other villages in Pharak in the central part of the Sherpa territory, Monzo is not close to the Dudh Koshi, which is fed by the mountain glaciers up north including Dig Tsho to the left and Imja Tsho to the right. So, my aunt and her family were safe but they were terrified by the experience. After the flood, her family and neighbors took shelter under a giant rock and stayed for several hours. Under the rock, they cooked potatoes, shared tales of what they saw and heard. They returned home only when the night came. Nowadays, many people in...

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In Kyrgyzstan, not all glacier lakes are monitored equally

Posted by on Jul 24, 2014 in All Posts, Communities, Featured Posts, Policy and Economics | 0 comments

In Kyrgyzstan, not all glacier lakes are monitored equally

Spread the News:ShareAs the temperature rises and glacial lakes grow, the Kyrgyzstan government is monitoring some glaciers while neglecting others. Kyrgyzstani officials are closely studying the 18 growing glacial lakes on the Adygene Glacier to predict glacial hazards. Since these glacial lakes are located above Kyrgyzstan’s capital, Bishkek, glacial lake outburst floods could potentially flood the valley, endangering a million people. As glaciers are retreating, glacial lakes are growing and forming. This poses the risk of a glacial lake outburst, a kind of megaflood that occurs when dams holding back glacier lakes fail. Incidences of glacial lake outbursts are increasing. In 2007, the United Nations Environment Program classified floods from glacial lakes as the largest and most extensive glacial hazard with the highest potential for disaster. An additional threat comes from the underground ice plugs that dam these lakes. These plugs thaw slowly, feeding water into the Ala-Archa River. But a sudden melting could create an outburst of water and develop into a large, destructive mudslide and debris flow. In recent history, glacial lake outbursts have already impacted Central Asia. In 1998, one such event claimed more than a hundred lives in Batken Province in western Kyrgyzstan. In 2002, an outburst at Tajikistan’s Pamir Mountains claimed 23 lives. In both cases, early warnings of floods were not available. If a similar disaster occurred on the Adygene Glacier, many thousands of lives could be claimed, since the capital downstream is densely populated. Today, the Kyrgyzstani government is closely monitoring the glacial lakes above Bishkek and preparing organized emergency plans for evacuation. The government has allocated $15 million to build a drainage channel and automatic monitoring stations. When the sensors detect a critical increase in the water level, they trigger alarms in the valley to warn people to flee to safer ground away from the river valley. The government has not allocated resources equally for all hazardous glacial lakes in the country. Officials blame the unequal monitoring on the lack of government funds. In particular, there is no monitoring in the southern province of Osh, which has a population of one million. The province has been scarred with ethnic tension between the Kyrgyz and Uzbeks. Kyrgyz make up 68 percent of the population and Uzbeks account for 30 percent. Over the years, the conflict cost thousands of lives on both sides. After the 2010 Osh riots, Uzbeks have been strategically disenfranchised and internally displaced by the dominant Kyrgyz who dominate the government. Disputes over natural resources, land and water could easily escalate ethnic violence. The lack of preparation for glacial lake outburst floods creates a risk of a disaster that could worsen the existing ethnic tensions. Glaciologists predict glacial lakes will continue to around the world. Developing monitoring systems for glacial lakes near glacier communities is necessary to prevent massive loss. These initiatives should extent to all communities regardless of their economic, political or ethnic status. Spread the...

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