Glacier Lake Bursts in Bhutan

Upper drainage of Mochu, showing glacier lakes. (Source: Google Earth)
Upper drainage of Mochu, showing glacier lakes. (Source: Google Earth)

On the morning of Sunday 28 June, an earthquake in India caused a Glacial Lake Outburst Flood in northern Bhutan.  Local residents alerted officials, who activated warning systems and ordered evacuations downstream. Rivers  rose to high levels, but no fatalities occurred. By Monday night, the rivers had begun to fall.

Map of 27 June earthquake, courtesy of the USGS
Map of 28 June earthquake, courtesy of the USGS

The United States Geological Survey reported an earthquake of 5.5 on the modified Richter scale at 7:05 AM local time, at 17km north-northeast of the town of Basugaon, in Assam State, India and 22 km south of the town of Gelephu in  Sarpang District, Bhutan.

Light to moderate shaking was reported from Nepal and Bangladesh as well as Bhutan and India. Sonam Choden in Thimphu in western Bhutan reported on Facebook “the earthquake rocked my husband right back on to sleeping.” Sangay Wangchuk, who lives in Jakar in central Bhutan, wrote “Ap Naka wags its tail again.” Ap Naka means “father earthquake,” referring to the common belief that the earth is held by a giant male spirit whose movements cause earthquakes.

The immediate damage in Bhutan was negligible, and even in India it was slight. Three persons sustained minor injuries when an old wall collapsed near the railway station in Kokrajhar, Assam, injuring three people. At an ancient temple in Chirang district, Assam, a sculpture of a lion was knocked off its base.

A glacial lake, Lemthang Tsho, located about 95 km northwest of the epicenter, burst later that day. This lake, also known as Shinchila Tsho, is located in Laya County in Gasa District in northern Bhutan, close to the border with China.   According to Kuensel, Kinley Dorji, a county official  in Laya, stated that mushroom collectors in the high pastures near glaciers had called him to let him know about the outburst from the lake, which is one of the sources of the Mochu, a major river of Central Bhutan. He, in turn, alerted district officials in Gasa and in Punakha and Wangdue, two large districts downstream on the Mochu. He also spoke with police, hospitals and officials at a large hydroelectric station at Punatsangchu.

Flooding on the Mochu River, courtesy of Kuensel via Facebook
Flooding on the Mochu River, courtesy of Kuensel via Facebook

Officials at the three major gauges along the Mochu monitored the water levels closely. They began sounding the sirens around 6:30 pm, even before the rivers reached the level for alerts, because they were concerned about additional risks from the monsoon rains, which had been heavy during the preceding weeks. The sirens caused panic among many residents, and they were turned off after more than an hour. The Prime Minster ordered evacuations along the Mochu River and at the hydropower station at 9:30pm, and reports suggest that these were largely complete within an hour. Patients at a hospital close to the river were moved to a military hospital at higher ground.

The river peaked late that evening, with high waters at Punakha a bit before midnight and at Wangdue later on. Fortunately, the towns were not damaged. The historic fortress or dzong of Punakha had been partially destroyed by a glacier lake outburst flood in 1994, so residents were concerned. The residents returned to their homes the next morning. Power, which had been cut in Punakha, was also restored.

Teams traveled through the area on 29 and 30 June to examine the damage. They reported that six wooden bridges had been washed out, isolating some villages and Laya town, and impeding the assessment efforts. Several groups of mushroom collectors were stranded on the far side of the now-empty Lemthang Tsho lake.

Karma Dupchu , the chief of the Hydrology Division within Department of Hydrometeorology,  will send a delegation to the glacier lakes high in the Mochu drainage, to see which of them burst, and to assess the relative importance of the earthquake and the heavy rains in causing the flood.

Rebuilding efforts already began by 30 June, as shown by a tweet from the Prime Minister Tshering Tobgay

 

 

 

Nepali Villagers Trapped Under Threat of Glacier Floods

One month after the first of two major earthquakes in Nepal, 38 villages, 834 households and 4600 people continue to wait for substantial relief efforts and remain uncertain about the future.

The first earthquake, which hit on April 25, severely damaged villages in Pharak, in the southern part of the Everest region in Nepal. When the second earthquake hit on May 12, what remained of villages after the first quake was destroyed.

Woman stands in front of a makeshift shelter, salvaging her belongings. She is worried about how she would be able to provide for her family now that she cannot return to her home. (Photo by Pasang and Un Sherpa)
Woman in front of a makeshift shelter, salvaging her belongings. She is worried about how she will provide for her family now that she cannot return to her home. (Photo by Pasang and Un Sherpa)

Pharak lies within Chaurikharka Village Development Committee (VDC) – the local level administrative zone – in the Solukhumbu district. So far, the government of Nepal has not listed Solukhumbu as a priority district, and major relief operations have been largely absent.

In addition to experiencing continuous tremors, villagers in Pharak are also shaken by rumors of that Imja Tsho, a glacial lake upvalley from the village, could burst and flood villages below, as it had thirty years ago.

