The rapid retreat of the world’s land ice means that glacial lakes — bodies of water formed by glacial meltwater — risk collapsing in potentially unexpected and catastrophic floods that threaten downstream communities.
University researchers in the United Kingdom and the United States have, for the first time, modeled the potential risk for glacial lake outburst floods, or GLOFs, for three lakes in the Bolivian Andes. Their results, published in December in the journal Natural Hazards, show that as many as 2,200 people could be impacted by flooding in six communities located downstream from each of the lakes. And, the researchers found, up to 2,100 people could be exposed to flooding of 2 meters or more, which “could be life threatening and cause a significant damage to infrastructure.”
The researchers focused on Pelechuco, Laguna Glaciar, and Laguna Arkhata, which are located within the Cordellera Oriental, Bolivia’s major mountain system.
Simon Cook of the University of Dundee in the United Kingdom and one of the authors of the study told GlacierHub that the researchers chose the lakes because a previous study they developed a technique for assessing GLOF risk.
“Using a carefully chosen set of criteria, we narrowed down 25 lakes that had been previously recognized to have the capacity to generate a damaging GLOF to three that were estimated to have ‘medium’ or ‘high’ GLOF risk,” he said. “These all have slightly different characteristics, but fundamentally they all sit up-stream from human settlements and are situated very close to either steep valley slopes or hanging glaciers that could shed debris or ice into the lakes, thereby generating an overtopping wave.”
The communities were Agua Blanca and Pelechuco, which are located downstream from Pelechuco, Sorata, which is downstream of Laguna Glaciar, and Totoral Pampa, Tres Rios, and Khanuma, which are located downstream from Laguna Arkhata.
The authors modeled water flows that might result from varying GLOF events. “This modeling approach has already been used to model GLOFs from Lake 513 in Peru and in Chilean Patagonia, as well as in other regions of the world,” Cook said.
To test the accuracy of their model, the researchers ran simulations of a 2009 GLOF that occurred in Keara, located in the Apolobamba region of Bolivia. The model proved to “reproduce realistic flood depths and inundations.”
The researchers modeled three GLOF scenarios that projected “optimistic,” “intermediate,” and “pessimistic” levels of drainage flows. They were then able to estimate the number of buildings and people that might be affected by a flood.
They found, in total, between 1,140 and 2,202 people could be affected if all of the lakes were to burst, and between 843 and 2,119 people could be exposed to flow depth of at least 2 meters. Between 510 and 979 buildings could be affected if all of the lakes were to burst, according to the researchers’ model.
Ioannis Kougkoulos of the University Nottingham in the United Kingdom and lead author of the study told GlacierHub in an email that economic or infrastructure concerns among residents often trump the risk of flooding. “So they cannot put all the focus on these low-frequency natural disasters,” he said.
Laguna Arkhata and Pelechuco lake, according to the authors, represent the greatest GLOF risk due to the large numbers of people who live in the potential flow paths.
To address these risks, the authors suggest cost-benefit analyses that consider community relocation, community awareness programs, and early-warning systems.
Greenland and Iceland have been periodically reshaped by megafloods over thousands of years, a new paper in the journal Earth-Science Reviews has revealed.
British research duo Jonathan Carrivick
and Fiona Tweed have
provided the first evidence of gargantuan Greenlandic floods and extensively
reviewed the record of comparable events in Iceland. The researchers set out to
better understand what constituted a megaflood and find traces of them recorded
in the landscapes of these icy islands.
In media stories and even within the scientific literature the authors found that terms like “catastrophic flood,” “cataclysmic flood,” and “super flood” have been used indiscriminately and interchangeably. There are, however, strict definitions associated with each. A “catastrophic flood,” for instance, occurs when peak discharge exceeds 100,000 cubic meters per second — more than 18 times greater than the flow over Niagara Falls. Multiply that by ten (i.e. 1,000,000 cubic meters per second) and you get a sense of what constitutes a true megaflood.
Despite expressly seeking records of megafloods in the landscape
and literature, Carrivick and Tweed found that a more practical approach was to
identify events with “megaflood
attributes.” Scientists have recorded very few true megafloods since
those that cascaded off the Laurentide Ice Sheet, which
once mantled much of North America in the aftermath of the Last Glacial Maximum. While
there have been few recent floods that exceed one million cubic meters per
second, there have been several with comparable erosive power and lasting
Shaped by water
In Greenland, Carrivick and Tweed found 14 sites where huge floods had rampaged down fjords and across expansive “sandur,” or outwash plains. These have typically been outbursts from ice-dammed lakes, which have periodically unleashed inconceivably vast volumes. The glacial lake Iluliallup Tasersua empties every five to seven years and has a capacity of more than six cubic kilometers of water. At its peak, that flow would drown New York City’s Central Park in a column of water deeper than four Empire States Buildings.
Iceland, too, has experienced
its fair share of monstrous floods. Many of them have were triggered by
volcanic eruptions. Due to the unique setting of Iceland, where the active
fire-breathing mountains of the Mid-Atlantic island are blanketed with ice caps
and glaciers, erupting magma invariably explodes into the underside of a
quenching ice mass. This interaction, more often than not, results in an outburst
flood known locally as a “jökulhlaup,”
which produces tremendous amounts of power that is capable of reshaping and
inundating the island’s plains.
The region surrounding Öræfajökull, one of the most active
volcanoes in Iceland, is infamous for having suffered from devastation wrought
by both fire and ice.
