Historical Data on Black Carbon and Melting Glaciers in Tibet

Black carbon is an atmospheric pollutant. The very small particles are formed through the combustion of fossil fuels, biofuel and biomass, and settle from the air slowly. Also known as soot, this material absorbs solar radiation, trapping heat in the atmosphere and contributing heavily to global warming. A recent study in Atmospheric Chemistry and Physics traces black carbon transport from the Gulf War Kuwait oil fires of January to November 1991 to the atmosphere and ice core at Muztagh Ata Mountain on the remote northern Tibetan plateau. Researchers examine the effects of this material on glacier melt at the plateau, considered the “Water Tower of Asia,” which could impact runoff to the major rivers of Asia.

The beautiful Mugtagh Ata mountain. Muztagh Ata means “ice-mountain father” in Uyghur (Source: Dan Lundberg/Flickr).

Black carbon in the air absorbs and scatters solar radiation, impacting the radiative balance. There is also a more direct affect on the ice, contributing to greater melting. Researchers identified past ice core analyses in the Swiss Alps, Antarctica and Greenland. They recognized the great value of ice cores in providing historical black carbon emissions, distribution and regional aerosol transport. The importance of a historical context in current black carbon deposition guided the methodology for this study. The climate in this region is very sensitive to warming, so any small change in the region’s warming mechanisms could have large impacts on the glaciers and the hydrological cycle.

The black carbon in the ice core at Muztagh Ata Mountain was analyzed along with the atmospheric composition of CO2 percentage at the site. Researchers relied on a chemical transport model used to quantify the global budget of trace gases and aerosol particles, and to study movement by wind in the atmosphere and chemical transformations and removals. They were able to trace different source regions through chemical compositions and measured the temporal variations in black carbon concentration. They also analyzed the long-term trend since the early 1990s of black carbon deposition. Muztagh Ata Mountain is downwind from several source regions: Central Asia, Europe, the Persian Gulf and South Asia. These regions were expected to have the greatest contributions to black carbon accumulation at the mountain site.

Results of the study suggested an unusually strong spike in black carbon during the period from 1991 to 1992. Researchers hypothesized that the massive Kuwait fires at the end of the first Gulf War in 1991 caused this peak in concentration. At the time, Iraqi forces set fire to over 650 oil wells in Kuwait. An estimated 1.5 million barrels of crude oil were released into the environment, making it the largest oil spill in history. Black smoke plumes were monitored by satellites and observed to spread over 2500 kilometers, with some material eventually reaching the Muztagh Ata Mountain.

Camels search for untainted shrubs and water as Kuwait oil fires send large black smoke clouds into the sky (Source: Pier Paolo Antonelli/Flickr).

The chemical transportation model was used to simulate the atmospheric black carbon concentrations and depositions for the period before and after the fires, from 1984 to 1994. The simulation used data for anthropogenic black carbon emissions for the non-Kuwait fire periods and enhanced emissions by 50 times from January to November 1991 to represent the Kuwait fires. Winds by the fire region move in the northern and northwestern direction, and the highest concentration appeared to have been transported westward toward the mountain. This, as well as the historical context, supports the hypothesis that the Kuwait oil fires contributed to greater black carbon on Muztagh Ata.

The high black carbon concentration from this event also had significant effects on the glacier’s snow cover and radiative forcing, which is the balance of incoming solar heat to outgoing heat. Researchers found the radiative forcing increase was about two to five times higher than the normal period before and after the Kuwait oil fires. Also, the black carbon on the upper portion of the glacier would have been covered with fresh snow, but might have stayed longer, uncovered, on the ablation zone. These processes resulted in a significant increase of melting from the glacier since the time of the fires, strongly impacting the hydrologic cycle and water resources in surrounding regions.

Satellite imagery of oil fires spreading westwards (Source: NASA Earth Observatory).

Philip K. Hopke, researcher of environmental chemistry and adjunct professor at the University of Rochester School of Medicine and Dentistry, told GlacierHub about the impacts of black carbon on the Tibetan Plateau. Hopke identifies water supply to be the main issue, considering the glaciers here feed into many major rivers such as the Ganges, Yangtze, and Indus rivers. Loss of glaciers and their water feed could lead to disastrous shortages and conflict over control of resources.