The thought of a potentially catastrophic flood wiping out villages continues to keep villagers away from their homes and gardens where they live in tents. On May 25, a sudden concern about a glacial lake outburst flood drove hundreds of villagers to higher ground, fearing for their lives. Though Imja Tsho did not burst, there are reports that another glacial lake may have released its waters, creating high river levels downstream. According to local sources, water levels on Imja Tsho appear safe as of May 26.

Immediately after the first earthquake, I traveled to Nepal, where I joined my husband Un Sherpa, a medical volunteer, and Krishna Bhetwaal, an engineer volunteer, on a visit to Pharak to assess the community’s needs.

I am an anthropologist. I was born and raised in Kathmandu, but I often visited my mother’s home village of Jorsalle in Solukhumbu, where we would stay with her mother, who lived there. I now live in the United States, where I teach anthropology at the Pennsylvania State University.

 Dr. Krishna Bhetwaal, engineer volunteer, and I assess damage caused by a falling rock inside a home in the village of Jorsalle. After the first earthquake a giant rock rolled into this house leaving a huge hole. After the second earthquake, this house is completely damaged and uninhabitable. (Photo by Un Sherpa)
Dr. Krishna Bhetwaal, engineer volunteer, and I assess damage caused by a falling rock inside a home in the village of Jorsalle. After the first earthquake a giant rock rolled into this house leaving a huge hole. After the second earthquake, this house is completely damaged and uninhabitable. (Photo by Un Sherpa)

When I returned to Nepal after the earthquake, I visited over 200 houses in 30 villages and found that help is urgently needed.

The villages of Jorsalle, Bengkar, Gumela, Thado Koshi and Chaurikharka, to name a few, have been severely damaged with nowhere for residents to live. Families are living in crowded, cold and wet temporary tarpaulin shelters, schools are struggling to stay open, and health posts are waiting for medical supplies and staff.

To date, villagers have received tarpaulins, tents, rice, oil, salt and some cash from multiple sources. All of this, however, remains insufficient. In the region, the supplies – which have come in groups of tens or hundreds – are not enough to help the thousands in need.

Based on our assessment, there are two most vulnerable groups. The first group is the families of migrants who came to Pharak from other regions looking for better economic opportunities, and the second is the economically disadvantaged families, who did not have much to begin with even before the earthquake. Both of these groups are unseen, voiceless and without strong social networks to rely on.

DSC_3139
House in the village of Rangding. (Photo by Pasang and Un Sherpa)

In the absence of major relief efforts and attention to the region, community members have stepped up to volunteer and exhausted their limited financial and social capital. Neighbors are lending blankets and food, while they themselves sleep outside in cold makeshift shelters. Community members are donating their own money and putting together impromptu relief efforts to help one another.

It is clear that in order to recover from this disaster and rebuild in a sustainable way, the efforts of many will be needed.

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Roundup: Irrigation, Monitoring, and Tidewater

Evolution of Socio-hydrological Interactions in the Karakoram 

Hunza People (Source: Jordi Boixareu/Flickr)
Hunza People (Source: Jordi Boixareu/Flickr)

“Based on three case studies, this paper describes and analyzes the structure and dynamics of irrigation systems in Upper Hunza, located in the western Karakoram, Pakistan. In these deeply incised and arid valleys, glacier and snow melt-water are the primary water sources for agricultural production. The study shows how glacio-fluvial dynamics impact upon irrigation systems and land use practices, and how, in turn, local communities adapt to these changing conditions: framed here as socio-hydrological interactions. A combined methodological approach, including field observations, interviews, mapping and remote sensing analysis, was used to trace historical and recent changes in irrigation networks and land use patterns.”

Read more about this paper.

 

Glacier Dynamics Monitoring in Kyrgyzstan

Inylchek Glacier Source: Oleg Brovko/Flickr)
Inylchek Glacier (Source: Oleg Brovko/Flickr)

“The German Research Centre for Geosciences (GFZ, Potsdam, Germany) and the Central-Asian Institute for Applied Geosciences (CAIAG, Bishkek, Kyrgyzstan) jointly established the Global Change Observatory “Gottfried Merzbacher” at the Inylchek Glacier in eastern Kyrgyzstan which is one of the largest non-polar glaciers of the world and consists of two glacier streams. The flow of melt-water from the northern tributary forms a lake (Lake Merzbacher) that is dammed by the calving ice front of the southern Inylchek Glacier. At least once a year a glacial lake outburst flood (GLOF) occurs and the complete water of the Lake Merzbacher drains through sub-glacial channels. To monitor the glacier dynamics including the post-drainage ice dam response, a small network of remotely operated multi-parameter stations (ROMPS) was installed at different locations at the glacier.”

Read more about this paper.

 

The Largest Non-polar Tidewater Glacier in Alaska

Hubbard Glacier Source: Robert Raines/Flickr)
Hubbard Glacier (Source: Robert Raines/Flickr)

“Hubbard Glacier, located in southeast Alaska, is the world’s largest non-polar tidewater glacier. It has been steadily advancing since it was first mapped in 1895; occasionally, the advance creates an ice or sediment dam that blocks a tributary fjord (Russell Fiord). The sustained advance raises the probability of long-term closure in the near-future, which will strongly impact the ecosystem of Russell Fiord and the nearby community of Yakutat. Here, we examine a 43-year record of flow speeds and terminus position to understand the large-scale dynamics of Hubbard Glacier. Our long-term record shows that the rate of terminus advance has increased slightly since 1895, with the exception of a slowed advance between approximately 1972 and 1984. The short-lived closure events in 1986 and 2002 were not initiated by perturbations in ice velocity or environmental forcings, but were likely due to fluctuations in sedimentation patterns at the terminus.”