“After it erupted in 1362, the
whole area was renamed as ‘Öræfi,’ which means ‘The Wasteland,” Tweed told
GlacierHub. “They renamed the area because it had been inundated by a grey
sludge, hyper-concentrated flow deposits and volcanic ash which had eradicated
the farmland and rendered it unusable.”
The eruption was the largest in Europe since Vesuvius immortalised
the communities of Pompeii and Herculaneum in AD79. The floodwaters rushed out
at over 100,000 cubic meters per second — qualifying as a “catastrophic flood.” The torrent was
so powerful that it was able to transport rocks weighing 500 metric tons, each
equivalent to four and a half blue whales. Despite not strictly meeting the
definition of a megaflood, the event certainly bore many of the hallmarks of
But the impacts of such deluges are not limited to their power to remold centuries-old landforms, toss about house-sized chunks of ice, or transport a beach-worth of sediment in a matter of hours.
Outbursts in Greenland can release as much as six billion metric tons of water within a matter of 7-10 days. This rapid draining of a glacier-lake basin radically changes the pressure atop the ice sheets, causing isostatic rebound, which can result in fractured shorelines, as localized sections of coast re-expand.
Water from an outburst flood often passes through a highly pressurized network of conduits within, beneath, and alongside ice. This can trigger a “seismic tremor.” So-called “glacier-derived seismicity” has been measured via seismometers since the early 2000s and experienced by eye-witnesses in the vicinity of Grænalón, one of the most famous jökulhlaup systems in Iceland. The authors note that while these events can be detected and felt, there is negligible impact from them.
Consequences for communities and corporations
Glacier floods also impact the communities living in the shadow of ice. Carrivick and Tweed’s previous work revealed that Iceland has experienced at least 270 glacier outburst floods across 32 sites, killing at least seven people. This makes Iceland among “the most susceptible regions to glacier floods” — and the economic costs that often result.
Icelanders are well acquainted with the natural dangers. Volcanic
eruptions, floods, and other geohazards are signature characteristics of their
Looking to the future, Tweed said: “We can expect to have jökulhlaups for another 200 years, until the ice
Such dire flood predictions are unlikely to rattle the stoic
Icelanders, who are more liable to fear the prospect of an Iceland bereft of
In even less populous Greenland, with people rarely situating
themselves in known flood paths, the impacts appear to be less disastrous. That
said, Carrivick noted: “When these big
outburst floods go into the fjords, and move out of the fjords and up and down
the coasts, you get these visible sediment plumes.”
The influx of sediment and freshwater changes the temperature,
salinity, and turbidity of the water in a fjord and the nearby ocean, which can
drive fish out the region. “It
basically shuts down the fishing industry for a couple of days at least,” Carrivick
Yet longstanding industries are not the only ones exposed to
the fickleness of Greenland’s glacier outbursts. As the ice sheet melts, a
number of resources are being eyed by extractive industries. Carrivick
recounted meeting teams of Swiss experts who had been commissioned by
Australian mining companies to set up rigs and conduct mineralogical
investigations in deglaciating regions.
He also remarked on the prospects of the hydropower industry, which has taken advantage of booms in other nations, like Nepal. “It might be an exaggeration, but I think it’s goldrush time,” he said. Regulators, he added, might struggle to keep up with monitoring and mitigating environmental impacts.
Whatever the future holds for Iceland and Greenland, Carrivick and Tweed’s research advances significantly scientific knowledge of the history of flooding on these two islands and makes a strong case for remaining attentive to the changes occurring on their diminishing ice masses.
A Glacier State Congressman Cites Climate Change as Basis for Nuclear Energy Legislation
Senator John Barrasso, a Republican representing the glacier state of Wyoming, is chairman of the Senate Committee on Environment and Public Works. On April 24, Barrasso released a draft act reforming U.S. nuclear waste policy, to ensure the federal government’s legal obligations to dispose of spent nuclear fuel and high-level waste are fulfilled. His reason? Climate change.
“When John Barrasso, a Republican from oil and uranium-rich Wyoming who has spent years blocking climate change legislation, introduced a bill this year to promote nuclear energy, he added a twist: a desire to tackle global warming.
Mr. Barrasso’s remarks
— “If we are serious about climate change, we must be serious about
expanding our use of nuclear energy” — were hardly a clarion call to
action. Still they were highly unusual for the lawmaker who, despite
decades of support for nuclear power and other policies that would
reduce planet-warming emissions, has until recently avoided talking
about them in the context of climate change.
The comments represent an important shift among Republicans in Congress. Driven by polls showing that voters in both parties — particularly younger Americans — are increasingly concerned about a warming planet, and prodded by the new Democratic majority in the House shining a spotlight on the issue, a growing number of Republicans are now openly discussing climate change and proposing what they call conservative solutions.”
Major UN Meeting Raises Minority Rights Issues in Asia’s Glaciated Mountain Areas
The United Nation’s Permanent Forum on Indigenous Issues held its annual meeting in New York City April 22 – May 3. There was significant debate about China’s treatment of minority peoples in the glaciated western provinces, Tibet and Xinjiang. The UN Press reports:
“Despite scattered gains in land, language and legal rights, a glaring lack of political will around the world is inhibiting fundamental change on the ground in thousands of communities in every region, delegates told the Permanent Forum on Indigenous Issues today as it continued its work.
Achievements outlined by Member State representatives today were
starkly overshadowed by grave concerns – including high youth suicide
rates, social exclusion and widespread political apathy – raised by many
speakers, as the Permanent Forum concluded its general discussion on
“implementation of the six mandated areas of the Permanent Forum with
reference to the United Nations Declaration on the Rights of Indigenous
Peoples”. The six areas are economic and social development, culture,
the environment, education, health and human rights.