“Enhanced melt by rising temperatures is already an issue and exacerbation by deposited black carbon would make things worse” he added. Hopke also mentions that in some ways, warfare might improve local air quality through reduced economic activity and forced evacuations. Additionally, it would take a major conflict to produce sufficient emissions to have such widespread effects. Fortunately, there are no uncontrolled fires today, though it is important to recognize the risks of war and long-distance impacts. The situation in Syria at present, for example, remains uncertain, as well as the situation in northern Iraq, a country that is home to some of the world’s largest oil reserves, which may be at risk. 

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Epidemics and Population Decline in Greenland’s Inuit Community

The dynamics of climate and environment have a large and growing influence on our culture, practices and health. Climate change is expected to impact communities all over the world, requiring people to adapt to these changes. A recent study by Kirsten Hastrup in the journal Cross-Cultural Research looks at the history of health and environment of the Inuit people of Greenland’s Thule community. Global warming has impacted the hunting economy in the region, and increasing sea contamination is negatively affecting the Arctic ecosystems and human health. Kirsten Hastrup locates these recent changes in the context of earlier dynamics, identifying the social and environmental factors contributing to Inuit development over time.

Effects of Early Exploration and Trade

Colorful houses in the Thule community (Source: Andy Wolff/Flickr).

The Thule community is located in the far northern region of Qaanaaq, Greenland. It is called Avanersuaq, or “Big North,” in the Inuit language of Iñupiat. The Little Ice Age, which lasted from the 14th to 18th century, isolated this small population of 140 from other communities and regions in the south. Waters opened with melting sea-ice in the 19th century, allowing European explorers and whalers to contact the region and the Inuit people. The explorers engaged in trade with the Inuit, exchanging wood, guns, and utensils for fur. Unfortunately, trade and the arrival of whalers introduced new diseases to the community, leading to epidemics and population decline.

Hastrup explains that the Inuit also suffered from famine at the time due to the grip of the Little Ice Age. Expansion of inland ice and glaciers and persistent sea ice made it hard for the Inuit to hunt for food sources like whales, walruses and seals. A lack of driftwood used to make bows, sleds and build kayaks for hunting also contributed to the Inuit’s hardship and further population decline. Natural hazards from living in the Arctic environment led to the decline on a smaller scale. Some of these deaths were due to instabilities of the icy landscape, accidents while traveling across expanses of ice, and large animal attacks during hunting.

Cold War Implications on Health and Identity

Although the risk of disease was great, Hastrup recognizes the impacts of diseases. She also identifies the benefits of trade, which brought resources necessary for hunting and overcoming famine. Development of formal trading stations and greater access to wood allowed for increased hunting capability. Fur trade became quite profitable for the Inuit toward the early 20th century, much to the benefit of the local economy.

However, this did not last long, according to Hastrup. During the Cold War period, the Arctic became a sort of frontier between the U.S. and the Soviet Union. An American airbase was established in the early 1950s, and this had long-lasting effects on health and Inuit identity. Transport vessels, airplanes, and heavy activity at the airbase disturbed the Arctic animals, damaging important Inuit hunting grounds. The population had to relocate to make room for the airbase. This forced movement to new housing sites left a sense of dislocation among the Inuit community.

Fighter aircraft at the Thule Air Base,1955 (Source: United States Air Force/Creative Commons).

A new health risk was introduced in 1959 with the launch of Camp Century, a scientific military camp built under the ice cap. This nuclear-powered camp was also secretly designed to house missiles during the Cold War. The movement of the ice sheet led to an abandonment of the camp in 1966; however, the nuclear threat continued. In 1968, a plane carrying plutonium bombs crashed, going right through the sea ice outside of Thule. Three bombs were retrieved from the waters, although reports in European news media suggest a fourth bomb remains. A nearby fjord was also later revealed to be contaminated by nuclear radiation. According to Hastrup, the people in the region continue to fear risks from radiation-related illness and contaminated food.