Read more about this paper.

PhotoFriday: GlacierHub Writer Supports Nepal Recovery

© IOM 2015
© IOM 2015

On April 25, 2015, a catastrophic earthquake rattled Nepal killing over 8000 people and leaving hundreds of thousands homeless. Areas of Nepal continue to remain unstable as a result of continuous landslides. According to the International Centre of Integrated Mountain Development (ICIMOD) in Kathmandu, five out of six critical landslides that blocked rivers since the earthquake are located in Nepal. Hundreds of people died from a landslide in Langtang, which was triggered by the quake. Landslides will easily cause disastrous impacts in local mountain communities who have already suffered from the quake.

© DFID
© DFID

The quake also cracked a huge hydroelectric dam and damaged many others. With the monsoon weeks away, there are growing concerns that heavy rainfall will cause the landslides tobecome even more destructive. Coupled with melting glaciers, intense monsoon rainfall is expected to trigger flooding in a country that’s already broken from the aftershocks of the devastating earthquake.

The government has made little progress in mapping landslide-prone areas, said Bishal Nath Upreti, a retired geology professor and chairman of the Disaster Preparedness Network in Nepal, in Malaymail Online. “It’s very hard to convince the government. They didn’t think it was so important,” Upreti said. “It’s urgent to start now.”

© DFAT
© DFAT

“Donating money to Nepal immediately after the crisis is the easy part”, Tsechu Dolma, a GlacierHub writer, emphasized in a post recently published on NBC News. More importantly, local governments should concentrate on reaching rural families who need fast support, and building long-term strategy for Nepal.

Dolma proposed a three-phase plan to build resilience in Nepal. In the early phase, she strongly recommended channeling funds to trustworthy local organizations, which are capable of providing direct relief in mountain communities. In the middle phase, she believes that reconstructing essential infrastructures, including local schools and hospitals, is extremely important. Lastly, attention should be paid towards developing “grassroots community resilience” to increase Nepal’s adaptive capacity to extreme weathers and disasters.

Here are photographs of Nepal after the earthquake, provided by Tsechu. Read more about her article on NBC News.

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Adaptation to Drought in Peruvian Andes

Community-based adaptation strategies are essential for dealing with drought in the Peruvian Andes, according to a new study by Ralph Lasage et al. published in Sustainability.

Extreme Droughts in Quechua (Source: CGIAR Climate/Flickr)
Extreme Drought in  Andean Region (Source: CGIAR Climate/Flickr)

Over 80% of residents in the Peruvian Andes rely on agriculture as a major source of income and are highly dependent on the availability of water resources. But in the past, droughts associated with El Nino events have been devastating for these communities and led to increased migration from rural areas to cities. According to Ralph Lasage and a team of researchers from VU University Amsterdam and Amsterdam University College, the drought of 1982 resulted in 60% – 70% reduction in highland agricultural production.

And water availability in the Andes is set to continue to decline as glaciers recede. Effective water management systems and adaptation measures on the local scale play significant roles in reducing the impacts of climate change on the glaciers thousands of people rely on, Lasage and his team found.

Aguas Calientes (Source: Mariano Mantel/Flickr)
Aguas Calientes, Peru (Source: Mariano Mantel/Flickr)

When glaciers melt, the risk of outburst floods increases dramatically. In 1941, the glacial lake Palcacocha in the Peruvian Andes burst and tons of water crashed into the city of Huaraz, killing around 5,000 people. In the following decade, two more glacial lake outburst floods (GLOFs) occurred in the Cordillera Blanca in north-central Peru due to excessive water released when glacier moraine dams failed. To address the issue, the Peruvian government strengthened terminal moraine dams, sophisticated valve systems, and drain pipes to prevent extensive damage when future GLOFs occurs. In addition, it initiated glaciological unit, which helped prevent many outburst floods and significant fatalities.

Andean Vista (Source: pdh96/Flickr)
Andean Vista (Source: pdh96/Flickr)

However, outburst flooding is not the only glacier melt-related issue that concerns Peruvians. Droughts associated with climate variability, which threaten the country’s water supply, pose a major concern for residents of the South American nation. Shrinking glacier volume during this century is projected to intensify. But hydrological data gaps limit scientists’ ability to understand cycles of flooding and droughts. it is difficult for them to assess vulnerability to floods and droughts on regional level.

Through their study, Lasage and his team presented a stepwise participatory approach to create a vulnerability index and develop community-based adaptation measures. The study was conducted in the Chorunga catchment, which is “representative of the environmental and socio-economic conditions of farming communities across the Andes”. They found that improving the efficiency of water usage and storage was a bigger challenge for communities than creating water storage at high elevations close to glaciers.