Across these areas – from land marred by war or extractive industries’ activities to ignorance about indigenous history and languages – speakers called on Governments and the Permanent Forum alike to urgently take the kind of actions that will have a direct, positive impact on their communities.”
An Early Warning System for Peru’s GLOF-Prone Lake Palcacocha
In northwestern Peru, government officials announced plans to install an early warning system to alert downstream populations of glacial lake outburst floods (GLOF) from the Andean glacier lake, Palcacocha,
The lake has a history of GLOFs . Most recently, an avalanche from a calving glacier above the lake on February 5 triggered a wave that tested the moraine holding back the glacial meltwater. The regional capital, Huaraz, which lies downstream, is the second most populous city of the Peruvian Andes.
Peruvian news outlet El Comercio reported on the new warning system, which is expected to take one year to complete.
Glacial lake outburst floods, GLOFs for short, are expected to increase in frequency over time as global temperatures warm. These floods can be very sudden, fast-flowing, and powerful enough to form their own seismic signatures. They carry water, rocks, trees, and debris down valleys, destroying homes and sometimes killing people and livestock.
Many glaciers such as ones in the Hindu-Kush, Karakoram, and Himalayas are shrinking rapidly, forming glacial lakes and causing potentially catastrophic floods for tourists and nearby communities. Understanding the influence of climate change on the frequency and intensity of GLOFs will help disaster risk managers in developing early warning systems and disaster response plans.
Although experts expect these moraine-dammed glacial lakes to grow in size with the addition of glacial meltwater, the risk of GLOFs doesn’t necessarily increase everywhere. In a recent article published in Nature Climate Change, Georg Veh and several of his colleagues from the University of Potsdam and the GFZ German Research Centre for Geosciences examined historical flood occurrences in the the Himalayas that were considered to be hotspot regions for glacier retreat. They aimed to observe GLOF activity for the last few decades, assessing changes in frequency and trend.
Some climate scientists hypothesize that dangerous GLOFs will become more frequent with the growth of moraine-dammed glacial lakes. According to Veh and his colleagues, testing this hypothesis is confounded by incomplete data. Historical reports on GLOF activity are selective, and the researchers speculated that 40 reports on GLOFs in the Hindu-Kush, Karakoram, and Himalayas since 1935 only accounted for large and destructive cases. This suggests that a significant portion of the data might be missing.
To account for reporting bias, the team examined changes in GLOF frequency through a systematic inventory of activity in the Hindu-Kush, Karakoram, and the Himalayas. They were able to identify moraine-dammed lakes and activity in Landsat images from the late 1980s to 2017. Researchers used a random forest model, which was able to generate land-cover maps. These maps provided probabilities for water, cloud, shadow, ice, and land cover across the image tiles. During GLOFs, lakes would abruptly decrease in size, changing from a water to land classification in the Landsat image.
The research team mined over 8,000 Landsat images of the region. In addition to the 17 GLOFs reported since the 1980s, the researchers added 22 newly detected occurrences. They found that despite increasing rates of meltwater entering glacial lakes, particularly in the central and eastern Himalayas, which observed rates of up to six times higher than the northern basin, GLOF abundance remained low.
The average annual rate of 1.3 GLOFs in the region remained unchanged over the last three decades. The fraction of GLOFs per unit of meltwater area, however, has declined since the 1990s.
“We infer that climate-driven rates of glacier melt and lake expansion may be unsuitable predictors of contemporary outburst potential,” stated the researchers.
Their findings were consistent with research on glacial lakes in the Patagonian Andes.
The scientists inferred that their result may indicate a sort of resilience to climate-driven triggers such as glacier calving and ice avalanches, the most frequently reported cause of GLOFs. Unfortunately the team was unable to identify triggers for the 22 newly identified outburst floods, although 16 of them came from pro-glacial lakes within proximity of their parent glaciers. GLOFs generated by calving and avalanche events become less relevant as glaciers retreat from the lakes they have formed.
They also mentioned the importance in perceiving the role of alternate triggers such as earthquakes and landslides in the formation of outburst floods. They give the example of the 2015 Gorkha earthquake in the Nepalese Himalayas. The 7.8 magnitude earthquake did not provoke GLOFs, but it generated landslides which hit glacial lakes.
Veh said the research demonstrated that climate as a sole driver did not change GLOF frequency over the last decade, but that does not mean that frequency will remain unchanged in the future.
“Reliably projecting the future frequency of outburst floods remains an open issue, given that our current knowledge of triggers is quite vague today,” Veh said. The updated inventory of outburst floods will allow for further examination of these cases in more detail.
“Better knowledge of the processes involved in glacial lake outburst floods will ultimately reduce current uncertainties in hazard and risk assessment,” he added.
The researchers believe new generations of optical and radar sensors may be effective in better recognizing GLOF triggers and determining when the next glacier lake outburst flood might occur.
“Glacial lake outburst floods (GLOFs) pose a significant, climate change-related risk to the Mt. Everest region of Nepal. Given the existence of this imminent threat to mountain communities, understanding how people perceive the risk of GLOFs, as well as what factors influence this perception, is crucial for development of local climate change adaptation policies. A recent study, published in Natural Hazards, finds that GLOF risk perception in Nepal is linked to a variety of socioeconomic and cultural factors.”
