Posts Tagged "patagonia"

Photo Friday: Inside Glacier Caves

Posted by on May 26, 2017 in All Posts, Featured Posts, Images, Tourism | 0 comments

Photo Friday: Inside Glacier Caves

Spread the News:ShareCaves can form within glaciers as a result of water running through or under a glacier. They are often called ice caves, but the term more accurately describes caves in bedrock that contain ice throughout the year. Water usually forms on the glacier’s surface through melting, before flowing down a moulin (vertical to nearly vertical shafts within glaciers or ice sheets) to the base of the glacier. Glacier caves can also form as a result of geothermal heat from hotsprings or volcanic vents beneath glaciers, such as the Kverkfjöll glacier cave in Vatnajökull glacier in Iceland, or where glaciers meet a body of water, with wave action. Glacier caves can collapse or disappear because of glacier retreat. For example, the Paradise Ice Caves on Mount Rainier in Washington had 8.23 miles of passages in 1978. However, it collapsed in the 1990s, and the section of the glacier that contained the caves retreated between 2004 and 2006. Prior to collapse, caves can be used to access the interior of glaciers for research purposes, with the study of glacier caves sometimes known as glaciospeleology. Others also serve as popular tourist attractions due to their beauty.           Sandy Glacier Caves, Mount Hood, Oregon, CA – Photograph via Josh Hydeman pic.twitter.com/hWEPMllbqS — Life on Earth (@planetepics) January 31, 2016 Read about a time when Putin visited a glacier cave here. Spread the...

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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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Krill Contribute to Ocean Carbon Storage in Patagonia

Posted by on Dec 27, 2016 in All Posts, Featured Posts, Science | 0 comments

Krill Contribute to Ocean Carbon Storage in Patagonia

Spread the News:ShareWaters in the sub-Antarctic region of Chilean Patagonia are fed by glaciers in one of the largest freshwater systems on Earth, the North and South Patagonian Icefields. A recent study published in Marine Ecology Progress Series found that Euphasia vallentini, the most abundant species of krill in Chilean Patagonian waters, play a key role in food webs. The study also discovered that this species of krill helps to sequester carbon in the oceans— they consume plankton, which take in carbon during photosynthesis, and discharge some of the carbon into deeper ocean waters through the production of fast-sinking fecal pellets. This is increasingly important as atmospheric carbon concentrations rise, as it contributes to the role of the oceans as a carbon sink. Krill are small, shrimp-like crustaceans that are found in all of the world’s oceans. In an interview with GlacierHub, Humberto E. González, the lead author of the study from the Austral University of Chile, explained that krill form “a trophic [related to food and nutrition] bridge between the microbial community [bacteria, nanoplankton, microzooplankton] and the upper trophic layers [seals, whales, penguins, etc.]. Thus, they play a pivotal role in trophic flows.” The study by González et al. focused on the region between the Magellan Strait and Cape Horn because of the unique biological, chemical and physical conditions created by the hydrological input from three different sources: nutrient-rich Pacific and Atlantic Sub-Antarctic Waters (waters that lie between 46°– 60° south of the Equator), and cold and nutrient depleted freshwater from Patagonian rivers and glaciers. Waters that are more saline or that are colder have higher densities. However, as explained in the study, the effect of salinity exceeds the effect of temperature on density within this region, giving rise to strong saline stratification in the mixture of oceanic and freshwater terrestrial environments. This reduces the movement of important species between the benthic (the lowest level) and pelagic (open water) ecosystems in southern Patagonia. The stratification also reduces upward and downward mixing of ocean water. This reduces carbon fluxes in the region, as the transport of carbon dioxide to deeper parts of the ocean through diffusion across layers occurs more slowly than the circulation of ocean waters with different carbon dioxide concentrations. The team of scientists embarked on a research cruise in the region in October and November 2010, collecting chemical and biological samples at about forty different stations. Using a variety of techniques, they studied features such as the types and distribution of organic carbon in the waters, and the abundance and diet of E. vallentini. All this was done to better understand the role of E. vallentini in the region’s food web structures and in the transport of carbon to deeper layers of the ocean despite strong stratification. In conversation with GlacierHub, González stated that “the species of the genus Euphausia (a functional group of zooplankton) play a paramount role in many disparate environments from high to low latitude ecosystems. Euphausia superba in the Southern Ocean and Euphausia mucronata in the Humboldt Current System are some examples.” In this study, González et al. found that E. vallentini play a similarly important role in Southern Chilean Patagonia, consuming a range of plankton from nano- to phytoplankton and forming the dominant prey of several fish, penguin and whale species. The study also found that E. vallentini play an important role in passive fluxes of carbon through the sequestration of carbon in fast-sinking fecal pellets, or poop. The plankton ingested by E. vallentini takes in carbon dioxide during photosynthesis, and about a quarter of the plankton ingested by E. vallentini...