Impacts of Changing Climate

These activities and the historical implications of outside contact have left a deep-rooted concern for health and well-being among the Thule community, one that is felt even today. According to Hastrup, many fear that changes in the environment may expose them to further ice-trapped radiation. Camp Century was eventually buried within a glacier, and continued warming is causing movement within the ice. Some Inuit worry that leftover radiation might be released if the glaciers were to retreat, harming the health of their community, Hastrup reports.

Seal meat drying on a platform safe from sled dogs. Qaanaaq, 1998 (Source: Judith Slein/Flickr).

Warming trends impacting the Arctic regions are influencing Inuit practices in certain ways. No longer able to subsist as hunters, for example, the Inuit have adapted to halibut fishing for income. Hastrup argues that in its own way, this adaptation adds a sense of dislocation from tradition. Sharing of game was a longtime tradition among the community, which provided a feeling of unity.

Sherilee L. Harper, associate professor at the Public Health School of the University of Alberta, told GlacierHub about how changing climate might continue to affect the Inuit community. “Research, based on both Inuit knowledge and health sciences, has documented impacts ranging from waterborne and foodborne disease to food security to unintentional injury and death to mental health and wellbeing,” she said.

Despite shifts in traditional practices, Inuit appear ready to meet the challenges of their changing environment. As oceans continue to warm and threaten this Arctic ecosystem, Inuit residents continue to work with governments and climate scientists to monitor changes, deploy conservation efforts, and manage local development. Their openness to change is shown in their shifts to commercial fur collecting in the past to new forms of fishing in the present. Harper added that the Inuit have shown resilience to climate change and continue to be international leaders in climate change adaptation.

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Video of the Week: ‘Claim the Climate’ Protest in Belgium

This week’s video follows the commencement of the UN Climate Change Conference 2018, COP24. This year’s conference is located at Katowice, Poland. The conference, which takes place from 2-14 December, has definitely gotten many people riled up about climate change. Over 65,000 people came out for the “Claim the Climate” demonstration on Sunday, 2 December in Brussels, Belgium. Protestors marched through the Belgium capital toward the European Union headquarters, holding banners saying “Stop Climate Criminals” and “There is no Planet B.” As voiced in the video, they hope to raise awareness on the pressing concerns of climate change and put pressure on political leaders to take action.

Discover more glacier news at GlacierHub:

Are White Whales Resilient to Climate Change?

Then and Now: Understanding John Muir’s Ideology

A Glacial Escape: Connecting Past, Present & Future in the Novel “Antarctica”

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Are White Whales Resilient to Climate Change?

As global warming increases, cold regions like the Arctic continue to experience great shifts in climate and environment. The effects of these shifts are closely observed in human populations, but how are different species impacted? A recent study examined white whales in Svalbard, Norway, and the climate change effects on their behavior and diet. Researchers looked at how reduced sea-ice formation and melting tidal glacier fronts influence the changes in habitat and movement patterns for this species.

White Whale Background and Observations

White whales, also known as beluga whales, can be found in the circumpolar Arctic. They’re known for their distinct white color and are one of the smallest whale species in the world. They are sometimes referred to as “sea canaries” for their high-pitched calls. With an estimated 150,000 individuals globally, they are listed on the IUCN Red List of Threatened Species. Some local populations such as those located in Cook Inlet, Alaska, are considered critically endangered.

White whale spotted in the Arctic and sub-Arctic (Source: Dennis Jarvis/Flickr)

These whales remain off the Svalbard coasts year-round. They live in sea-ice fjords and tidal glacier-front habitats. The fjords are sheltered from open-water predators, human activity, and extreme weather, making them particularly ideal for juvenile mammals. Tidal glacier-fronts are prime foraging areas for the whales. These regions have fresh water ideal for polar cod and capelin, two fish that make up a large part of white whale diet.

White whales migrate seasonally, some travelling 10s of kms, others as far as several hundred. During the warm summer season, sea ice in the fjords melts, providing an opportunity for the whales to move and feed in this region. Sea ice formation in the winter pushes the whales out toward the glacier-front habitats, where they spend most of their time during the colder season.