“Amid the tropical Andes of Peru lies the Cordillera Blanca mountains, home to more tropical glaciers than anywhere else on Earth. This range provides water to some 95 million people. Rising temperatures over the last several decades, however, mean its once abundant glaciers are vanishing rapidly. That’s impacting the water supply of downstream communities, which are becoming increasingly dependent on soil moisture.
In an innovative study published in the journal Remote Sensing of Environment, researchers used drones to obtain high-resolution images of the valleys left behind as Cordillera Blanca’s glaciers recede. As the drones pass over these “proglacial valleys,” they can produce highly accurate maps of the soil moisture within the fields, rivers, wetlands, and meadows below.”
Heavy Snowfall and the Threat of Avalanches in Switzerland
“In January, officials dropped a series of controlled explosives to set off avalanches on mountains near the Moiry Glacier in southern Switzerland due to an increased amount of snowfall during the month. Communities are directed to stay inside (or preferably go into a basement) while the avalanches are triggered and close all shutters. Controlled avalanches are intended to reduce the severity of an avalanche as well as collateral debris from an avalanche, making it safer for adventurers to romp around the backcountry. The use of explosives to mitigate avalanche risk is used throughout many mountain communities, especially when areas experience above average snowfall.”
Glaciers in the Hindu Kush Himalayan (HKH) region are projected to shrink by one-third by the end of the century even if average global temperature rise is held to within 1.5 degrees Celsius above pre-Industrial Age levels, according to the authors of a new comprehensive report, The Hindu Kush Himalaya Assessment.
Glacier melt of that magnitude has widespread implications. Nearly two billion people live within the 10 river basins that make up the HKH region, and food produced there is consumed by 3 billion people.
The report is likely the most comprehensive climate assessment of the area: It includes input from over 300 experts, researchers, and policymakers.
The HKH region, which spans 3.5 million square kilometers, across eight countries, contains two of the world’s highest peaks, Mount Everest and K2.
“This is a climate crisis you have not heard of,” Philippus Wester, a lead author of the report, toldThe New York Times. “Impacts on people in the region, already one of the world’s most fragile and hazard-prone mountain regions, will range from worsened air pollution to an increase in extreme weather events.”
Key Climate Findings
Factors such as climate change, globalization, human conflict, urbanization, and tourism are quickly altering the HKH region, the assessment authors say.
Warming in the HKH region is strongly attributed to anthropogenic greenhouse gases. The authors say that if average, global temperature rise is 1.5°C, the HKH region will see an additional 0.3°C temperature rise.
In other words: The region could warm as much as 1.8°C even under ambitious efforts to limit human-generated greenhouse gas emissions. And the northwestern Himalayas and Karakoram, an expansive mountain range of 207,000 square kilometers that extends from eastern Afghanistan to southern China, could experience at least a 2.2°C temperature rise.
This warming could lead to increased glacial melt, biodiversity loss, and decreased water availability, the authors say. The Tibetan Plateau, which lies south of the Himalayas, will likely face decreased snow cover as temperatures rise. Elevation-dependent warming is a major contributor to the geographic changes in this region.
Other future climate changes include increased frequency of extremely warm days and decreased frequency of extreme cold ones.
The State of the HKH Cryosphere
The Hindu Kush Himalaya cryosphere is comprised of glaciers, snow, ice caps, ice sheets, and permafrost. Future temperature changes will influence the timing and magnitude of meltwater runoff. The report’s authors find that snow-covered areas will decrease and snowline elevations will rise.
Loss of glacial volume in the region will increase runoff and the size of glacial lakes, resulting in a higher potential for Glacier Lake Outburst Floods, or GLOFs, and other hazards. Thawing permafrost is also expected to continue, resulting in the weakening of mountain slopes and peaks.
Messages to Policymakers
“Climate change impacts in the mountains of the HKH are already substantive. Increased climate variability is already affecting water availability, ecosystem services, and agricultural production, and extreme weather is causing flash floods, landslides, and debris flow,”according to the assessment’s authors.
Without immediate mitigation and adaptation policies, they conclude that the region’s glaciers—and therefore Hindu Kush Himalaya residents—face extraordinary threats.
The emergence of the term “climate risk” to describe regions and people negatively impacted by the effects of climate change is now informing adaptation planning in highland areas. A recent study from Environmental Science and Policy reviews a pilot program in the Indian Himalayas that considers climate risk for glacial lake outburst floods (GLOFs) and other weather-related flooding to create an adaptation plan specific to the region. The research finds that a climate risk assessment framework can contribute to sustainable adaptation planning for communities.
The research was a collaborative effort under the Swiss Agency for Development and Cooperation and the government of India’s Indian Himalayas Climate Adaptation Programme (IHCAP), an initiative based on the country’s National Action Plan on Climate Change. IHCAP “aims to enhance the resilience of vulnerable communities in the Indian Himalayas through strengthening the capacities of Indian institutions in climate science, with a specific focus on glaciology and related areas, as well as institutional capacities of Himalayan states in India on adaptation planning, implementation and policy.” With this in mind, a statewide assessment was done of Himachal Pradesh, an Indian state in the Himalayas, followed by a more focused assessment of the Kullu District, one of the state’s identified hot spots for climate risk.
Located in the north-west of Himachal Pradesh, Kullu District is home to over 437,000 people and sits along the valley of the Beas River, with many floodplains running throughout. According to the study, floods are considered a major threat and the potential for GLOFs— events caused by glacier melting and lake expansion— is increasing significantly, with “enhanced risk extending far downstream from where the potentially dangerous lakes originate,” according to the research.
