Posts by Sarah Kai Zhen Toh

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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Glacier Loss Threatens Stoneflies in Glacier National Park

Posted by on Dec 13, 2016 in All Posts, Featured Posts, News, Science | 0 comments

Glacier Loss Threatens Stoneflies in Glacier National Park

Spread the News:ShareGlaciers in the Rocky Mountains are undergoing rapid retreat, threatening two remarkable insect species that live in streams fed by glacial meltwater. Lednia tumana (meltwater stonefly) and Zapada glacier (Western glacier stonefly) have recently been proposed for listing under the Endangered Species Act due to the threat that climate change poses to their habitats. A recent study by J. Joseph Giersch et al. published in Global Change Biology offers insight into the factors that influence the distribution of these species, providing valuable information for conservation efforts. In an interview with GlacierHub, Giersch, a scientist at the U.S. Geological Survey (USGS), said, “Findings from our research were used by the U.S. Fish and Wildlife Service (USFWS) to inform the listing decision for the two species.” The study took place in Glacier National Park, Montana, where regional warming has had serious effects. Surveys of glacial extent revealed that 80% of glacial mass within the park has been lost since the 19th century, with full recession predicted over the next two decades, according to Paul Carrara in the Canadian Journal of Earth Sciences. This creates the need for a better understanding of glacier-dependent species such as the stoneflies and ecological implications of species loss. The team of researchers led by Giersch sampled the alpine stream network within Glacier National Park between 1996 and 2015, tracking the abundance of nymph (the immature form and second stage of the life cycle) and adult Lednia tumana and Zapada glacier. Samples of Lednia tumana were found in a total of 113 streams within the park, while Zapada glacier was only detected in 10 streams, six within the park and four within other parts of the Rocky Mountains in Montana and Wyoming. Both species of stonefly are endemic to the region around Glacier National Park and are range-restricted. Their distributions were found to be related to cold stream temperatures and proximity to glaciers or permanent snowfields, with survival “dependent on the unique thermal and hydrologic conditions found only in glacier-fed and snowmelt-driven alpine streams,” according to the study. An interesting feature of both Lednia tumana and Zapada glacier is that they are aquatic in the egg and nymph stages of their life cycles, before becoming terrestrial adults. The adult females lay eggs in short sections of cold alpine streams found directly below glaciers and permanent snowfields within the park. The whole life cycle can last from one to two years. When the stonefly’s eggs hatch, the nymphs swim or drift along the alpine streams, feeding and growing until they emerge as fully grown adults in July or August. The short-lived adults are weak fliers, so they tend to be found on streamside vegetation. Male and female adult Zapada glacier communicate and find each other by drumming (tapping specialized structures in their abdominal segments on the material at the bottom of the stream). After finding each other, they mate and the females lay eggs in the streams, re-starting the life cycle process. Mature Lednia tumana nymphs tend to be about a quarter of an inch-long, while adults are slightly smaller, according to the USFWS. As alpine glaciers in Glacier National Park disappear as a result of climate change, meltwater contributions to alpine streams will decrease, changing the temperature and hydrological regimes that both stonefly species, particularly in the egg and nymph stages, depend on. “The loss of permanent cold water to their native habitat may eventually result in the extinction of these species. Additionally, a shorter-term effect could be a decrease in population connectivity due to cold water dependent species migrating upstream in response to warming temperatures,”...

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Roundup: Volcanoes, Cryoseismology and Hydropower

Posted by on Dec 5, 2016 in All Posts, Featured Posts, Interviews, News, Roundup | 0 comments