Location of the Chorunga study area in the Ocoña River basin. (Source: Ralph Lasage et al., 2015)
Location of the Chorunga study area in the Ocoña River basin. (Source: Ralph Lasage et al., 2015)

The Chorunga catchment, which is part of the Ocona River basin, is a poor rural area where roughly “68% of the population live in poverty, compared with 14% for the whole of Peru”. Located in the south of the Cordillera Blanca, the Chorunga catchment received the majority of its water irrigation comes from the Coropuna Glacier, which lost 37% of its total volume and has been rapidly retreating, in the form of melting glacier water. In addition, the team conducted in-depth study of the functioning of the villages’ irrigation systems and the governance of water resources. Perceived vulnerability was evaluated alongside a variety of socio-economic characteristics of the respondents, including income, education, access to water, and etc.

Quilted Fields, Andes (Source: Rod Waddington/Flickr)
Quilted Fields, Andes (Source: Rod Waddington/Flickr)

Lasage and his team started by gathering information on local households’ perception of their vulnerability to droughts and the effectiveness of proposed adaptation strategies through questionnaires and face-to-face interview in the Chorunga catchment. The vulnerability index was defined as the product of “exposure” (or frequency of drought periods) and “sensitivity” (or perceived impacts of a drought on people’s livelihoods) divided by “response efficacy” (or perceived effectiveness of adaption measures in response to reduced water availability). In addition, the team gathered information on the governance of water resources as well as irrigation systems through in-depth interviews with government offices, NGOs, and local colleges. More importantly, the team collaborated with a variety of Peruvian stakeholders (e.g. local farmers, Water Associations, Irrigation Commissions, and etc.) and initiated several possible adaption measures. Ultimately, some adaption measures were selected on the basis of climate projections and investment costs.

Ocoña River meets Pacific Ocean (Source: beyondhue/Flickr)
Ocoña River meets Pacific Ocean (Source: beyondhue/Flickr)

Glacier recession has been accelerating since the 1970s, which will likely lead to the disappearance of the glaciers. As a result of rising temperatures, a large portion of the precipitation comes in the form of rainfall instead of snow. Therefore, water availability is anticipated to decline during growing season for crops on the long run even though increased melting glacier water will slightly contribute to water runoff in the short term. In other words, additional melt-water from glacier retreat will not make a difference in increasing discharge, because the effect of reduced precipitation due to high temperatures will most likely be overwhelming.

La Raya Pass (Source: David Stanley/Flickr)
La Raya Pass, Peru (Source: David Stanley/Flickr)

The vulnerability analysis reveals that households with a larger area of irrigated land tends to be less vulnerable to droughts; households with lower income are more vulnerable but less willing to adapt to climate change; and people with a higher education appear to be less sensitive to drought and willing to cope with adaptation measures. There is a strong correlation between households’ water availability and their vulnerability to droughts.

Cayetano Huanca, Peru (Source: Oxfam International/Flickr)
Cayetano Huanca, Peru (Source: Oxfam International/Flickr)

The selected adaptation measures concentrated on improving the efficacy of water usage and storage in the Chorunga catchment. In particular, surface dams were constructed to store rainfall during the wet season, and to be used during the dry season. Low-cost gravity drip irrigation systems and water-efficient crops were introduced to maximize crop production in the fields with limited amount of water. In addition, roof-water harvesting systems were installed to increase useable water. Generally speaking, the implementation of such adaptation measures will possibly increase households’ water availability during the dry season, and hence reduce their vulnerability to droughts.

“The stepwise approach proved to be suitable to structure the process of developing and implementing adaptation measures jointly with a wide range of stakeholders in a rural area in Peru. It enabled the inclusion of information ranging from the local to the global scale and led to the joint implementation of several community-based measures”, said Lasage et al.

Glacial Outburst Floods in Greenland Discharge Mercury

Zackenberg Research Station. Source: Aarhus University, Department of Bioscience

Mercury contamination has long been a threat to animal carnivores and human residents in the Arctic. Mercury exports from river basins to the ocean form a significant component of the Arctic mercury cycle, and are consequently of importance in understanding and addressing this contamination.  Jens Søndergaard of the Arctic Research Centre of Aarhus University, Denmark and his colleagues have been conducting research on this topic in  Greenland for a number of years. They published results of their work in the journal Science of the Total Environment in February 2015. Søndergaard and his colleagues assessed the mercury concentrations in and exports from the Zackenberg River Basin in northeast Greenland for the period 2009 – 2013. This basin is about 514 square kilometers in area, of which 106 square kilometers are covered by glaciers. Glacial outburst floods have been regularly observed in Zackenberg River since 1996. This study hypothesized that the frequency, magnitude, and timing of the glacial outburst floods and associated meteorological conditions would significantly influence the riverine mercury budget. Indeed, they found significant variation from year to year, reflecting weather and floods. The total annual mercury release varied from 0.71 kg to over 1.57 kg. These are significant amounts of such a highly toxic substance.

