Posts Tagged "glof"

Roundup: Ice Filing, Seas Falling, Rivers Flooding

Posted by on Sep 12, 2016 in Experiences, Featured Posts, Roundup, Uncategorized | 0 comments

Roundup: Ice Filing, Seas Falling, Rivers Flooding

Spread the News:ShareThis Week’s Roundup: Glaciers are being collected in Antarctica, “quietly transforming the Earth’s surface” and causing floods A team of scientists, aware of the need to obtain ice cores from threatened glaciers, are working to create a glacier archive bank in Antarctica From CNRS News:  “By capturing various components of the atmosphere, ice constitutes an invaluable source of information with which to examine our past environment, to analyze climate change, and, above all, to understand our future. Today, the science of ice cores lets us study dozens of chemical components trapped in ice, such as gases, acids, heavy metals, radioactivity, and water isotopes, to name but a few…” “We plan to store the boxes in containers at a depth of 10 meters below the surface in order to maintain the glacier cores at an ambient temperature of – 54°C. The Antarctic is in fact an immense freezer with an ice sheet up to 4 kilometers thick, and is far removed from everything; in addition, it is not subject to any territorial disputes. The subterranean chamber will be large enough to house samples taken from between 15 and 20 glaciers.” Read on here.  Study finds that ancient melting glaciers are causing sea levels to drop in some places From Smithsonian Magazine: “But a new study out in the Journal of Geophysical Research shows that in places like Juneau, Alaska, the opposite is happening: sea levels are dropping about half an inch every year. How could this be? The answer lies in a phenomenon of melting glaciers and seesawing weight across the earth called ‘glacial isostatic adjustment.’ You may not know it, but the Last Ice Age is still quietly transforming the Earth’s surface and affecting everything from the length of our days to the topography of our countries.” For the full story, click here. Glacial flood emerges along Iceland’s Skaftá river From Iceland Magazine: “A small glacial flood is under way in Skaftá river in South Iceland. The Icelandic Met Office (IMO) warns travelers to stay away from the edge of the water as the flood water is carrying with it geothermal gases which can be dangerous….The discharge of Skaftá at Sveinstindur is presently 270 cubic metres per second. The flood is not expected to cause any downstream disruption.” Learn more about the flood by reading more here.         Spread the...

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Officials, Experts, Local People Visit a High-risk Glacier Lake

Posted by on Aug 25, 2016 in Adaptation, Featured Posts, News, Policy and Economics | 0 comments

Officials, Experts, Local People Visit a High-risk Glacier Lake

Spread the News:ShareOver 30 people, including government officials, researchers, students and journalists, recently visited Palcacocha, a lake at the foot of a large glacier high in the Peruvian Andes. This one-day trip was a tour that came the day after an international glacier conference held nearby. The group discussed natural hazards and water resources associated with the lake. The conversation revealed that a number of different agencies and organizations have claims to the lake, and that their concerns, though overlapping, differ in important ways, raising challenges for those who wish to manage it. These issues of governance are characteristic of the management of glacier lakes in other countries as well, including India, Nepal, Bhutan, Switzerland and Tajikistan. Lake Palcacocha, located about 20 kilometers northeast of the city of Huaraz at an elevation of 4550 meters above sea level, is well-known in Peru and beyond as the source of a major glacial lake outburst flood (GLOF). This event occurred in 1941, when a chunk of ice broke off the glacier above the lake, sending waves that destroyed the moraine that dammed the lake. The floodwaters, mixed with rock, mud and debris, rushed down the canyon and inundated Huaraz, located well below the lake at an elevation of 3050 meters. The death toll was high, exceeding 5000 by many accounts, and large areas of the city were destroyed. The residents of the city remain keenly aware of the risks presented by GLOFs, known as aluviones in Spanish. The visitors traveled up to the lake in buses and vans, hiking on foot to cover the final, and roughest, kilometer of the road. They assembled at the wall at the base of the lake that had been built in the 1940s to reinforce the moraine dam. The first person to speak was César Portocarrero, an engineer from the Peruvian National Institute for Research on Glaciers and Mountain Ecosystems, the group which organized the international conference. This institute, known by its Spanish acronym INAIGEM, is a branch of Peru’s Ministry of the Environment. It is charged with managing glacier issues in the country, including this lake. Portocarrero discussed the wall, indicating that it has been repaired several times after damage from earthquakes. He showed a sluice gate through which a number of plastic pipes were threaded. These serve to siphon water from the lake and pass it into the outlet river below, relying on gravity rather than pumps to move the water. By lowering the level of the lake, the agency also lowers the risk that waves in the lake (which could be produced by icefalls, avalanches, or earthquakes) would overtop the wall and create another GLOF. Portocarrero indicated as well that an intake valve further downstream directs the water from the river to the city of Huaraz. This lake supplies the city with nearly half its water. The key goal, he emphasized, was to keep the lake level low. He mentioned that glacier melt was particularly heavy in January, due to high temperatures associated with an El Niño event. The lake was so high that the siphon pipes had to be removed, allowing the maximum possible flow through the sluice gate. It took several months after the excess water was drained to thread the pipes through the gate and reinstall them. The second person to speak was Eloy Alzamora Morales, the mayor of the district of Independencia, the administrative unit in which the lake is located. He emphasized the importance of a multisectoral approach that would link disaster risk reduction with sustainable water use, providing potable water to Huaraz and to rural areas above the...