Methodology and Sampling

Increased warming is expected to negatively influence the environmental composition of this region. Svalbard has the greatest decrease in seasonal sea-ice cover in the circumpolar Arctic region. Rapid increase of air and sea water temperatures over the last two decades are the major contributing factors to this change. According to researchers, glacier-front melting and the associated reduction of foraging habitat could lead to changes in diet. Less sea-ice formation in fjords and warmer seasons could also affect biodiversity in these habitats. Could this mean white whales will need to migrate elsewhere for feeding during warmer seasons?

Researchers in this study compared habitat and movement changes of white whales, before and after major warming induced changes in the environment. They believed these changes began in 2006, so the two study periods were 1995-2001 and 2013-2016.

Fortunately for the researchers, satellite data from earlier years was available. They used satellite tracking to take measurements of whale movement patterns for the later period, and were then able to compare movement patterns for both periods. To track movement, white whale groups were live-captured using a nylon net and then tagged.

Researchers tagging a whale for observation (Source: Kit M. Kovacs)

GlacierHub interviewed Kit M. Kovacs, one of the study’s authors and a senior research scientist at the Norwegian Polar Institute. Kovacs explained that choice of methods reflected concerns for animal welfare as well as data gathering. Groups without calves were netted, to prevent possible injury to young whales, she said. A total of 38 adult individuals were sampled for the study, 34 of them being male. Kovacs also explained that the females travel with their young, while adult males tend to travel in all-male groups, which would explain the sampling bias.

Research Findings and White Whale Resiliency

Results showed that during the later tracking period, the whales continued to remain close to the Svalbard coast. Scientists found this behavior to be striking, particularly when looking at populations in other areas that move long distances. The whales remain close to Spitsbergen, one of the largest islands in Svalbard. They move from the west coast fjords in the summer toward the east coast in the winter. The greatest distance of movement occurred when individuals were forced off the coast by the winter formation of landfast sea ice.

Ice front at a Spitsbergen glacier (Source: Paul/Flickr).

Some changes in habitat were observed. Whales were found to spend much time in glacier-front habitats for both periods, although they now spend more time out in the fjords. Less sea ice formation in the fjords has allowed for an influx of fish species that prefer the warmer waters. Arctic fish, particularly polar cod, have declined in numbers in this habitat, and are being replaced by Atlantic cod, haddock and herring. This new fish composition could be attracting the whales to fjords during the warm season.

Kovacs explained how a change in diet could affect the whales. “White whales use a pretty broad array of food types across their range, so it is unlikely to be a big deal for them to switch to new fish types. They might have to eat more, if the new fishes have a lower fat content, just to keep the same energy intake. As long as enough are available, it should not change their annual intake,” she said.

The white whales’ ability to consume a variety of food resources proves to be beneficial to the species. This helps them build resilience against some of the extreme effects of warming. The beluga may be able to adapt to an environment with less ice than in the past due to this dietary flexibility. Other species may not be so fortunate.

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Photo Friday: Mount Baker from Puget Sound

This week’s Photo Friday features Mount Baker, a glaciated peak in the North Cascades of Washington. Lisa Dilling, a professor of environmental studies at the University of Colorado, Boulder, shared these photos with GlacierHub. They were taken by Dilling during a recent trip to visit family at the San Juan Islands in Puget Sound. These are unusual images, since few glaciated peaks are visible from islands in the ocean. Mount Baker was also a great influence to poet and environmental activist Gary Snyder, who grew up on a dairy farm with views of the peak, and hiked on Mount Baker in his teens.

A beautiful view of Mount Baker (Source: Lisa Dilling).

 

Another view of Mount Baker captured during Dilling’s recent family trip to the San Juan Islands in Puget Sound (Source: Lisa Dilling).

 

Relatively few glaciated peaks are visible from islands in the ocean (Source: Lisa Dilling).

 

Mount Baker peeks out from behind the forest (Source: Lisa Dilling).
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The Future Disappearance of Quelccaya Ice Cap

Quelccaya is the largest tropical ice cap in the world. It is located in the Central Andes of Peru and has a summit elevation of about 5,680 meters. A recent study suggests that the ice cap might soon cease to exist. Researchers used climate data to examine the impacts of the different forcings to determine how imminent its future disappearance is, and to what extent human activity affects the timing.