Stream in Zackenberg drainage. Source: Mikkel Tamstrof
Stream in Zackenberg drainage. Source: Mikkel Tamstrof

Søndergaard and his colleagues found that sediment-bound mercury contributed more to total releases than  mercury that was dissolved in the river. Initial snowmelt, sudden erosion events, and  glacial lake outburst floods all influenced daily riverine mercury exports from Zackenberg River Basin during the summer, the major period of river flow. The glacial lake outburst floods were responsible for about 31 percent of the total annual riverine mercury release. Summer temperatures and the amount of snowfall from the previous winter also played important roles in affecting the annual levels of mercury release. The authors note that releases are likely to increase, because global warming is contributing to greater levels of permafrost thawing in the region; this process, in turn, destabilizes river banks, allowing mercury contained in them to be discharged into rivers.

Greenland Seal. Source: Greenland Travel/Flickr
Greenland Seal. Source: Greenland Travel/Flickr

Mercury produces adverse health effects even at low levels. It is commonly known that mercury is toxic to the nervous system. According to the U.S. Environmental Protection Agency (EPA), consuming mercury-contaminated fish accounts for the primary route of exposure for most human populations. Mercury can also threaten the health of the seabirds and marine mammals which consume fish—and which Greenlandic populations. The release of riverine mercury in Zackenberg might not have strong influence in this remote region of northeast Greenland, far from human settlements and with few fisheries to date. However, the total yearly released mercury from all the river basins in Greenland is more significant, and is growing. There is a significant risk of transport in marine ecosystems through food chains, causing mercury poisoning among humans and wildlife in Greenland and in adjacent coastal countries.

Glacier Hazards Linked to Prolonged PTSD in Kids

In June 2013, several days of torrential rains bombarded India’s northern state of Uttarakhand causing devastating glacier lake outburst floods (GLOFs), river flooding, and landslides. This event is considered to be the country’s worst natural disaster since the 2004 tsunami. Packed with Hindu pilgrimage sites, temples, and tourists, Uttarakhand saw entire settlements washed away. Roads were heavily damaged, stranding over 70,000 people and causing food shortages. Local rivers were flooded with dead bodies for more than a week, contaminating water supplies for the survivors.

Based on post-disaster studies, researchers from St. John’s Medical College in Bengaluru, India recently published findings indicating that the Uttarakhand flooding may have provoked sustained levels of post-traumatic stress disorder (PTSD) in adolescents in the region. The study, which was conducted three months after the disaster, found a 32 percent prevalence of PTSD and a wide-range of stress levels amongst the youth of one the hardest hit districts, Uttarkashi.

Torrential rain caused unimaginable flooding in Uttarakhand. Many traditional sites and statues were ruined. (Photo: Flickr)
Torrential rain caused unimaginable flooding in Uttarakhand. Many traditional sites and statues were ruined. (Photo: Flickr)

In order to secure these findings, the research team obtained consent from 268 adolescents at a high school in Uttarkashi. They assessed the mental health of the students by administering the Trauma Screening Questionnaire, an PTSD assessment recognized in the U.S., the U.K., and elsewhere. Another structured questionnaire was used to gather demographic information. The average age of children who participated in the study was 14.8, with slightly more male respondents than female.

Because of a lack of mental health care infrastructure in Uttarkashi, researchers were not able to prove the glacier-related event directly caused the high rates of PTSD amongst the students in this region. However, a similar study of 411 high school students, conducted prior to 2012 in Pune, India found a lower rate of PTSD (8.9 percent for girls, 10.5 for boys). These students had not suffered from a recent natural disaster related event. A meta-study of 72 peer-reviewed articles of US children and adolescents exposed to trauma found an overall rate of PTSD of nearly 16 percent..

A study of 533 tsunami victims in South India found a much higher rate of PTSD, roughly 70.7 percent for acute PTSD and almost 11 percent for delayed onset PTSD. Although there are many factors that may be able to explain the difference in rates, the increased prevalence of PTSD in the Uttarakashi youth certainly signals a link between glacial hazards and PTSD in children.

The loss of a stable lifestyle is a well-known risk factor for PTSD because of an increased feeling of vulnerability to harm. In Uttarakhand, many adolescents experienced this first-hand when their houses were washed away in the floods. (Photo: EU Humanitarian Aid and Civil Protection/Flickr)
The loss of a stable lifestyle is a well-known risk factor for PTSD because of an increased feeling of vulnerability to harm. In Uttarakhand, many adolescents experienced this first-hand when their houses were washed away in the floods. (Photo: EU Humanitarian Aid and Civil Protection/Flickr)

The researchers from St. John’s Medical College note that past research has been able to establish the relationship in adult subjects between natural disasters and PTSD, “the most prevalent psychological disorder after disaster.” Thus, they claim there is a need for greater recognition of post-disaster stress disorder assessment and for interventions among adolescent victims in developing countries.

“The majority of disaster studies have focused on adults, although adolescents seem to be more vulnerable to psychological impairment after disaster which manifests in a variety of complex psychological and behavioral manifestations,” wrote the authors of the study.

The exact cause of the 2013 Uttarakashi district flooding is contested; however, the unyielding rains contributed to heavy melting of the Chorabari Glacier, 3,800 meters above sea level, and this was a significant catalyst in the event. During the week of June 20, melting at Chorabari, due to above average rainfall, led to the formation of a temporary glacial lake. Further torrential rains caused this lake to swell and overflow, inducing flash flooding and disastrous landslides and mudslides. “Eyewitnesses describe how a sudden gush of water engulfed the centuries-old Kardarnath temple, and washed away everything in its vicinity in a matter of minutes,” according to Down To Earth Magazine.

