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Earthquake in Greenland Triggers Fatal Landslide-Induced Tsunami

Posted by on Jun 28, 2017 in All Posts, Featured Posts, News | 0 comments

Earthquake in Greenland Triggers Fatal Landslide-Induced Tsunami

Spread the News:ShareThis post, written by David Jacobson, appeared earlier this month on the website Temblor. It has been lightly edited. A M=4.1 earthquake which took place on June 17 on Greenland’s western coast caused a massive landslide, triggering a tsunami that inundated small settlements on the coast. At this stage, four people are feared to have died, nine others were injured, and 11 buildings were destroyed. In the hardest hit village, Nuugaatsiag, which is home to around 100 people, 40 people were evacuated to Nuugaatsiag, the eleventh-largest town in Greenland. While this earthquake appears to be tectonic in nature, according to Meredith Nettles of the Lamont-Doherty Earth Observatory at Columbia University, Greenland also experiences what are known as glacial earthquakes. Glacial earthquakes are a relatively new class of seismic event, often linked to the calving of large outlet glaciers. While this type of event has also been observed in Antarctica, the majority have been recorded off the coast of Greenland, and show a strong seasonality, with most of them occurring late in the summer. Because glacial earthquakes have a different mechanism than normal earthquakes, standard earthquake monitoring techniques cannot be used to detect them, which explains why they were not known about until 2003. Additionally, while a tectonic M=5 quake typically lasts about 2 seconds, a comparable M=5 glacial earthquake can emit long-period (greater than 30 seconds) seismic waves. It is because of this that they have a separate classification. In order for a glacial earthquake to occur, a large-scale calving event has to take place. When a glacier calves, there is a sudden change in glacial mass and motion. While a glacier is technically a river of ice, meaning it slowly flows downhill, when a large calving event takes place, there is a brief period when horizontal motion reverses. Couple this with a downward deflection of the glacier’s terminus, which causes an upward force on earth’s surface, and you have the recipe for a glacial earthquake. These earthquakes tend to be M=4.6-5.1. Despite the fact that this tectonic quake was by no means large, it was big enough to trigger a massive landslide into the ocean, and the ensuing displacement of water was enough to form a tsunami that devastated parts of Nuugaatsiag. Nettles noted, “The M=4.1 earthquake does not explain the large, long-period (slow) seismic signal detected by seismometers around the globe. The long-period signal appears to be due to a landslide, and the time of the long-period signal is later than the time of the high-frequency (earthquake) signal. It is possible the earthquake triggered the landslide.” What this means is that both the earthquake and landslide generated seismic signals, but that the earthquake signal appeared first, suggesting the quake triggered the slide. The video below shows a view of the landslide, while the photos below show the landslide and the devastation caused by the tsunami.       A helicopter video of the landslide that triggered the deadly tsunami in Greenland:         Spread the...

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Glacier Countries Condemn Trump’s Withdrawal from the Paris Agreement

Posted by on Jun 19, 2017 in All Posts, Featured Posts, News, Policy and Economics, Uncategorized | 0 comments

