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Flooding Glacial Lakes in Chile

Posted by on May 9, 2017 in Adaptation, All Posts, Featured Posts, Science | 0 comments

Flooding Glacial Lakes in Chile

Spread the News:ShareIt is a peaceful experience to walk near the glacial lake near Colonia Glacier, one of several prominent glacier lakes in Patagonia, Chile. The breeze on the lake helps you relax as you look out on the distant glaciers. In such a tranquil setting, it is hard to imagine that a glacial lake outburst flood (GLOFs) could pose a threat to the area. However, GLOFs have become a significant but poorly understood hazard of a warming global climate. The truth is, melting Colonia Glacier, located in the Northern Patagonian Ice Field, Chile, has caused dozens of GLOFs over the years. The lake near Colonia Glacier, Cachet II, has been drained frequently after unexpected floodings. The people living nearby are under constant threat of a sudden flood, which could completely destroy homes and livelihoods. Actually now, in the Chilean and Argentinean Andes, recent research by project member Pablo Iribarren Anacona has identified at least 31 glacial lakes have failed since the eighteenth century, producing over 100 GLOF events. “These lakes can be dangerous, and we need to take action,” Alton Byers, a geologist at the University of Colorado, told GlacierHub. A group of scientists concerned about GLOF risk have initiated a project, “Glacier Hazards in Chile,” which aims to answer key questions concerning past, present and future glacial hazards in Chile. One of the members is Ryan Wilson, a glaciologist at Aberystwyth University in the United Kingdom. “The project will assess the changing magnitude, frequency, and distribution of different glacial hazards in Chile under current and future global climate change,” Wilson explained to GlacierHub. At the moment, Wilson and the other researchers are focusing on understanding the processes that govern the development of GLOFs in Chile. The fieldwork of Wilson and his team was recently featured in Science. The them held a workshop at Aberystwyth University in July 2016, during which they discussed progress on their Chilean fieldwork, glacial lake mapping, glacial hazard assessment, outburst flood modeling and climate modeling. To assess GLOFs and GLOF risk, the team compiled a glacial lake inventory for the central and Patagonian Andes (1986 – 2016). Wilson said they used remote-sensing and fieldwork to find past GLOF sites around the major icefields, satellite glaciers and snow-and ice-capped volcanoes of Chile. “We have managed to use this lake inventory to inform field campaigns in February to two interesting glacial lake sites in Chile,” Wilson said. “We conducted aerial drone surveys and collected lake bathymetry data.” The team will next analyze flood hydrographs (a graph showing the rate of flow versus time past a specific point in a river) of selected former GLOFs and use these to establish the patterns of downstream impacts. They are proud of their work so far, which they hope to publish soon. Using the inventory across Chile, the team and local community  are able to assess the potential damage GLOFs can cause. Wilson et al. plan to “conduct numerical simulations of downstream impacts for selected potential GLOF sites using physically-based numerical flood models.” In collaboration with Chilean partners, this research will be used to develop early warning systems and raise awareness about quantified GLOF risks. Glacial hazards have threatened various commercial and governmental stakeholders across Chile, making GLOFs a pressing priority. The ultimate goal of the project is to provide a framework that can be applied to other lower income countries, since GLOFs pose threats in multiple countries. “We will make recommendations for GLOF hazard assessment protocols and mitigation strategies in lower income countries globally,” Wilson told GlacierHub. Spread the...

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Using Drones to Study Glaciers