“Adaptation strategies need to be underpinned by robust science,” Simon Allen, one of the study’s researchers from the Institute for Environmental Sciences at the University of Geneva, told GlacierHub. Otherwise, he says, the worst-case scenario is that strategies such as Early Warning Systems could be installed in the wrong locations or may not be adequate for the magnitude of the event expected. This point supported the study’s analysis of climate risk into the categories of hazard, vulnerability, and exposure during the initial scientific assessment. An integrated risk assessment was then undertaken.
Considering components of climate risk combines aspects of disaster risk management and climate adaptation planning to create a comprehensive approach for the management of flood risk. It originates from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change as an integrative approach to managing vulnerability in the face of climate change, and has been since utilized by the C40 Cities network to increase resilience in cities such as Toronto and Amsterdam. It offers a framework for approaching adaptation that emphasizes locating and managing hot-spots of climate risk.
With a solid scientific risk assessment as a foundation, the Kullu District’s adaptation planning was approached with an emphasis on local participation. “The strategies and the underlying science need to be strongly supported by the local stakeholders, and this support and trust takes time to build,” noted Allen. The element of trust is important as it increases the likelihood of a successful project and allows the sharing of vital local knowledge. To build this trust, the locals were involved from the beginning with repeated consultations during the climate risk study and maintained control over the final decisions on adaptation options.
Multiple adaptation plans were discussed during several community workshops and meetings to address both the GLOF and monsoonal flood risks. This allowed the locals to utilize their unique knowledge of the area to determine what would be most beneficial according to their community’s concerns, goals, and institutional capacity. In the study, the support of the district’s disaster management authority was crucial in the political context of the area.
This resulted in the final adaptation proposal involving two components: glacial lake development monitoring and an instrumental monsoon flood early warning system (EWS) in the Parvati Valley, which proved to be a risk hot-spot. EWSs have been used successfully in nearby countries such as Nepal, where their remote data collection system alerted local authorities of rising water levels due to monsoonal rains.
“This strategy recognized that monsoon floods are the very real and frequently observed threat to lives and property in Parvati Valley,” according to the study. It was also able to acknowledge the local interest in preparing for a potential GLOF threat.
The study placed an emphasis on low-regret options when working with local authorities. These options include continued knowledge exchange between the Swiss and Indian partners or incorporating training for local decision-makers to ensure successful flood preparation and response. It aims to strengthen local capacities to deal with flood emergencies, which will bring immediate benefits, but also intends to help in the long-term by dealing with the rapidly evolving and uncertain future GLOF threat, according to Allen. “I don’t see it as a barrier, but rather an additional motivation and opportunity to deal with the very real and existing flood threat from seasonal monsoon rainfalls, while also keeping one eye on the rapidly evolving GLOF threat,” he said.
The pilot study is one of the few to thoroughly and successfully integrate climate risk into the assessment framework of the adaptation planning process. The ultimate goal is to utilize the strategies developed during the project in the Kullu District and upscale them to other areas of the Indian Himalayan region. This expansion will ideally be done with one of the study’s core concepts at the forefront: “While science should closely inform the decision-making process, only those actions that are strongly desired and supported by local stakeholders will prove sustainable in the long-term.”
Emerging from Glacier Permafrost: New Purple Bacteria found in Tianshan
From International Journal of Systematic and Evolutionary Microbiology: “A Gram-stain-negative, motile and rod-shaped bacterium, designated strain B2T, which can synthesize purple pigments of violacein and dexyoviolacein, was isolated from Tianshan glacier in Xinjiang, China…. Based on genomic relatedness, physiological, biochemical and chemotaxonomic data, strain B2T […] is considered to represent a novel species.”
Understanding GLOF Dynamics in Arid Andes of Chile
From Natural Hazards: “We study a remarkable GLOF triggered by the failure of a subglacial lake in the Manflas Valley, Arid Andes of Chile, in 1985 providing insights into the lake’s origin, clarifying the failure mechanism and modeling the GLOF event-related dynamics… We show that the failed lake (4 × 106 m3) formed in a low-slope (≤ 10°) area and that extreme (≥ 90th percentile) annual precipitation before the GLOF contributed to the lake filling and probably to the dam collapse.”
Check out more about what scientists have learned from the 1985 GLOF event here.
Exploring the Factors Behind Flow Rates in Greenland’s Exit Glaciers
From Science: “The largest uncertainty in ice sheet models used to predict future sea-level rise originates from our limited understanding of processes at the ice-bed interface… We find that this sliding relation does not apply to the 140 Greenland glaciers that we analyzed.”
From Geomorphology: “The identification of different ice flow configurations, evidence of subglacial water and past ice margin collapse indicates a dynamic ice sheet margin with varying glacial conditions and retreat modes. We observe that some of the described morphological associations are similar to those found in the Amundsen sea sector of the West Antarctic Ice Sheet (WAIS) where they are associated with ice sheet and ice stream collapse. Although further studies are needed to assess the precise timing and rates of the glacial processes involved, we conclude that there is enough evidence to support the hypothesis that the EAIS margin can behave as dynamically as the WAIS margin, especially during glacial retreat and ice sheet margin collapse.”
Read more about the past behaviors of the East Antarctic ice sheet’s glaciers here.
Environmental Impacts of Mining in Glacier Regions
From the Leibniz Institute for East and Southeast European Studies: “The ugly side of Kumtor is that an open-cast mine in pristine mountain conditions is bound to have negative environmental consequences. Combined with global climate change, the threat to glaciers and to sustainable water supplies downstream is severe. Kumtor’s owners and managers are aware of the issue; the questions are to what extent is the company responsible for countering environmental damage and what is the role of the government in protecting the environment?”