About 99 percent of the world’s tropical glaciers are located in the Andes, with around 70 percent found in Peru. Glaciers in the tropical Andes are critical to the regional environment. Through runoff, they provide a much-needed water supply during the dry season. A future disappearance of Quelccaya Ice Cap (QIC) could mean significant changes to the ecosystem, impacts on tourism, and consequences to the culture and traditions of the local populations.

Snowy mountain peaks on the Andes mountains in Peru, surrounded by beautiful fluffy clouds.
Andes mountains in Peru (Source: Michael Mcdonough/Flickr).

Scientists used daily air temperature and snow height data to build projections of retreat at the QIC. Air temperature over the Peruvian Andes has increased over the last six decades, leading to greater retreat. Rising air surface temperatures are one of the major contributors to this retreat, although variations in precipitation and snowfall contribute as well. Meanwhile, El Nino and the South American Summer Monsoon can also impact QIC conditions, but on an interannual timescale.

The researchers also examined the different Representative Concentration Pathway scenarios (RCPs) that play a huge role in the future of tropical glaciers. RCPs are used in scientific modeling to provide temporal projections on greenhouse gas concentrations. These concentrations contribute to warming and have a great effect on glaciers. The rate of warming is typically amplified with elevation in many mountain regions due to elevation dependent feedbacks, which are explained further in the study.

Results of the research show that through anthropogenic and natural forcings, QIC loses mass at its front and base. This means that by around 2050, the ice cap could completely disappear. Even with a great reduction in greenhouse gas concentrations, results indicate that an eventual disappearance can be expected closer to the end of the century. The researchers further explained that these findings are consistent with observations of other glaciers in the tropics. We can look at glaciers in Bolivia, Colombia, and Venezuela, as they have also experienced accelerated retreat over the last decades.

Andrew Malone, a Visiting Assistant Professor at The University of Illinois at Chicago (UIC), told GlacierHub more about the shrinking of QIC and its impacts. “The largest impact would be on loss of water resources for communities both locally and downstream. In the short-term accelerated melting actually increases water resources. But as ice melts, that ‘stored’ water shrinks and shrinks, and at some point the glacier reservoir becomes so small that the total run-off contribution starts to decrease with time,” he said.

The melting of Qori Kalis glacier. The left is the glacier in 1978. Right image is from 2011, presenting a retreated glacier and the lake left from melt (Source: Bird Lai/Flickr).

Malone went on to explain that as glaciers melt, lakes form in their place. These lakes are dammed by glacial moraines, which are formed by buildup of falling dirt and rocks from melting glaciers. Moraines are not structurally sound. As ice falls off glaciers and into the new lakes, large waves  can form and flood the downstream landscape. Malone said that this has happened to the lake in Qori Kalis valley, and as a result livestock were lost with the flooding. Similar events can be expected to happen at QIC as well.

While there is much research and understanding of the glacial and environmental impacts of climate change, the human impacts should also be considered. GlacierHub spoke with anthropologist Gustavo Valdivia, who is currently doing research on the Andes. His research looks at the impacts of QIC glacier melt on the nearby community of Phinaya. This community relies on herding alpaca, selling alpaca wool for their livelihood; thus, they are very dependent on runoff waters to irrigate the pastures for their flocks. At present the Phinaya community benefits from the greater runoff, Valdivia said, but this abundance is not likely to last long. The livestock might also be at risk from flooding, as seen in Qori Kalis.

Alpaca from the Phinaya community of Peru (Source: Christian Aid/Flickr).

Valdivia added that there is a key difference between understanding and experiencing climate. Researchers understand the science behind glacial retreat and warming, but it’s the people who experience these changes. He highlighted the importance of building genuine communication with scientific information. As glaciers continue to melt, it’s vital to build connections to the people and communities who are affected, examining ways in which we can adapt to the changes in our climate and environment. Though each community faces climate change in a specific way, they are also part of a global process of change.