Roundup: Volcanoes, Cryoseismology and Hydropower

Spread the News:ShareRoundup: Kamchatka, Cryoseismology and Bhutan   Activity in Kamchatka’s Glacier-Covered Volcanoes From KVERT: “The Kamchatka Volcanic Eruption Response Team (KVERT) monitors 30 active volcanoes of Kamchatka and six active volcanoes of Northern Kuriles [both in Russia]. Not all of these volcanoes had eruptions in historical time; however, they are potentially active and therefore are of concern to aviation... In Russia, KVERT, on behalf of the Institute of Volcanology and Seismology (IVS), is responsible for providing information on volcanic activity to international air navigation services for the airspace users.” Many of these volcanoes are glacier-covered, and the interactions between lava and ice can create dramatic ice plumes. Sheveluch Volcano currently has an orange aviation alert, with possible “ash explosions up to 26,200-32,800 ft (8-10 km) above sea level… Ongoing activity could affect international and low-flying aircraft.” Read more about the volcanic warnings here, or check out GlacierHub’s collection of photos from the eruption of Klyuchevskoy.   New Insights Into Seismic Activity Caused by Glaciers  In Reviews of Geophysics: “New insights into basal motion, iceberg calving, glacier, iceberg, and sea ice dynamics, and precursory signs of unstable glaciers and ice structural changes are being discovered with seismological techniques. These observations offer an invaluable foundation for understanding ongoing environmental changes and for future monitoring of ice bodies worldwide… In this review we discuss seismic sources in the cryosphere as well as research challenges for the near future.” Read more about the study here.   The Future of Hydropower in Bhutan From TheThirdPole.net: An interview with Chhewang Rinzin, the managing director of Bhutan’s Druk Green Power Corporation, reveals the multifaceted challenges involved in hydropower projects in Bhutan. These challenges include the effect of climate change on glaciers: “The glaciers are melting and the snowfall is much less than it was in the 1960s and 70s. That battery that you have in a form of snow and glaciers up there – which melts in the spring months and brings in additional water – will slowly go away…But the good news is that with climate change, many say that the monsoons will be wetter and there will be more discharge,” said Rinzin. Check out the full interview with Chhewang Rinzin here. For more about hydropower in Bhutan, see GlacierHub’s earlier story. Spread the...

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An Earthquake, a Landslide and Two Glaciers in New Zealand

Posted by on Nov 29, 2016 in All Posts, Featured Posts, News, Science | 1 comment

An Earthquake, a Landslide and Two Glaciers in New Zealand

Spread the News:ShareGlaciers can play an important role in landscape dynamics, interacting with other factors to shape landscape development. Two days after a 7.8 magnitude earthquake struck North Canterbury, New Zealand, a landslide occurred between nearby Fox and Franz Josef glaciers. This landslide could offer insight into the role of glaciers in seismically active areas, particularly concerning the ways in which glaciers interact with earthquake-related instabilities in the landscape. The landslide occurred at Omoeroa at around 2 p.m. (GMT +12 hours) on November 16th, closing off a section of State Highway 6 along the west coast of South Island for about three hours until debris were cleared. Due to a slip SH6 is CLOSED btwn Fox Glacier & Franz Josef. Delay your journey. Next update due 6pm. https://t.co/mjVBgtfl9t ^LT pic.twitter.com/n1Vanu1elV — NZTA Canterbury/WC (@NZTACWC) November 16, 2016 Earthquakes and landslides are common in New Zealand due to the country’s location on the Pacific Ring of Fire, the area around the Pacific Ocean that is very seismically active. It is so named because of the prevalence of volcanic activity within the ring, which is made up by the major tectonic plate boundaries. Earthquakes, which occur when Earth’s crust breaks along faults (fractures in the crust), send tremors outwards from the point of breakage. This particular earthquake was caused by oblique-reverse faulting (faulting that had both strike-slip and reverse components) near the boundary of the Pacific and Australian tectonic plates. Landslides, like the one that occurred between the two glaciers, are often triggered by other natural disasters, such as earthquakes or floods. In this case, the earthquake and its aftershocks triggered up to 100,000 landslides, causing local damage and blocking major roads and railway routes. In conversation with GlacierHub, Umesh Haritashya, an associate professor in environmental geology at the University of Dayton, explained that the region in which the landslide occurred is prone to landslides even without any seismic activity. This is due to the topography of New Zealand’s Southern Alps. As such, it would not be surprising if the earthquake, landslide and glaciers are connected, he said. While the two glaciers are found on the west coast of South Island, the earthquake occurred on the east coast of the island. The distance between the two suggests that the intensity of the tremors experienced in the area around the landslide may have been quite low. Nonetheless, a link is possible, according to Jeff Kargel, a geoscientist at the University of Arizona. “The timing of this big landslide is certainly suggestive of a direct link to the earthquake,” Kargel told GlacierHub. “For both direct and circumstantial reasons, earthquakes, glaciers and landslides are closely associated,” Kargel explained. “There is the direct influence of glaciers that produce lots of unstable rock debris over thousands of years, and there are indirect influences, where glaciers erode the mountain topography and produce very steep slopes. These factors create conditions under which seismic activity can easily set off landslides.” In addition, Kargel noted that glaciers occur where uplift rates have been high and the terrain is elevated to begin with. This means that either circumstantially or indirectly, glaciers and landslides can occur nearby. Kargel further stated that large earthquakes tend to create instabilities in the landscape that are later exploited by natural processes, making landslides more frequent in the aftermath of earthquakes. “The spike in landslide activity can last for several years,” he said. In addition to seismic activity, other causes like heavy rain after the earthquake could have contributed to the occurrence of the landslide. New Zealand’s MetService reported that the areas of the glaciers had received considerable...