Glacier-related PTSD risk is not unique to the Gangotri glacier region. There is also evidence and historical precedence to connect these environmental and psychological factors in the Hindu Kush region, the Cordillera Blanca area of Peru, and other high mountain ranges with large glacier dimensions because of their increased risk of glacial hazards. Further, as researchers begin to examine the link between climate change related disasters and the well being of communities, they are finding the increase in disasters will likely instigate greater rates of stress, anxiety, depression, and physical illness along with PTSD in exposed populations. The recognition of the impacts of disasters on mental health is an important complement to earlier work, which has focused almost exclusively on property damage and mortality.

Bhutan’s Fortresses Yet Another Victim of Glacial Floods

Dzongs are the most dramatic element of traditional Bhutanese architecture. This particular fortress is located in Lobesa. (photo: Ben Orlove)
Dzongs are the most dramatic element of traditional Bhutanese architecture. The Punakha Dzong is the administrative center of one of the 20 districts of the country. (photo: Ben Orlove)

Two 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.

An image of Tsomem, showing her snake-like hair.   (photo: Ben Orlove)
An image of Tsomem, showing her snake-like hair. (photo: Ben Orlove)

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.

To keep her happy, local people bring offerings, including money and butter-lamps that are common throughout temples in Bhutan, and a special gift only for her, round river rocks. These rocks remind her of her river home, and keep her happy. (photo: Ben Orlove)
Two bills and a round river rock: offerings to Tsomem, a mermaid-like spirit. (photo: Ben Orlove)

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.) The butter lamp burning in front of the shrine was a familiar sight, but I was puzzled by the rocks that I saw near the shrine, quite different from other offerings that I had seen.

 

Two nuns from Lobesa in courtyard of the Punakha dzong. (photo: Ben Orlove)
Two nuns from Lobesa in courtyard of the Punakha dzong. (photo: Ben Orlove)

I continued on to the southern courtyards, and found one spot which, I thought, might still show some damage from the 1994 GLOF. I asked a monk standing nearby about it, but he spoke no English. To my surprise, two nuns who were within earshot replied to my question. They did not know about the possible damage. It turned out that they, like me, had arrived from Lobesa that morning, on a kind of pilgrimage. They asked me if I would like to join them in their visit to the inner watchtower, an invitation which I gladly accepted. We clambered up a set of steep ladders, where on each floor the monk in charge unlocked the door to a temple. He let us in and waited while the nuns made a series of prostrations. He accepted the offerings which they and I placed on the altars, and then poured some water into our cupped hands as a kind of blessing. In the third temple, one of the nuns touched her forehead to an image in a mural with a graceful gesture that suggested to me both reverence and familiarity. When their circuit of the temples was complete, the nuns left to return to their convent in Lobesa, and I strolled around the dzong for another hour. Unready to leave this extraordinary structure, I found a spot to sit with a view of the Bodhi tree, and watched the different kinds of people passing through—monks, local people attending the meeting of county representatives, and foreign tourists with guides.

Punakha dzong shrine to Tsomem, with butter-lamp in front and rock offerings to the side. (photo: Ben Orlove)
Punakha dzong shrine to Tsomem, with butter-lamp in front and rock offerings to the side. (photo: Ben Orlove)

Sangay, the taxi driver who drove me back to Lobesa, remembered the flood when I asked him about it. He had been a boy at the time. Like the others I spoke with, he mimicked its eerie sound, a low “oo” somewhere between a moan and a roar. It awakened him and his family, and frightened them into stumbling up the hillside behind their house. He added a detail that nobody else mentioned: the unpleasant smell of mud that arrived with the flood and lingered for days. He told me that the flood waters were filled with fish that were easy to catch. Pointing to his eyes and his ears, he explained that the turbidity of the waters prevented the fish from seeing, and the sediments clogged their gills so they came close to the surface, where he could easily catch them. Older people told him and his friends that the fish were poisonous, but they ate them anyway.

A carved head on pillar in the Punakha dzong. (photo: Ben Orlove)
A carved head on pillar in the Punakha dzong. (photo: Ben Orlove)

I asked him about the image in the shrine that I had photographed, which he recalled it right away, once I described its location in the courtyard. The being is a female local deity, rather than one of the larger figures in the pantheon who are revered in many sites. Her name is Tsomem, a combination of the word tso, a body of water, and mem, person. She is a Himalayan mermaid, with the upper body of a woman and the lower body of a fish. Though she is usually happy and stays in the river, she can on occasion become unhappy. At these times, she may leave the river and become destructive. To keep her happy, local people bring offerings, including money and butter-lamps that are common throughout temples in Bhutan, and a special gift only for her, round river rocks. These rocks remind her of her river home, and keep her happy.