Posted by on May 2, 2017 in All Posts, Featured Posts, Science | 0 comments

Using Drones to Study Glaciers

Spread the News:ShareUnderstanding the nature of glacial changes has become increasingly important as anthropogenic climate change alters their pace and extent. A new study published in The Cryosphere Discussions journal shows how Unmanned Aerial Vehicles (UAVs), commonly known as drones, can be used to do this in a relatively cheap, safe and accurate way. The study represents the first time a drone has been used to study a high-altitude tropical Andean glacier, offering insight into melt rates and glacial lake outburst flood (GLOF) hazards in Peru. The study was carried out by Oliver Wigmore and Bryan Mark, from the University of Colorado Boulder and Ohio State University respectively. It is part of a larger project aimed at understanding how climate change is affecting the hydrology of the region and how locals are adapting to these changes. The researchers used a custom-built hexa-multirotor drone (a drone with propellers on six arms) that weighed about 2kg to study changes in Llaca Glacier in the central Cordillera Blanca of the Peruvian Andes. Llaca, one of more than 700 glaciers in the Cordillera Blanca, was chosen for both logistical and scientific reasons. It covers an area of about 4.68 square kilometers in Huascaran National Park and spans an altitudinal range of about 6000 to 4500 meters above sea level. Like other glaciers within the Cordillera Blanca, it has been retreating rapidly because of anthropogenic climate change. To obtain footage, the researchers had to drive three hours on a winding, bumpy road from the nearest town, located about 10km away from the valley. “This was followed by a half–hour hike to the glacier,” Wigmore stated. To overcome some of the challenges of working in a remote, high-altitude region, the drone was custom-built using parts bought directly from manufacturers. In this case, a base was bought from a manufacturer. “I modified it by making the arms longer, lightening it with carbon fiber parts, and adding features like a GPS, sensor systems, infrared and thermal cameras, and other parts required for mapping,” Wigmore shared. Building their own drone allowed the researchers to repair it or replace parts when necessary, as sending it off to be repaired while in the field was not possible. It also allowed them to customize the drone to their needs. “No commercial manufacturers could promise that our equipment would work above an altitude of about 3000m, which is well below the glacier,” Wigmore said. Using drones to study glaciers has advantages over conventional methods in terms of access to glaciers and spatial and temporal resolutions of data. These advantages have been further enhanced by hardware and software developments, which have made drones a relatively cheap, safe and accurate remote sensing method for studying glaciers at a finer scale. For example, Wigmore can build a UAV for about $4000, compared to the high cost of airplanes and satellites also used in remote sensing. Wigmore and his team carried out aerial surveys of the glacier tongue (a long, narrow sheet of ice extended out from the end of the glacier) and the proglacial lake system (immediately beyond the margin of the glacier) in July 2014 and 2015. The drone was flown about 100 meters above the ice while hundreds of overlapping pictures were taken to provide 3-D images and depth perception. High resolution (<5cm) Digital Elevation Models (DEMs) and orthomosaics (mosaics photographs that have been geometrically corrected to obtain a uniform scale) were produced, revealing highly heterogeneous patterns of change across the glacier and the lake. The data also revealed that about 156,000 cubic meters of ice were lost within the study period. The...

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A New Glacier Grows at Mount St. Helens

Posted by on Apr 25, 2017 in All Posts, Featured Posts, News, Science | 0 comments

A New Glacier Grows at Mount St. Helens

Spread the News:Share “I grew up in the Yakima Valley (near Mount St. Helens). I was out fishing when I saw the lightning and dark cloud,” Flickr user vmf-214, who captured the eruption of Mount St. Helens in 1980, told GlacierHub. “It looked like a storm. I saw it as I pulled into the yard. Mom came out and said the mountain had blown.” He was describing the volcanic eruption that occurred at Mount St. Helens 37 years ago in May 1980. During that event, an eruption column rose into the sky, ultimately impacting 11 states in the U.S. But it wasn’t just the people who live in the area that were affected by the eruption: the glaciers of Mount St. Helens melted into nearby rivers, causing several mudslides. Cascades Volcano Observatory indicates that before the 1980 eruption, extensive glaciers had covered Mount St. Helens for several hundred thousand years. About 3,900 years ago, Mount St. Helens began to grow to its pre-eruption elevation and a high cone developed, allowing for substantial glacial formation. There were 11 major glaciers and several unnamed glaciers by May 18, 1980, according to the United States Geological Survey. But after the eruption and resultant landslide, about 70 percent of the glacier mass was removed from the mountainside. It was during the winter of 1980 to 1981, following the catastrophic eruption, that a new glacier, Crater Glacier, first emerged. “The glacier formed very fast, in a couple decades,” professor Regine Hock from the University of Alaska – Fairbanks told GlacierHub. It developed in a deep crater left by the eruption and landslide. Rock debris from the crater walls and avalanche snow created a thick deposit between the 1980–86 lava dome and crater walls. Shaped like an amphitheater, the crater protected the glacier from sunlight, allowing the glacier to expand extensively, according to the USGS. By September 1996, it was evident from photographs and monitoring that a new glacier had formed. Crater Glacier at Mount St. Helens is now considered one of the youngest glaciers on Earth. “The glacier tongues can be seen, descending either side of the degassing cone. Much of the glacier is covered by volcanic ash,” notes a recent report in Geography Review. By 2004, the report continues, the glacier covered around 0.36 square miles (0.93 km2), with two lobes wrapping around the lava dome in a horseshoe-like shape. Joseph S. Walder, a research hydrologist at the USGS, has been studying the latest eruptions of Mount St. Helens. When interviewed by GlacierHub, he attributed the formation of the Crater Glacier to three factors. “First, the crater acts as a sort of bowl that collects snow avalanching from the crater walls, so the accumulation rate is extremely high,” Walder said. “Secondly, the crater floor is in shadow most of the time. Last but not least, lots of rock material avalanches onto the crater floor, tending to cover and insulate accumulating snow.” Today, there are hiking tours available throughout the Mount St. Helens area. Climbing the mountain is like walking on the moon, with ash and boulders surrounding you. From the top, you can see the growing volcanic dome, steaming and smoking. Rodney Benson, an earth science teacher and blog writer at bigskywalker.com, hiked into the crater recently. “Some say the world will end in fire. Some say ice. What does this new glacier indicate?” he pondered.   As glaciers around the world recede as a result of climate change, the new glacier provides a fascinating context to explore interactions between volcanic processes, volcanic deposits and glacier behavior. The intensive monitoring programs led by the USGS...