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Creating the World’s First Ice Core Bank in Antarctica

Posted by on Nov 15, 2016 in All Posts, Featured Posts, Interviews, Science | 0 comments

Creating the World’s First Ice Core Bank in Antarctica

Spread the News:ShareGlaciers contain valuable information about past environments on Earth within the layers of ice that accumulate over hundreds or thousands of years. However, alpine glaciers have lost 50 percent of their mass since 1850, and projections suggest that glaciers below 3500m will not exist by 2100. Concerns about the loss of this valuable resource motivated Jérôme Chappellaz, a senior scientist at France’s National Center for Scientific Research (CNRS), and an international team of glaciologists, to create the world’s first archive of ice cores from different parts of the world. Ice cores are cylindrical sections of ice sheets or glaciers collected by vertical drilling. Chemical components within different layers of ice in glaciers, such as gases, heavy metals, chemical isotopes (forms of the same element with different numbers of neutrons in their nuclei) and acids, allow scientists to study past atmospheric composition and to draw inferences on environmental variables such as temperature changes and sea levels. Cores will be extracted between now and 2020, after which they will be transported for storage to Concordia Station in Antarctica, a joint French-Italian base located on the Antarctic Plateau. Antarctica serves as a natural freezer, allowing the cores to be stored 10 meters below the surface at temperatures of -54°C. International management of the archive, which will be large enough to contain cores from up to 20 glaciers, will be facilitated by the lack of territorial disputes in Antarctica. The first cores that will go into the archive were collected in summer 2016 between August 16th and 27th. Over this time period, two teams of French, Italian and Russian researchers successfully collected three ice cores, each 130 meters long and 92 millimeters in diameter, from France’s Col du Dôme glacier (4300m above sea level) on Mont Blanc, the highest mountain in the Alps. Drilling was carried out within drilling tents at nighttime because daytime temperatures were too high. The cores were then cut into one meter sections for storage and transportation purposes. “The cores are currently stored in our commercial freezers at Grenoble, France, waiting for the long term storage cave at Concordia Station in Antarctica to be built,” Chappellaz told GlacierHub. “One of the three cores will be used during the coming two years to produce reference records of all tracers (chemical components of ice that reveal information about the natural environment) that can be measured with today’s technologies.” The next drilling for the archive will take place in May 2017 at Illimani glacier in the Bolivian Andes (6300m above sea level). As with the drilling at Col du Dôme glacier, the project will be overseen by Patrick Ginot, a research engineer at the Laboratory of Glaciology and Environmental Geophysics (LGGE) in Grenoble. The collection of ice cores has relied on intense international collaboration, and Ginot will be working with glaciologists from Bolivia to extract the cores. Illimani is one of the few Latin American glaciers that contains information stretching back to the last glacial maximum around 20,000 years ago. Although ice cores collected from the Arctic and Antarctica, such as those from Dome C, provide information stretching back to that period, the value of the cores lies in the information they are able to provide about specific regions. For example, ice cores from France’s Col du Dôme glacier can provide information about European industrial emissions, while ice cores from Bolivia’s Illimani glacier could offer insight into the history of biomass burning in the Amazon basin. Glaciers will be selected based on a number of criteria, with priority given to glaciers that contain large amounts of information about the regions from...

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