Though two decades have passed since the flood, it remains fresh in the memory of people in Bhutan. A brief and striking video, “Tsomem’s perspective of Punakha Dzong,” shows the concreteness with which it is recalled. Government agencies monitor glacier-fed lakes to evaluate the changing risk of GLOFs. It seems only a matter of time until the next flood rushes down a valley, threatening lives and structures, whether historic dzongs or the new monuments of Bhutan: the hydropower dams like the one currently being built downstream of the Punakha dzong below Lobesa.

GlacierHub has recently featured posts on my visits to cities and forests in Bhutan.

 

As Glaciers Melt, They Hum Too

Researchers discovered a humming sound coming from the Gorner Glacier next to Gornersee (the tiny lake in blue) in Switzerland. (silent7seven/Flickr)
Researchers discovered a humming sound coming from the Gorner Glacier next to Gornersee (the tiny lake in blue) in Switzerland. (silent7seven/Flickr)

The hills are alive with the sound of… humming? Scientists from the U.S., France and Switzerland recently found that as glaciers melt, they make a low humming sound as water passes through them, according to a new study appearing last month in the journal Geology.

The phenomenon was first observed in the Swiss Alps when a research team placed seismometers near a glacial lake dammed by the Gorner Glacier on the side of the Monte Rosa Massif in an effort to monitor signs of glacier lake outburst floods (GLOFs). As the water from the lake drained through the glacier, the seismometers picked up tiny “harmonic tremors” in the mountain glacier, as well as similar humming sounds made by icequakes near the glacier’s base.

Sliding Fourier transforms (SFT) of 2007 data at the station nearest lake Gornersee, Switzerland (double triangle in Fig. 1), reveal gliding harmonic tremor during a 15 h period on 13 July 2007. The sudden step changes in harmonic tremor frequencies are indicative of hydrofracturing at englacial water-fi lled fractures. A: SFT of data collected from 12 July to 15 July 2007 (7/12–7/15). B: Enlargement of the 13 July record reveals tremor signal in detail. (source: David S. Heeszal, et al./Geology)
Sliding Fourier transforms (SFT) of 2007 data at the station nearest lake Gornersee, Switzerland (double triangle in Fig. 1), reveal gliding harmonic tremor during a 15 h period on 13 July 2007. The sudden step changes in harmonic tremor frequencies are indicative of hydrofracturing at englacial water-filled fractures. (source: David S. Heeszal, et al./Geology)

Part of the reason for the humming is that glaciers aren’t just big solid blocks of ice. Water moves through glaciers in an ever-evolving and complex series of tiny cracks, crevasses and channels (hydrofractures) within the glaciers themselves. Small pockets of water open and close within glaciers all the time as water flows from one part to another. Though how exactly this englacier water (that is, water within a glacier) moves isn’t yet fully understood.

The seismographs were able to measure the hums as water-filled cracks within the glacier opened and closed, but the humming noises were often at such a low frequency that a human ear could not detect them.

Humming glaciers are more than just a curious scientific phenomenon. The paper’s authors state that further research into the hums at the Gorner Glacier might lead to the development of an early warning system against GLOFs. In other words, glaciers may have a built-in alarm systems. GLOFS are difficult to predict because water draining from the lakes can follow a number of different paths over, under or through a glacier that is acting as a boundary or border for the lake, holding the lake water in place. Just watching the surface of the lake isn’t enough to predict when a massive flood will occur. Fortunately, when glaciers go, they don’t go quietly.

Switzerland's Gorner Glacier as seen from space. (NASA)
Switzerland’s Gorner Glacier as seen from space. (NASA)

As Glaciers Melt, A Lake in Nepal Fills Up

 

Looking south on the way down from Island Peak (6189 m / 20305 ft), also known as Imja Tse, in Nepal Himalaya. Ama Dablam is to the right and Imja Tsho (lake) is down in the middle.(Kiril Rusev/Flickr
Looking south on the way down from Island Peak (6189 m / 20305 ft), also known as Imja Tse, in Nepal Himalaya. Ama Dablam is to the right and Imja Tsho (lake) is down in the middle.(Kiril Rusev/Flickr

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.

The Imja Tsho lake has been filling with glacial meltwater at an alarming rate. Since the 1960s, the lake has increased 2,000 percent. (Matt Westoby/Flickr)
The Imja Tsho lake has been filling with glacial meltwater at an alarming rate. Since the 1960s, the lake has increased 2,000 percent. (Matt Westoby/Flickr)

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.

Villages like this one in the valleys below Imja Tse face a constant risk of glacial lake outburst floods.jarikir/Flickr)
Villages like this one in the valleys below Imja Tse face a constant risk of glacial lake outburst floods.jarikir/Flickr)

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 siphoning or controlled drainage canals.” They emphasized the importance of letting the community decide, as opposed to outside groups or government.

But many residents are simply fed up with all of the warnings and scientific predictions. “We’ve been living in the shadow of this lake for so long now,” Ang Nima Sherpa, a local businessman told the Guardian in 2011. “The only thing I am interested in hearing about now is whether they can get us a hydroelectric plant out of that lake.”