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Roundup: Black Carbon, Dying Crustaceans, and Ice Sheet Melting

Kuwait Fires Cause Black Carbon Buildup

From Atmospheric Chemistry and Physics: “Muztagh Ata is located to the east of Pamir and in the north of the Tibetan Plateau. The ice core data provide important information for atmospheric circulation and climate change in Asia. Moreover, the climate in Muztagh Ata is very sensitive to solar warming mechanisms because it has a large snow cover in the region, resulting in important impacts on the hydrological cycle of the continent by enhancing glacier melt.”

Read more about black carbon in northern Tibet here.

Muztagh Ata Mountain, northern Tibetan Plateau (Source: Yunsheng Bai/Flickr)

 

Microscopic Crustaceans at Risk in Patagonian Fjords

From Progress in Oceanography: “Glacial retreat at high latitudes has increased significantly in recent decades associated with global warming. Along Chile’s Patagonian fjords, this has promoted increases in freshwater discharge, vertical stratification, and the input of organic and inorganic particles to fjords.”

Read more about the effects of glacial retreat on Patagonian crustaceans here.

Pia Fjord in Chile (Source: Glenn Seplak/Flickr).

 

Melting Greenland Ice Sheet Contributes to Sea Level Rise

From The Cryosphere: “Mass loss from the Greenland Ice Sheet (GrIS) has accelerated since the early 2000s, compared to the 1970s and 1980s, and could contribute 0.45–0.82m of sea level rise by the end of the 21st century. Recent mass loss has been attributed to both a negative surface mass balance and increased ice discharge from marine-terminating glaciers.”

Read more about the research here.

Massive ice island broken off from Petermann Glacier, one of the 18 glaciers observed in the study (Source: NASA Goddard Space Flight/Flickr).

 

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Horn Signaling at a Medieval Icelandic Monastery

A 16th century ceramic horn fragment was discovered at a former monastery site in Iceland. This object attracted attention as Iceland did not produce ceramics during the Middle Ages. Researchers of a recent study examine archaeological and written records of the region to build an understanding of how this horn traveled to Iceland, and its role in monasticism in medieval times.

Site Details, Findings, and Observations

The ruins of the Skriðuklaustur monastery in eastern Iceland were excavated between 2000 and 2012. The monastery operated for about 60 years from 1493 to 1554. It was abolished as a consequence of the Protestant Reformation, in which religious reform was imposed on the Icelanders. It had at least 13 rooms and a cloister garden. Roughly 300 graves were found at the monastery cemetery. This was a large institution, and traces of human habitation indicate that the monastery was very active.

The monastery excavation plan. The star marks where the horn was found (Source: Mehler et al.).

Skriðuklaustur was also a pilgrimage destination. The monastery was a stopover for pilgrims traveling across the glacier Vatna from southern to northern Iceland. A shift to colder climate led to the growth of glaciers, which covered the route, rendering it unusable. Documents from 1496 reveal that the cemetery was also a burial site for the pilgrims who died along their journeys.

The study indicates that the horn appears to have been relatively small compared to horns found in Germany and Central Europe. Vertical scars on the fragment suggests that the horn consisted of at least two loops, and it shows traces of heavy wear, indicating that it might have been used frequently. Ceramic is also a very fragile material. The user of the horn must have handled it with care for it not to break. These findings suggest that the horn could have held some importance at the church.

Trade and Movement

A chemical analysis of the horn further revealed that the clay came from the Duingen area of northern Germany. This region was an important producer of ceramics during the late Middle Ages and early modern period. Ceramics were very widely distributed as well. These items were transported by ship to Bremen and Hamburg in northern Germany, which were important trading hubs at the time.

Natascha Mehler, one of the authors and a senior researcher at the German Maritime Museum, told GlacierHub about trade and movement of people during this time. She explained that 16th century Iceland was close in trade with merchants from Bremen and Hamburg. “They came to Iceland with their ships each spring, to remain there for the summer in their own trading stations, and in late summer they returned home” she said. Germans mainly conducted business in southwest and west of Iceland, around what is present-day Djúpivogur in Berufjörður. “This fjord is relatively close to the monastery at Skriðuklaustur and the monastery was surely provided with goods from abroad through this fjord,” added Mehler.