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Roundup: Mélange, Ice Microstructures and Ice Caps

Posted by on Apr 17, 2017 in All Posts, Featured Posts, Roundup, Science | 0 comments

Roundup: Mélange, Ice Microstructures and Ice Caps

Spread the News:ShareRoundup: Mélange, Microstructures and Ice Caps Breakup of Mélange Increases Calving From the Journal Nature Communications: “At many marine-terminating glaciers, the breakup of mélange, a floating aggregation of sea ice and icebergs, has been accompanied by an increase in iceberg calving and ice mass loss. Previous studies have argued that mélange may suppress calving by exerting a buttressing force directly on the glacier terminus. In this study, I adapt a discrete element model to explicitly simulate mélange as a cohesive granular material. Simulations show that mélange laden with thick landfast sea ice produces enough resistance to shut down calving at the terminus. When sea ice within mélange thins, the buttressing force on the terminus is reduced and calving is more likely to occur.” Read more about the study here.     Ice Microstructures and Fabrics of Guliya Ice Cap From Journal Crystals: “This work is the first in the general natural ice literature to compare microstructures and fabrics of continent-type mountain ice in mid-low latitudes with polar ice in order to find out how they evolved based on similar fabric patterns of their vertically girdles. Microstructures and fabrics along the Guliya ice core on the Tibetan Plateau, China, were measured at a depth interval of approximately 10 m…  The thermal kinemics caused by the temperature can play a vital role in different stress cases to cast the similar or same fabric patterns. Normal grain growth, polygonization/rotation recrystallization, and migration recrystallization play roles of different importance at different depths.” Read more about the study here.   The Projected Demise of Barnes Ice Cap From American Geophysical Union: “As a remnant of the Laurentide Ice Sheet, Barnes Ice Cap owes its existence and present form in part to the climate of the last glacial period. The ice cap has been sustained in the present interglacial climate by its own topography through the mass balance-elevation feedback. A coupled mass balance and ice-flow model, forced by Coupled Model Intercomparison Project Phase 5 climate model output, projects that the current ice cap will likely disappear in the next 300 years. For greenhouse gas Representative Concentration Pathways of +2.6 to +8.5 Wm−2, the projected ice-cap survival times range from 150 to 530 years. Measured concentrations of cosmogenic radionuclides 10Be, 26Al, and 14C at sites exposed near the ice-cap margin suggest the pending disappearance of Barnes Ice Cap is very unusual in the last million years. The data and models together point to an exceptionally warm 21st century Arctic climate.” Read more about the study here.   Spread the...

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Explore the Homeland of the Emperor Penguin

Posted by on Apr 11, 2017 in All Posts, Featured Posts, Images, Science | 0 comments