Read more about the Kyrgyz Republic’s gold mine here.
Preparing for Glacier Lake Outburst Floods in India
From Environmental Science and Policy: “Over recent years, at the level of international climate science and policy, there has been a shift in the conceptualization of vulnerability toward emergence of ‘climate risk’ as a central concept. Despite this shift, few studies have operationalized these latest concepts to deliver assessment results at local, national, or regional scales, and clarity is lacking. Drawing from a pilot study conducted in the Indian Himalayas we demonstrate how core components of hazard, vulnerability, and exposure have been integrated to assess flood risk at two different scales, and critically discuss how these results have fed into adaptation planning.”
Read more about translating climate risk in planning for floods in the Indian Himalayas here.
How certain is it that climate change increases the frequency and severity of glacier lake outburst floods or GLOFs? It turns out the answer is complicated and the subject of a new study published in The Cryosphere. Although previous research has examined the nature and characteristics of GLOF events in mountain ranges across the world, this recent study provides the first global assessment of the problems involved in developing a robust attribution argument for climate change and GLOF events.
GlacierHub has covered GLOFs throughout the years including major milestones into understanding their characteristics and an interview with a Peruvian farmer explaining his ongoing lawsuit with a German energy firm over climate risks. However, the GLOFs in this study refer specifically to ones caused by the failure of moraine dams. The formation of these moraine-dammed lakes and resulting GLOFs involve the process of thinning, flow stagnation, and glacier recession. Such moraines often contain a melting ice core built from transported rock debris. And, as stated in the study, “when they fail, large volumes of stored water can be released, producing glacial lake outburst floods.” These floods have already caused hundreds of fatalities across the world, destroying downstream communities and stunting the socio-ecological integrity in their wake.
This study presents an unprecedented global GLOF inventory related to the failure of moraine dams. The motivation behind the focus on GLOFs caused by moraine dams is the clear diagnostic evidence left behind by moraine-dam failures as well as the conventional link between climate change and moraine-dammed lake formation.
Dan Shugar, one of the authors of the study and a geoscientist at the University of Washington Tacoma, explained that these particular glacial lakes don’t tend to reform once they burst. “With ice-dammed lakes that burst, the glacier typically ‘heals’ the breach, and so they can reform and burst again and again,” he said, which allows for clear diagnostic evidence.
Adam Emmer, a fellow author from CzechGlobe, told GlacierHub that the research is the first attempt to link climate change with GLOF patterns on a global level. Christian Huggel, another author and geographer from the University of Zurich, added that this is no trivial task.
“It is reasonable to assume that glacier hazards will increase as the climate warms, and we were somewhat surprised to see that over the past century or so, there has not been a monotonic rise in outburst floods,” Shugar told GlacierHub. “The reality, as usual, is a bit more complicated.”
As simple as it would be to link warming climate to the increased frequency and severity of GLOFs, a number of factors go into a GLOF event. Differences in ground thermal conditions, for example, plus presence or absence of ground ice or permafrost all influence extreme weather. Seismic processes, topography, and glacial history also vary across mountain ranges.
However, as stated in the study, “although we know that GLOFs involve a complex set of dynamics… there must be a relationship here to climatic warming.” The scientists did conclude a lagged time response when it comes to GLOFs and climate change, with outburst flood frequency actually decreasing in recent decades since 1970.
“We suggest that outburst floods will become more frequent in response to contemporary warming, but that there is a lag built into the system,” Shugar explained. Thus, although an attribution of GLOFs to climate change is possible, a suite of factors influencing GLOF occurrence means scientists cannot adequately quantify the attribution as many might hope.
Ultimately, from assessing the timing of climate forcing, lag times in glacier recession, lake formation, and moraine-dam failure, the study predicts an increase in GLOF frequency in thecoming decades. But because of the assortment of factors involved in a GLOF event and glacier recession, the study states that GLOF frequency has not fluctuated directly in response to global climate change.
A close connection is certainly present, but the varying response times from mountain to mountain and region to region indicate that the relationship is hidden in messy response time dynamics.Prior to this study, no global database had been created that focused specifically on GLOFs related to the failure of moraine dams. The scientists argue that more studies exploring a global context of GLOFs are necessary to better understand the links to the changing climate and naturally-occurring variability. On the policy level, a better understanding of GLOFs’ relationship to present and future climate change is of great interest at both national and regional government levels due to the devastation potential of these events.
This research may also make its way to the courtroom. As Huggel explained to GlacierHub, “The study is certainly very relevant with respect to the ongoing legal case where a Peruvian sued German energy producers for the GLOF risks caused by anthropogenic climate change. In principle, more such court cases could follow.” There is also the question of loss and damages, and whether affected countries could receive compensation (or at least stronger assistance) for the resultant (or potential) damage.
Nepal is in the top 10 percent of countries in the world in terms of the frequency and severity of disasters. A recently published study in the journal Land has found that more than a quarter of the new houses in Pokhara, the second-largest city in Nepal, are being built in highly dangerous areas susceptible to multiple natural hazards, including glacier lake outburst floods (GLOFs) and avalanches.
The study lists a number of challenges for this rapidly-growing city, located in a region with a number of geological hazards. Most of the newly settled areas are located in agricultural areas. These are attractive to prospective residents, because they are flat and have owners who permit construction. However, these locations place new houses at great risk. The researchers indicate that this growth will continue until at least 2035.