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Roundup: GLOFs, Presidential Warnings, and Glacial Lakes

Posted by on Aug 22, 2016 in All Posts, Featured Posts, Roundup | 0 comments

Roundup: GLOFs, Presidential Warnings, and Glacial Lakes

Spread the News:ShareObama: Climate Change ‘Could Mean No More Glaciers In Glacier National Park,’ Statue of Liberty From Breitbart:  “During Saturday’s Weekly Address, President Obama stated, “the threat of climate change means that protecting our public lands and waters is more important than ever. Rising temperatures could mean no more glaciers in Glacier National Park. No more Joshua Trees in Joshua Tree National Park. Rising seas could destroy vital ecosystems in the Everglades, even threaten Ellis Island and the Statue of Liberty.” To read the full transcript of the President’s Weekly Address, click here.   Melting Glaciers Pose Threat Beyond Water Scarcity: Floods From VOA News:   “The tropical glaciers of South America are dying from soot and rising temperatures, threatening water supplies to communities that have depended on them for centuries. But experts say that the slow process measured in inches of glacial retreat per year also can lead to a sudden, dramatic tragedy. The melting of glaciers like Peru’s Pastoruri has put cities like Huaraz, located downslope from the glacier about 35 miles (55 kilometers) away, at risk from what scientists call a ‘GLOF’ — Glacial Lake Outburst Flood.” Click here to read more about the risk of glacial lake outburst floods from GlacierHub’s founder and editor, Ben Orlove.   Yukon has a new lake, thanks to a retreating glacier From CBC News:  “Yukon has lost a river, and now gained a lake, thanks to the retreating Kaskawulsh glacier. Geologists and hikers first noticed earlier this summer that the Slims River, which for centuries had delivered melt water from the glacier to Kluane Lake, had disappeared — the glacial run-off was now being sent in a different direction. Now, the level of Kluane Lake has dropped enough to turn the remote Cultus Bay, on the east side of the lake, into Cultus Lake. A narrow channel of water that once connected the bay to the larger lake is gone, exposing a wide gravel bar between the two.” To read more, click here. Spread the...

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New Study Offers Window into Glacial Lake Outburst Floods

Posted by on Aug 11, 2016 in All Posts, Featured Posts, Science | 0 comments

New Study Offers Window into Glacial Lake Outburst Floods

Spread the News:ShareA recent geological study has shed some light on the cause of a major, yet elusive destructive natural hazard triggered by failed natural dams holding back glacial lakes. The findings show how previously unrecognized factors like thinning glacier ice and moisture levels in the ground surrounding a lake can determine the size and frequency of Glacier Lake Outburst Floods, or GLOFs. The risks of these glacial floods are generally considered increasingly acute across the world, as warming atmospheric temperatures prompt ice and snow on mountain ranges to retreat and to swell glacial lakes. Landslides in moraines as triggers of glacial lake outburst floods: example from Palcacocha Lake (Cordillera Blanca, Peru), published in  Landslides in July 2016, centers its study on Lake Palcacocha in the Cordillera Blanca mountain region of central Peru.  Since Palcacocha is one of almost 600 lakes in the Cordillera Blanca mountain range dammed by glacial moraines, the population of the region lives under serious threat of GLOFs. The Landslides article is a step in understanding a previously understudied geological phenomenon.  As little as five years ago scientists acknowledged the lack of research on the subject. “We don’t really have the scientific evidence of these slopes breaking off and moraine stability… but personal observations are suggesting there are a lot of those…” said Ph.D. environmental historian Mark Carey in a 2011 video where he describes GOLFs.   Glacial Lake Outburst Flood risks do not always emanate from mountain glacier meltwater that flows downstream. As this study shows,  in some instances, trillions of gallons of water can be trapped by a moraine, a formation of mixed rock, which forms a natural dam.  A weakening over time, or a sudden event, such as a landslide, could then result in the moraine dam’s collapse. The massive amount of water is suddenly then released, and a wall of debris-filled liquid speeds down the mountainside with a destructive force capable of leveling entire city blocks. GLOFs have presented an ongoing risk to people and their homes dating back to 1703, especially in the Cordillera Blanca region, according to United States Geological Survey records.  In December of 1941, a breach in the glacial moraine restraining Palcacocha Lake led to the destruction of a significant portion of the city of Huaraz and killed approximately 5,000 people. Scientists and government agencies, like the Control Commission of Cordillera Blanca Lakes created by the Peruvian government following the 1941 GLOF, have recognized the need to better understand and control GLOFs.  The study found that as global temperatures rise and glaciers retreat, greater amounts of glacier melt water will continue to fill up mountain lakes, chucks of ice will fall off glaciers, and  wetter moraines will become  more prone to landslides. The team of mostly Czech geologists and hydrologists (J. Klimeš; J. Novotný; I. Novotná; V. Vilímek; A. Emmer; M. Kusák; F. Hartvich) along with Spanish, Peruvian and Swiss scientists (B. Jordán de Urries; A. Cochachin Rapre; H. Frey and T. Strozzi) investigated the ability of a glacial moraine’s slope to stay intact, called shear strength, and modeled the potential of landslides and falling ice to cause GLOFs. After extensive field investigations, calculations and research into historical events, the study found several causal factors that can determine the severity of a GLOF.  These include size and angle of entry of a landslide,  shape and depth of the glacial lake, glacier thickness and human preventative engineering such as canals and supporting dams.  Frequency and size of a landslide is determined by the stability of surface material, a characteristic called shear strength, which can be influenced by something as subtle as the crystalline shape of the predominant mineral in the rock. The scientists determined that waves caused...