Glacier Countries Condemn Trump’s Withdrawal from the Paris Agreement

Spread the News:ShareCountries around the world were quick to condemn Donald Trump when he announced his decision to withdraw the U.S. from the Paris Agreement. Unsurprisingly, small countries with glaciers, with their direct experience of climate change, have joined this round of condemnation. However, the details varied from country to country. And relatively few voices in these countries have emphasized the connection between their own experience of climate change and their opposition to Trump’s action.   Latin America The strongest reaction came from Peru, where the national government issued an official declaration on June 1, within hours of Trump’s announcement. It stated “The Government of Peru receives with concern and disappointment the announcement made by the Government of the United States of America to denounce the Paris Agreement on Climate Change.” The declaration underscored the actions of Peru in hosting a major international climate meeting that led up to the Paris Agreement, and in being the first country in Latin America to ratify it. Newspapers in Peru also expressed their condemnation. A center-left newspaper, La República, stated on June 2 that Trump “has turned his back on the world.” The more conservative El Comercio emphasized that the U.S. was isolating itself from the other nations of the world. Jesús Gómez López, the director of Peru’s Huascarán National Park, where the majority of the country’s glaciers are located, told GlacierHub, “This decision of the Trump administration is regrettable. It is a great concern that it works against progress that has been made in reducing greenhouse gas emissions.” He mentioned his particular concern about the rapid loss of glaciers in tropical areas. Chile, another South American country with large glaciers, also issued an official response. On June 1, the Foreign Minister issued a statement indicating the country’s “great concern and deep disappointment.” It emphasized Chile’s vulnerability, citing floods and forest fires, and reiterated the country’s commitment to reducing its emissions of greenhouse gasses. Greenpeace Chile spoke against Trump’s decision and used the occasion to launch a petition to oppose oil exploration. The country director of Greenpeace, Matías Asun, called for a national law to protect glaciers.   Europe European nations also responded strongly to Trump’s action. In Iceland, the European country where glaciers occupy the largest proportion of the national territory, the Minister of the Environment, Björt Ólafsdóttir, expressed her disappointment with Trump’s decision on June 1. She also recognized that some states, like California, were taking independent action in alignment with the Paris Agreement. Dagur B. Eggertsson, the mayor of Reykjavik, Iceland’s capital and largest city, offered a visible response. He announced on June 2 that the city would shine green light on  Harpa–its music hall and conference center, and an iconic symbol of contemporary Iceland–as a sign of commitment to the Paris Agreement. Several Norwegians expressed their concern to GlacierHub. Marianne Lien, an anthropologist at the University of Oslo, wrote “Trump news is no longer even funny or interesting. His withdrawal from the Paris agreement is just another move in a series of events that makes the US more and more marginal in world politics, and especially regarding global climate policy. This opens up a space for others to take a lead, such as the EU and China. Perhaps Trumps withdrawal is a wake-up call to some, and could inadvertently raise even more awareness about the politics of climate change.” Rasmus Bertelsen, the Barents Chair in Politics at the Arctic University of Norway in Tromsø, linked Norway and Iceland with Sweden, Denmark and Finland. He stated “President Trump’s speech withdrawing from the Paris Agreement marks a watershed in post-World War II...

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Roundup: A Shrinking Lake, a Deepening Lake, and Ice below Sea Level

Posted by on Jun 19, 2017 in All Posts, Featured Posts, News, Roundup, Science | 0 comments

Roundup: A Shrinking Lake, a Deepening Lake, and Ice below Sea Level

Spread the News:ShareGlacial Retreat Shrinks Yukon’s Largest Lake From CBC News: “Kluane MLA Wade Istchenko says receding water levels on Kluane Lake are posing a problem for his constituents — and he wants the government to respond. The lake level first dropped last year, after the Kaskawulsh Glacier retreated so much that its meltwater abruptly switched direction, away from Kluane Lake. Researchers have blamed climate change for the geologic phenomenon referred to as ‘river piracy’.” You can read more about how Istchenko proposes the legislature respond here.   Spillway Lake in Nepal Deepens From Water: “Since the 1950s, many debris-covered glaciers in the Nepalese Himalaya have developed large terminal moraine-dammed supraglacial lakes, which grow through expansion and deepening on the surface of a glacier. As temperatures continue to rise and lakes continue to grow in area and volume, they pose a flooding risk to the Sherpa villages down-valley.” Learn more about how the Ngozumpa Glacier’s terminal lake is growing here.   Melting an Ice Sheet from Below From Nature: “Because the East Antarctic Ice Sheet seems so cold and isolated, researchers thought that it had been stable in the past and was unlikely to change in the future — a stark contrast to the much smaller West Antarctic Ice Sheet, which has raised alarms because many of its glaciers are rapidly retreating. In the past few years, however, “almost everything we thought we knew about East Antarctica has turned out to be wrong”, says Tas van Ommen, a glaciologist at the Australian Antarctic Division in Kingston, near Hobart. By flying across the continent on planes with instruments that probe beneath the ice, his team found that a large fraction of East Antarctica is well below sea level, which makes it more vulnerable to the warming ocean than previously thought. The researchers also uncovered clues that the massive Totten glacier, which holds about as much ice as West Antarctica, has repeatedly shrunk and grown in the past — another sign that it could retreat in the future.” Read more about uncertainty in the East Antarctic here.     Spread the...