Time-series Landsat images helped the researchers to explore the changes in land use and urbanization of the Pokhara from 1988 to 2016. The images were verified using extensive field visits to ensure accuracy. They served as a basis for projections into 2025 and 2035.
GLOFs are a major threat in Nepal, where 15 percent of the country is covered by the Himalayan mountains. This holds true for the Kaski District, where Pokhara is located. With rapid melting due to rising temperatures, glacier lakes are forming and increasing the level of risk seen in the surrounding areas.
Two of the most prominent issues in dealing with hazards such as this in Pokhara are uncertainty and perception. According to a report by the International Centre for Integrated Mountain Development (ICIMOD), “The probability of a lake outburst cannot be predicted with any reasonable level of certainty.” In addition, the views of the people at greatest risk are often more strongly influenced by, often inaccurate, media accounts than by scientific assessments.
Tony Oliver-Smith, a Professor Emeritus of Anthropology at the University of Florida, told GlacierHub about his work in hazard perception and resettling. “Some people may be generally aware of the risks, but the need for housing is so great that it may override such concerns,” he said. This kind of drive is typical for areas like this one that are undergoing rapid urbanization, often in unplanned environments. “Many people prefer to take their chances with hazards rather than government schemes to relocate them in more secure zones,” continued Oliver-Smith.
Further, cities like Pokhara often lack relevant legislation and regulatory capacity, appropriate agencies, and personnel both in qualifications and number, to enforce land use restrictions regarding housing location and safety, according to Oliver-Smith. A practical application of the study’s findings, he said, would be to develop appropriate legislation and funding to improve land use regulatory capacity, increase awareness of risk in vulnerable and exposed communities, and develop appropriate legislation and capacities in resettlement practice.
Natural hazards are on the rise globally, and with more people moving to more susceptible areas, the losses in human life and property are likely to increase. “As you put more and more people in harm’s way, you make a disaster out of something that before was just a natural event,” Klaus Jacob, a senior research scientist at Columbia University’s Lamont-Doherty Earth Observatory, told Live Science. To make matters more difficult, the study emphasizes that “developing countries with low-income and lower-middle economies experience greater loss and damage due to hazards.”
The researchers hope that their results “will assist future researchers and planners in developing sustainable expansion policies that may ensure disaster-resilient sustainable urban development of the study area.”
The study ultimately illuminates the common risk of hazards that people all over the world face. Luxury apartments being built along coastlines in flood-prone cities threatened by sea level rise continue to be built, similar to the continued urbanization in Pokhara. It’s a common situation, and finding solutions requires place-based, locally-specific information and research.
A longer version of this post appeared in the April 2017 issue of EcoAmericas.
When a flood from a mountain lake threatened to swamp the town of Carhuaz in the Peruvian Andes early one morning in April 2010, Víctor Rodríguez was the only person who knew. From his hut on a plain below the mountain, he heard the jet-like rumble as a block of ice calved off a glacier and crashed into the lake. The force of the fall produced a wave that swept over the earthen dike around the water body, called Lake 513, and cascaded down the steep slope. Rodríguez watched as the water swirled across the plain, swamping the catchment for the municipal water system, where he worked as caretaker. Picking up speed as it funneled into the Chucchún River, the torrent of water carrying mud and boulders swept away crops, livestock and some buildings. But it stopped just short of the town of about 12,000 people beside the Santa River, at the foot of Peru’s Cordillera Blanca.
The Destruction of an Early-Warning System
With climate change increasing the threat of such hazards, the Swiss government’s development agency, a Peruvian nonprofit, and a Swiss university teamed up to develop a high-tech early-warning system. By the end of 2013, lakeside sensors and cameras were in place above Carhuaz, with relay antennae that could transmit information quickly to a command center in the municipal offices. Once its kinks were worked out, the organizers of the project hoped the system could serve as a model for other towns that lie below glacial lakes. Then disaster struck again, this time in the form of a drought. Not only was rain scarce, but an unseasonable frost damaged crops. Rumors spread among residents of the farming communities around Carhuaz that the monitoring equipment at Lake 513 was preventing clouds from forming. Early one morning last November, several hundred people from the largely indigenous communities, where traditional Andean beliefs still hold sway, trekked up to the lake and tore down the system. Within a week, it rained.
The events raise questions about how to ensure that in areas where rural residents distrust technology, systems can be created to reliably warn those in the path of Carhuaz-style deluges, known as glacial lake outburst floods, or GLOFs. It also highlights tensions between growing urban areas and their rural neighbors— tensions that could deepen as dense development encroaches on agricultural land and city dwellers demand a larger share of water from threatened sources.
The destruction of the Carhuaz early-warning equipment came as a shock to the system’s developers, but in hindsight, signs of discontent had been building. During workshops in 2012, residents said they felt unprotected against outburst floods like the one in 2010, says Karen Price Ríos of CARE Peru, a nonprofit development organization that has been active in the area for several years. Price worked with local communities on the three-year early warning project, which was funded by the Swiss aid agency COSUDE and supported by researchers from the University of Zurich. The researchers drew up a risk map, showing the areas in varying degrees of danger from a mudslide like that of 2010, and devised evacuation routes, marking them with signs. The centerpiece of the project was the early-warning system on Mount Hualcán. If a block of ice broke from the glacier and crashed into Lake 513, it would trigger sensors that would turn on cameras and send an alert to local officials. They could then check the images from the cameras to verify the flood and sound an alarm.