 

Satellite Images Offer Clues to Causes of Glacial Lake Flooding

(from journal article: Field observations for glacial lakes: (a) the rapidly expanding Lake Longbasaba in 2012; (b) an areally increasing glacial lake at the Middle Rongbu Glacier near Mount Qomolangma (Everest) in 2008.)
(from journal article: Field observations for glacial lakes: (a) the rapidly expanding Lake Longbasaba in 2012; (b) an areally increasing glacial lake at the Middle Rongbu Glacier near Mount Qomolangma (Everest) in 2008.)

Satellites are now allowing us to track the behavior of icy glacial lakes on the Himalayan Mountains–in particular the conditions that lead to glacial lake outburst floods (GLOFs), which have become increasingly frequent in the region over the past 20 years.

Researchers from the Institute of Mountain Hazards and Environment and the State Key Laboratory of Cryosphere Sciences in China published a study in PLOS One in December of last year that catalogued data from lakes in the central Himalayas between 1990 to 2010.

The scientists, Drs. Yong Nie, Qiao Liu, and Shiyin Liu, used images from Landsat scientific satellites to count and measure glacial lakes in the region. As the longest running remote sensing project, Landsat has over 40 years of images available across the globe.

(from journal article: Distribution of glacial lakes in the central Himalayas)
(from journal article: Distribution of glacial lakes in the central Himalayas)

GLOFs – floods that occur when a lake dammed by a glacier or glacial moraine is released – are hazardous to communities located at elevations below the burst lake. Flooding and debris flows damage infrastructure, cause property loss, and can take lives, as GlacierHub has reported in prior posts. It is widely believed that rising temperatures due to climate change and reduced albedo of the ice from cryoconite (also known as carbon dust particles) are melting the glaciers at higher rates and causing lake volumes to rise, which in turn increases the risk of GLOF events. But the specific processes that lead to GLOF outbursts are not well understood.

By looking at lakes at four time points (1990, 2000, 2005 and 2010), at different elevations (from 3,500 to 6,100 meters), of different types (pro-glacial and supraglacial), and of varying sizes, the researchers were able to identify which lakes expanded faster and burst more frequently to understand which ones pose the greatest risk of GLOFs.

A GLOF from above in Alaska’s Kennai Peninsula (Travis S./Flickr, some rights reserved)
A GLOF from above in Alaska’s Kennai Peninsula (Travis S./Flickr, some rights reserved)

Overall, it was found that total lake surface area for the 1,314 lakes in the central Himalayas had increased over the 20-year period. Drs. Nie, Liu and Liu found that more lakes on the northern side of the central Himalayan range were expanding rapidly. They also found that pro-glacial lakes (lakes at the terminus of a glacier) grew faster than supraglacial lakes (lakes on the surface of the glacier). Some pro-glacial lakes are connected directly to glaciers while others are not, but those that were connected grew far faster. Additionally, larger pro-glacial lakes were likely to flood sooner than smaller ones and more changes to glacial lakes occurred at the altitudes between 4,500 and 5,600 meters.

The dynamics of alpine glacial lakes are complex, but this study could help communities monitor lakes at high risk of flooding and to create early-warning systems and disaster preparedness plans.

PAPER DOI: 10.1371/journal.pone.0083973.g002

GLOF aftermath in Peru ( Will McElwain/Flickr, some rights reserved)
GLOF aftermath in Peru (Will McElwain/Flickr, some rights reserved)

Flooded with memories in Nepal

Trail in Pharak. (Pasang Sherpa)
Trail in Pharak. (Pasang Sherpa)

I 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.

Rock painting in Khumbu. (Pasang Sherpa)
Rock painting in Khumbu. (Pasang Sherpa)

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.

Rock painting in Pharek. (Pasang Sherpa)
Rock painting in Pharek. (Pasang Sherpa)

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.

Planting potatoes. (Pasang Sherpa)
Planting potatoes. (Pasang Sherpa)

Nowadays, many people in the Sherpa region talk about the potential Imja GLOF. We have heard about the expanding Imja Tsho and the destruction it could cause to our villages. Most of this information comes to our villages from the media, the scientists and NGO sponsored projects that organize workshops there. When there is heavy monsoon rain, my maternal grandmother and her children, my uncles and aunts, worry about the rising water levels in the river. They live in Thumbuk, a village below Monzo, which is close to the river. The discussions about Imja Tsho flooding that have now spread throughout the villages leave the villagers more with a sense of dread than with a feeling of preparation.

Several years ago, my uncle and his wife found themselves running for their lives along with other villagers after they received a phone call from their friends in a different village that told them the Imja Tsho was flooding. This was later found to be a rumor spread by some people from Khumbu, a much higher Sherpa area close to the Imja Tsho. They were alarmed by a recent information-sharing workshop that discussed the potential Imja GLOF and showed its likely path of destruction, including several middle-elevation Pharak villages that would be directly affected. Among the people who fled was a young mother with her newborn child. They found refuge in their wet potato field on that cold, rainy night. The great discomfort that they experienced brought to mind my grandparents’ concern that talking about misfortune was nomdok. Even well-intentioned discussions can create misunderstanding, confusion and fear, and lead to harm that might otherwise be avoided.

This guest post was written by anthropologist Pasang Yangjee Sherpa of Penn State.  If you’d like to write a guest post for GlacierHub, contact us at glacierhub@gmail.com or @glacierhub on Twitter.