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First global analysis of the societal impacts of glacier floods

Posted by on Jul 28, 2016 in All Posts, Communities, Featured Posts, Interviews, Science | 0 comments

First global analysis of the societal impacts of glacier floods

Spread the News:ShareTwo British researchers recently published the first global inventory and damage assessment of the societal consequences incurred by glacial lake outburst floods (GLOFs). They revealed that glacial lake outburst floods (GLOFs) have been declining in frequency since the mid-1990s, with the majority released by ice dam failures. Glacial hazard specialists Jonathan Carrivick and Fiona Tweed spent 18 months scouring the records of over 1,348 GLOFs, determining that such floods have definitely claimed over 12,400 lives since the medieval period. Their work stems from a need to strengthen data on glacier lakes. “There was very very little quantitative data out there on the importance of glacier lakes, from a societal point of view,” Carrivick said in an interview with GlacierHub. He explained that this recent paper was a natural progression from his earlier research, which focused on modelling hydrological, geological and geomorphological processes. Based purely on frequency, Carrivick and Tweed found that north-west North America (mainly Alaska), the European Alps (mainly Switzerland), and Iceland are the “most susceptible regions” to GLOFs. However, the impacts of these events have have often been minimal, as they occur in sparsely populated, remote regions, and in places where resilience is high. The greatest damage has been inflicted upon Nepal and Switzerland — respectively accounting for 22 percent and 17 percent of the global total damage reported. When Carrivick applied the normalized ‘Damage Index,’ which considered GDPs of the affected country (used as a crude proxy for ability to mitigate, manage and recover), he found that Iceland, Bhutan and Nepal have suffered the “greatest national-level economic consequences of glacier flood impacts.” Historically, Asian and South American GLOFs have been the deadliest, taking the lives of 6,300 and 5,745 individuals since 1560 respectively. However, these figures are dominated by only two catastrophes, which accounted for 88 percent of the 12,445 fatalities confirmed by Carrivick and Tweed. The first, in December 1941, saw over 5,000 Peruvians perish in Huaraz, when a landslide cascaded into the glacial Lake Palcacocha. The second event, swept away more than 6,000 Indians from across Uttarakhand in June 2013, as torrential rains triggered outburst floods and landslides. The study’s authors adopted a method for normalizing damage assessments new to GLOF hazard analysis, striving to fairly compare the cataclysmic impacts of outburst flooding on communities around the world. They found that there has actually been a decline in number of floods since the 1990s, which was surprising to the researchers, given that a 2013 study which they had conducted found that the number and size of glacial lakes has increased, as the world’s ice masses have wasted. Carrivick stated that he was “very interested in the fact that, apparently, so few glaciers have lakes that have burst [0.7% of the total], on a global scale.” He added, “it beggars belief that there isn’t a higher percentage of those lakes that have burst at some point.” In their paper, the pair suggest that the “apparent decline” could be attributed to improved successful stabilisation efforts, natural resilience, greater awareness and preparedness in threatened communities, or declined number of GLOFs from ice-dammed lakes. An additional factor may be that some glacial floods are missing from the English-language record. Carrivick revealed, “We have a contact in China who says that there’s a lot of unpublished floods…that individual has not been able to send us the data yet.” Government restrictions on the flow of potentially sensitive information has contributed to this partial release of data. Carrivick also noted that new data is continually being published, in many cases in foreign languages. He referenced a recent issue of the Geological Journal, which...

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