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Roundup: Clean Climbing, Subglacial Discharges, and Nepali Youth

Posted by on Jun 12, 2017 in All Posts, Featured Posts, News | 0 comments

Roundup: Clean Climbing, Subglacial Discharges, and Nepali Youth

Spread the News:ShareDenali NPS Encourages ‘Clean Climbing’ From the National Park Service: “A decade of scientific research has produced conclusive results – human waste left behind by climbers is polluting the streams and rivers that flow out of the Kahiltna Glacier. Our ultimate goal is to require 100% removal of all human waste from Denali, and we will continually strive to develop practical, working solutions to achieve this goal. We will be learning from your participation how to best to manage this next phase of ‘Clean Climbing’ on Denali.” You can read more about how the Park Service is encouraging these practices here.   A Forager’s Paradise for Seabirds From Scientific Reports: “We found that tidewater glacier bays were important foraging areas for surface feeding seabirds, kittiwakes in particular. Such sites, rich in easily available food and situated in the fjord close to colonies, are used as supplementary/contingency feeding grounds by seabirds that otherwise forage outside the fjord. For kittiwakes these areas are of great significance, at least temporarily. Such an opportunity for emergency feeding close to the colony when weather conditions beyond the fjord are bad may increase the breeding success of birds and buffer the adverse consequences of climatic and oceanographic changes.” Find out more about why these areas are so abundant here.   Nepali Youth Appeal to Trump From The Himalayan Times: “Nepali Youth and Mountain Community Dwellers have appealed to U.S. President Donald Trump to take back his decision to pull out of the 2015 Paris Agreement on Climate Change. An appeal letter was submitted to the U.S. embassy here on Monday by Nepali youth representing people living in the foothills of the Himalayan peaks, including the tallest Mount Everest.  The letter was handed over to deputy political and economic chief of the U.S. embassy Stephanie Reed.” Read more about why Nepalese people are so concerned over Trump’s decision here. Spread the...

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Palcacocha Icefalls Demonstrate Hazard Vulnerabilities in Peru

Posted by on Jun 6, 2017 in All Posts, Featured Posts, News, Policy and Economics, Science | 1 comment