Explore the Homeland of the Emperor Penguin

Spread the News:Share“Each winter, thousands of Emperor Penguins leave the ocean and start marching to a remote place in Antarctica for their breeding season. Blinded by blizzards and strong winds, only guided by their instincts, they march to an isolated region, that does not support life for most of the year…” – March of the Penguins The famous documentary March of the Penguins, directed by Luc Jacquet, earned the emperor penguin fanfare and admiration around the world. With their charismatic shape and loving nature, emperor penguins reside on the ice and in the ocean waters of Antarctica for the entirety of their lifespan, living on average from 15 to 20 years.  Satellite data has been used to help researchers better understand emperor penguin populations and how they respond to environmental variability, including the threat of a rapidly warming planet. But the information gleaned so far remains too limited to significantly help conservation efforts. Enter André Ancel, a researcher who led a team on a mission to study the remaining areas where emperor penguins might breed. His team recently published their findings in the journal Global Ecology and Conservation. March of the Penguins Official Trailer:   “The climate of our planet is undergoing regional and global changes, which are driving shifts in the distribution and phenology of many plants and animals,” Ancel writes in his paper. “We focus on the southern polar region, which includes one of the most rapidly warming areas of the planet. Among birds adapted to live in this extreme and variable environment, penguin species are the best known.” Even with their extreme adaption capabilities, emperor penguin breeding colonies are impacted by the fact that chicks often succumb to Antarctic elements. “Though they are one of the tallest and heaviest birds in the world, the survival rate of newborn emperor penguins is really low, only about 19 percent,” Shun Kuwashima, a PhD student at UCSC and self-declared penguin lover, explained. The purpose of Ansel et al.’s research was to predict how the species responds to climate change and to better understand the penguins’ biogeography, or geographical distribution. “There are only about 54 known breeding colonies,” notes Ancel, “many of which have not yet been comprehensively studied.” But finishing the research was a problem, considering that access to emperor penguin colonies remains limited. Getting accurate measurements on the size and location of the colonies relies on ground mapping and aerial photographs, which is “laborious, time consuming and costly,” according to Ancel. Even with the help of satellites, heavy cloud cover in the winter degrades the quality of images. Not to mention, the lack of light further complicates the collection of accurate data. In addition, the break-out of sea ice at the end of the breeding season can reduce the probability of detecting breeding colonies. Although the authors did not actually conduct any exploration or examine remote sensing data to locate new emperor penguin colonies, they used data on the location of known colonies to make their findings. Based on the behavioral patterns of penguins, including movement and dispersal, and on the availability of food, the researchers found “six regions potentially sheltering colonies of emperor penguins.” It is true that scientists have looked for emperor penguin colonies with satellite data in the past, but the method was limited. To make improvements and find potentially missing colonies, the team developed an approach for calculating separation distance between colonies. The approach determined the loxodromic separation distance (the shortest distance between two points on the surface of a sphere) between each pair of geographically adjacent colonies. Then, based on the fact that a breeding adult...

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Iceberg Scars on Seafloor Offer Clues to the Past

Posted by on Mar 28, 2017 in All Posts, Featured Posts, Science | 0 comments

Iceberg Scars on Seafloor Offer Clues to the Past

Spread the News:ShareMany people know the phrase “tip of the iceberg,” which acknowledges that most of the iceberg sits underwater, but few know what the bottom of an iceberg is capable of. Scientists recently found scars in the North Falkland Basin, north of the Falkland Islands, created by icebergs when they plowed into the seafloor. Known as scours, these u-to-v shaped scars can inform researchers about the Earth’s past in terms of climate, geography and ocean currents. Christopher Brown et al. recently published a paper on the topic in the journal Marine Geology, presenting their latest findings. In the paper, the researchers note that the icebergs responsible for the scours in the North Falkland Basin likely calved from glaciers in the Antarctic Peninsula. The size of the icebergs must have been immense in order for them to travel 2,000 kilometers and still leave marks on the seafloor hundreds of meters below. Given the freshness and reworking of the scours in the North Falkland Basin, researchers believe they likely formed during the Last Glacial Maximum (LGM), the time period when glacier and ice sheets dominated the globe and Antarctica was larger than it is today. Christopher Brown et al. later found and analyzed the scours using five high-quality 3-D seismic data sets covering an area of 1550 km². From analyzing the curvature of the scours, researchers can determine what kind of tides and currents were active thousands of years ago. Scours can also inform scientists about southern hemisphere climatology and ocean patterns. In the North Falkland Basin, Christopher Brown et al. found scours at depths ranging from 280 to 460 meters below sea level, while the depth of the basin reaches up to 2,500 meters. The researchers also located scours measuring nearly 10 meters deep, 38 kilometers long, and one kilometer wide. These scours may have meandered due to the rotation of the iceberg’s keel, or underside, when pushing into the seafloor. External forces that may have also caused a direction change can include ocean currents, tidal changes, subglacial calving, subglacial drainage and storms. Analyzing the location, curvature and orientation of scours provides scientists with insight into the Earth’s past. For example, the icebergs in the North Falkland Basin were likely carried by the East Falkland Current, an important northward current along the east side of Argentina that brings fresh, cold water north from Antarctica. This suggests that the current was active in the LGM and sheds light on the ocean-climate interactions in the southern hemisphere’s past. Christopher Brown et al. determined that a collection of icebergs may have even formed an iceberg “graveyard,” suggesting there may have been an ice bridge from Argentina to the Falkland Islands at some point in time. This means that the icebergs would have traveled on the east side of the Falkland Islands in order to get to the basin. In the northern hemisphere, scour marks have been found far away from where they were sourced, in the low-to-mid latitudes along the southern Atlantic United States coast, for example. In the southern hemisphere, few iceberg scours have been found outside of Antarctica, particularly in the mid-latitudes. The recent findings in the North Falkland Basin support the idea that icebergs could travel into warmer waters farther north of 50°S, the approximate location of the Falkland Islands. Rarely have icebergs been recorded north of the Falklands, but a few mega icebergs were spotted between 1979 and 2003. With much of the ocean floor still unexplored, there are likely more scours yet to be discovered that can tell scientists more about the planet’s past. As the scours in the North...

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