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Patagonian Ice Holds the Key to Unlocking the Past

Posted by on Nov 2, 2016 in All Posts, Communities, Featured Posts, Images, Science, Tourism | 0 comments

Patagonian Ice Holds the Key to Unlocking the Past

Spread the News:ShareA research team recently conducted a study in the Northern Patagonia Ice Field (NPI) to uncover some of the mystery behind Earth’s ancient climate. Along the way, the team made important observations about the current state of glacial ice thinning and climate change. Through their investigation of ancient paleoclimates (climates prevalent in the geological past), the scientists were able to identify time periods where major glacial growth and decline occurred in the Patagonian Ice Field, contributing important information to our understanding of our planet’s climate following the last ice age. Developing a strong comprehension of glacial advance and retreat over the last 10,000 years in places like the Patagonian Ice Field provides the scientific community with tools to augment our understanding of the past, as the planet’s climate is intrinsically related to its ecology at any given point in our recent geological history. Patagonia hosts a wide variety of largely untouched landscapes, possessing a range of environments from mountains and deserts to glaciers and grasslands. In addition to its mountainous beauty, the Northern Patagonia Icefield is special in that it is the most glaciated terrain on the planet within its latitude of 46.5 to 47.5 degrees south. The region where the ice field lies is a barren sector of South America spanning nearly 3 million square kilometers across southern Argentina and Chile. In the glaciated terrain, thick layers of ice and rock hold a wealth of information regarding global climates of the last 25,000 years, offering a glimpse of where we are headed given the recent anthropogenic (human-caused) acceleration of climate change. The study provided scientists with valuable climate data from the Late Pleistocene and Holocene time periods, which began approximately 125,000 years ago following the final episode of widespread global glaciation. The lead researchers of the study, David Nimick and Daniel McGrath, focused specifically on the the largest outlet glacier draining in the region, the Colonia Glacier on the eastern flank of the ice field. The team sought to constrain the ages of major glacial events by using a variety of dating techniques, including dendrochronology (tree-ring dating), radiocarbon dating, lichenometry (utilizing lichen growth to determine the age of exposed rock) as well as optically stimulated luminescence (dating the last time quartz sediments were exposed to sunlight). Employing such a wide variety of experimental techniques can be a valuable tool in improving the confidence of data and allowed the team to study a diversity of unique properties of the same glacial medium.   By examining properties of lichen and quartz grains (when they were last exposed to sunlight), the research team was able to  constrain the time at which specific rocks were uncovered from the ice sheets. The age at which the ice melted away to reveal these rocks corresponds to events of retreat (and subsequent advance) of glacial ice across the last few millennia. The determination of major glacial events using these techniques sheds light on the climatic events that not only influenced South American paleoclimate but also may affect present and future glacial retreat given the recent spike in atmospheric carbon dioxide levels. Results from dating analyses indicated that the most prominent increase in glaciated terrain occurred 13,200 years ago, 11,000 years ago and 4,960 years ago, with the last major advance defining the onset of Neoglaciation – the period of significant cooling during the Holocene or present day epoch. Analysis of a local ice-dammed lake revealed that glacial growth occurred 2,900 years ago and 810 years ago, with ice retreating during the intervening periods. This data points to the idea that in a general...

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Environmental History of Argentina’s Oldest National Park Unveiled

Posted by on Sep 6, 2016 in All Posts, Featured Posts, Science | 0 comments

Environmental History of Argentina’s Oldest National Park Unveiled

Spread the News:ShareA new study has shed light on the environmental history of Nahuel Huapi, the oldest national park in Argentina. The mountainous glacial region in northern Patagonia is vast, spanning two million acres, yet it has remained relatively unstudied, and little of its ecological history is understood. A study published on August 10 in ScienceDirect has revealed a window into the complex history of glacial Lake Perito Moreno Oeste in Nahuel Huapi, using lake sediments to look back through time. The research team, led by the Argentinian scientist Natalia Williams, investigated the glacial lake’s history by digging deep into the lake’s sediment. Williams and her team hoped to better understand the environmental factors like temperature and human activities influencing the lake’s ecology over the past 700 years, and had the help of a small aquatic species known as Chironomidae. Also known as midges, Chironomidae are a type of insect found on every continent including Antarctica. Across the globe, Chironomidae are abundant and can be used to understand the health and condition of water ecosystems. Unlike other species of their size, Chironomidae leave well-defined remains in lake sediments that allow researchers to study them like fossils. There are over 4,000 distinct Chironomidae species, which thrive in different environment conditions–some prefer warmer water while others prefer cold. By examining the number and species of past Chironomidae, the researchers can understand the health, composition, and temperature of the ecosystem through time. The team collected the proxy data by dropping a 43 cm-long hollow pipe, known as an LL, into the bottom of the lake at Llao-Llao Bay—the deepest point of the lake at 20 meters. When the core was dropped, it filled with sediment and trapped preserved organisms. When the pipe was pulled to shore, it contained the layers of sediment which had built up over time, providing a chronological history of the lake. The researchers were then able to analyze the sediment through photographs, chemical tests, and observations of the sediment and individual midges once they cut the pipe in half. Within the 43 cm-long core, a total of 1594 Chironomidae head remains were identified, and their depth within the core informed the researchers about the time of the deposition, with earlier organisms found deeper in the core. There were higher numbers of warm water species found at the surface layers of the core, representing the more recent history around 1900.  Their high abundance within the core corresponded to a period of time with higher temperatures and increasing human presence in Patagonia. The first buildings within the national park near Lake Perito Moreno were constructed in 1937, and the isolated glacier lake quickly became influenced by pollution, rising temperatures, the introduction of fish species, and the construction of roads. Though the lake was free of human influence until the beginning of the 1900s, the ecology of the lake quickly changed in response to human presence in the park. As roads were built and new species were introduced, the lake’s oxygen levels increased beyond healthy levels and allowed the explosion of the Chironomidae population. When the sediment core showed high levels of the species’ remains, the researchers determined that the lake was less healthy than the period prior to human influence, experiencing an ecological imbalance that prevented other aquatic species from thriving. In order to understand the full extent of human impacts on glacial environments, the history of a region must be taken into account. While it is not possible to go back in time to observe the past, species like those within the Chrionomidae give scientists the chance understand history more deeply.   Spread the...

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