Palcacocha Icefalls Demonstrate Hazard Vulnerabilities in Peru

Spread the News:ShareRecent Calving Events at Lake Palcacocha In the last week, calving events at Lake Palcacocha in the Peruvian Andes released masses of ice from a glacier on Mount Pucaranra. The ice fell into the lake, sending waves across the lake that destroyed infrastructure designed to prevent dangerous outburst floods. Fortunately, the waves were not high enough to overtop the moraine dam and send floodwaters downstream, where they could have taken many lives and damaged urban infrastructure. A glacial lake outburst flood from Palcacocha devastated Huaraz, the largest city in the region, in 1941, killing about 5,000 people. Other, more recent, glacier floods in the region have also been very destructive. Marco Zapata, the director of glacier research at INAIGEM, the Peruvian National Institute of Research on Glaciers and Mountain Ecosystems, spoke about the events recently in a press conference reported in the Peruvian daily El Comercio. A Spanish-language video of the full press conference is available online. Zapata indicated that the calving event occurred around 8 p.m. on May 31. The resulting waves, three meters in height, were strong enough to move and damage ten large pipes, rendering them inoperable. These pipes, known locally as “syphons,” are designed to draw water from the lake at times when its level is high; in this way, they were thought to reduce flood risk significantly. They had been a point of local pride, seen as a successful application of modern technology to protect against the dangers to which the region has long been subject. Zapata mentioned that the waves also destroyed several gauges and a sensor which measures lake levels. And the event was not an isolated one, at least according to a regional newspaper, which reported a second calving event at 5:40 a.m. on June 2. Representatives of INAIGEM and two other organizations, the National Water Authority and the local municipality of Independencia, visited the lake a few days later. They found that the workers on Pucarthe site had restored two of the drainage pipes. These officials anticipated that the other eight will soon be functional.  Zapata and the other authorities called for increased investment in infrastructure at the lake to reduce the risks of a flood. They estimated that an expenditure of US $6 million would prevent about $2.5 billion in potential damages, including a hydroelectric plant and irrigation facilities on Peru’s desert coast; it would also protect the lives of the 50,000 people who live in the potential flood zone. The Causes of the Calving Events These events were not entirely unexpected. Marcelo Somos Valenzuela, a postdoctoral fellow at the Northeast Climate Science Center at the University of Massachusetts, is the lead author of a study, published last year in the journal Hydrology and Earth System Sciences, which concluded “there is consensus among local authorities, scientists and specialists that Lake Palcacocha represents a glacier lake outburst flood hazard with potentially high destructive impact on Huaraz.” This paper also stated that a “small avalanche” like the ones that recently occurred are “the highest likelihood event” and that they would “produce significantly less inundation.”  Somos Valenzuela wrote to GlacierHub, “There are empirical models and hydrodynamic models which provide estimates of the height of the wave in the lake… In this case, it seems that the ice-fall was small, and 3 meters is a reasonable estimate of the wave height.” Moreover, several sources indicated high risks at this time of year. Noah Walker-Crawford, an anthropologist at the University of Manchester, spoke recently with the workers at the drainage site at the lake. He wrote to GlacierHub, “According to the people who work at the...

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Roundup: Avalanches, Droughts, and a Sherpa protest

Posted by on Jun 5, 2017 in All Posts, Featured Posts, News, Roundup, Science | 0 comments

Roundup: Avalanches, Droughts, and a Sherpa protest

Spread the News:ShareRoundup: Avalanches, Droughts, and Sherpas   Calving Event in Peruvian Lake Damages Infrastructure Designed to Reduce Flood Risk From El Comercio: “Small ice avalanches have damaged the system of syphons in Lake Palcacocha, Ancash, Peru. Marco Zapata, the head of the Glacier Research Unit at INAIGEM, stated that on May 31, around 8 p.m., a calving event occurred at the glacier front on Mount Pucaranra, releasing ice into the lake. This event generated waves 3 meters in height, which caused 10 of the syphons to shift and which destroyed three gauges and a water level sensor.” Find out more about Lake Palcacocha and ice avalanches here.   Asian Glaciers Fight Against Drought From Nature: “The high mountains of Asia… have the highest concentration of glaciers globally, and 800 million people depend in part on meltwater from them. Water stress makes this region vulnerable economically and socially to drought, but glaciers are a uniquely drought-resilient source of water. Glaciers provide summer meltwater to rivers and aquifers that is sufficient for the basic needs of 136 million people… Predicted glacier loss would add considerably to drought-related water stress. Such additional water stress increases the risk of social instability, conflict and sudden, uncontrolled population migrations triggered by water scarcity, which is already associated with the large and rapidly growing populations and hydro-economies of these basins.” Find out more about Asia’s drought-resilient glaciers here.   Sherpas Demand Summit Certificates at Protest From The Himalayan Times: “Hundreds of sherpa climbers who met at Mt Everest base camp [in May] asked the government to immediately issue their summit certificates… Sherpa climbers who made it to the top of several peaks, including Mt Everest, have not been getting their summit certificates since last year after the government refused to approve their ascents citing a clause of the Mountaineering Expedition Regulation that bars them from obtaining such certificates… For most of the foreign climbers, summiting a mountain without sherpas’ help is almost impossible in Nepal… The new amendment to the regulation will recognize high-altitude workers as a part of the expedition to get certificates.” Find out more about the Sherpa protest and resolution here.     Spread the...

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