The early warning would give local residents about half an hour to evacuate to safety zones. One monitoring station was installed at Lake 513, some 4,491 meters above sea level, with additional equipment several hundred meters higher. A repeater down in the valley boosted the signal before it reached the municipal offices in Carhuaz, at 2,641 meters above sea level. Another monitoring station— on the plain below Mount Hualcán, beside the upper part of a system of irrigation canals and the intake for Carhuaz’s drinking water system— gathered water-level and flow data from the Chucchún River.
The system was installed in 2012. In 2015, CARE’s Glacier Project in Carhuaz officially ended and the system was turned over to the Carhuaz provincial government headed by Mayor Jesús Caballero García, who had taken office in January. Though the head of the local disaster management office could monitor the system, the government lacked funds for specialized maintenance, Caballero says. “We didn’t have personnel trained to evaluate the entire system and say whether it was functioning,” he says.
In 2016, lack of rain became a more pressing concern than an outburst flood for farmers in the rural communities along the Santa River and its tributaries, including the Chucchún. It is not clear when people began to blame the equipment on Mount Hualcán, but in February 2016, one local leader asked Caballero to remove it. Two months later, vandals stole the cameras from the lakeside monitoring station. It might have been an ordinary theft, but observers note that it would be difficult to fence the specialized cameras in local black markets.
CARE and COSUDE agreed to replace the stolen cameras, but before arrangements could be made, leaders from several surrounding communities again demanded that the equipment be removed. A town hall-style meeting was scheduled for November to discuss the problem, but on Nov. 24, several hundred people from surrounding communities marched up the mountain to the lake. Caballero says he accompanied the group to persuade the protesters to leave the equipment in place, but after a few tense hours, they tore down what was left of the equipment beside the lake and the monitoring station on the plain below.
The Search for an Explanation
A few months later, some embarrassment seemed to have set in. It is difficult to find people who will admit to dismantling the equipment, although some will talk about the beliefs that led to the action— that the equipment “blew the clouds away,” or that it might have been placed there to benefit some outside interest, such as a mining company. It was not the first time equipment had been blamed for unfavorable weather near Carhuaz. Nearly two decades ago, farmers demanded that another researcher remove meteorological monitoring devices from the mountain. “People have a very close relationship with the mountains,” says geographer Christian Huggel of the University of Zurich. “The snow-capped peaks are living beings.”
With time, however, a more complex picture of the tensions over the Carhuaz early-warning system have emerged. In workshops with Glacier Project staff shortly after the 2010 outburst flood, people in both Carhuaz and the surrounding farming communities identified floods as the greatest natural hazard they faced. Climate change, it seemed, was on everyone’s mind. And in a study conducted during 2012-14, sociologist Luis Vicuña found that when discussing risks, people in the farming communities around Carhuaz spoke of climate change in virtually the same terms they had heard in the workshops. But when Vicuña changed the question slightly, he found that farmers were actually more concerned about their supply of irrigation water—whether they would continue to have enough water, and how much of a say they would have in managing it.
The water worries reflected tensions between the farming communities and the town of Carhuaz, where population growth has pushed the urban limits farther into the countryside. Farms have been shrinking as demand for food has been increasing, Vicuña says. The expanding urban population has increased demand for drinking water, too, says Lindón Mejía, who manages the city’s water and sanitation system. Since the timing of the Glacier Project happened to coincide with plans to expand Carhuaz’s potable water system, the drought may have exacerbated fears of more water being used for the urban area.
At the heart of those fears is concern that less irrigation water will be available for rural residents, who in addition face a lower risk of outburst-flood damage than town dwellers since they live on higher ground. Such tensions, combined with local urban and rural political dynamics, probably created fertile ground for rumors that led the crowd to tear down the monitoring stations, Vicuña says. Glacier Project staff made a concerted effort to forge consensus, meeting with people in the urban area and in the villages closest to Carhuaz. But many of those who climbed the mountain to pull down the monitoring equipment were from villages outside the area that would be in the path of an outburst flood from Lake 513. They knew little about the system and did not stand to benefit from it, Vicuña says. CARE and COSUDE decided not to reinstall the system at Lake 513, although COSUDE will finance a similar system around Santa Teresa, in the southern Peruvian region of Cusco.
Meanwhile, researchers, project staff and government officials puzzle over what could be done differently next time. Any such project, whether in Huaraz or elsewhere, should involve more extensive studies of local communities and political positions, Vicuña says. Another possibility might be to turn local residents into citizen scientists. Anthropologist Ben Orlove of Columbia University says the citizen scientists might be invited to help gather data and become part of the study, rather than simply witnessing the installation of instruments they don’t understand. And when new local government officials take office, attention must be paid to ensure that they will take responsibility for early-warning systems installed by their predecessors, says Martin Jaggi, COSUDE’s director of global cooperation programs.
The question will only become more critical. The Andes Mountains are home to the largest expanse of tropical glaciers in the world, but the ice fields have been shrinking significantly over the past half-century. A warmer climate means glaciers will continue to recede, and their meltwater will feed lakes high above valley towns. This, in turn, will heighten the risk of outburst floods.
Despite the dismantling of its early-warning equipment, Carhuaz is nevertheless better protected than it was before, Huggel says. Government officials and residents are more aware of the outburst-flood risks, evacuation routes are clear, and the personnel who keep watch over the city’s drinking water intake 24 hours a day can radio a message to the town in case of a flood. It is estimated that town residents can expect warnings 10 to 15 minutes before outburst waters arrive. That’s significantly less time to evacuate than the 30 minutes promised under the high-tech system originally envisioned, but the current plan still could be efficient, Huggel says. He adds: “The early warning system is much more than just instruments.”