European goods were available at three trading stations located near Skriðuklaustur, where people from the region bought and sold their goods. People also traveled to Hamburg in northern Germany from Skriðuklaustur. One example from a historic text describes a sheriff and farm owner travelling to Hamburg via a ship from Hamburg. Some Icelandic clerics were educated at universities in Germany, and they used Hamburg and Bremen ships for their travels.

What Was The Purpose Of The Horn?

The fragment of the ceramic horn found at Skriðuklaustur (Source: Mehler et al.).

The lack of written history makes it difficult to build conclusions on how the horn reached the monastery. Researchers are, however, able to build some possibilities with observations and historical records. One possibility is that the horn was carried by a merchant from one of the trading stations. It is also possible that a traveler acquired it from areas in Germany such as Hamburg and Bremen and brought it back as a souvenir. The third possibility is that a pilgrim carried the horn to the site.

Although there remains uncertainty about how the horn arrived to the site, the use of the horn is better understood. Observations allow researchers to propose that is was used for signaling in the monastery. The length and coarse material would allow only one or two high notes. This limited range suggests that the horn was used for signaling rather than for music. Ceramic horn fragments were also found in German monasteries, and these also appeared to be signaling instruments.

This horn was found in what appears to be the guesthouse area of the monastery site, near the main entrance. Historical sources show that the entrance was once guarded by a man named Jón Jónsson, sacristan to the monastery. Some of his duties were to prepare the church for Mass, and opening and closing the alter screen. The sacristan was also responsible for sounding signals to wake the monks in the morning, and to sound the call to prayer. The horn would’ve been the perfect device for Jónsson to perform these tasks.

The horn that has been silent for centuries has recently come to the world’s attention. Observations and historical records indicate the horn’s use and origin, and gives us a glimpse of monastic life in medieval Iceland.

Vatna Glacier, the largest ice cap in Iceland (Source: Ron Kroetz/Flickr).

Click here to learn more about activities at the Skriðuklaustur monastery and the glacier route!

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Are Melting Glaciers Putting Arctic Fish at Risk?

Shifts in Capelin Fish Feeding Ecology

An important Arctic fish might be in trouble. A recent study in Greenland examines changes in the feeding ecology of capelin, a small forage fish in the smelt family. Melting glaciers are affecting its diet, and this change in diet can heavily influence its growth and reproduction. This could spell trouble for the other animals that eat capelin.

Found in the Arctic, Capelin are an important food source for marine mammals such as whales and seals. Atlantic cod, a major commercial fish species, are one of its major predators. Atlantic puffin also like to feed on them, along with other sea birds.

A puffin enjoying a mouthful of what appears to be capelin (Source: Lawrence OP/Flickr).

Capelin enjoy feeding on plankton, microorganisms that float in the sea and on freshwater. Krill, small shrimp-like crustacean, are also crucial in the diet. Capelin seem to migrate less than other species, making them extremely dependent on the food that’s readily available to them. Any major changes in food availability can ripple through the Arctic food web.

The Godthåbsfjord in West Greenland was sampled at a number of sites, all the way from the mouth where it opens to the ocean to the furthest inland basin. Capelin were sampled by the researchers during the months of May and August, when increased meltwater from summer heating flows into the fjord. The fish were then divided into 2-cm interval size groups, assessing for differences in age. Researchers carefully dissected the stomachs and intestines, preserving them so that they could later examine their contents to determine diets over different locations and times.

Lorenz Meire talks about the framework of the study in an interview with GlacierHub. Meire is a marine scientist at the Royal Netherlands Institute for Science Research and one of the scientists behind this study. “By trawling in a sub-Arctic fjord impacted by glacial meltwater, we aimed to assess the change in capelin size distribution and its diet throughout the season,” he says. Meire adds that scientists tried to link diet with observed changes in zooplankton biomass and environmental conditions.

Three small capelin on tin foil (Source: Rodrigo Sala/Flickr).

What are some observed environmental changes?

Studies show a shift in abundance of krill from freshwater-influenced regions toward the oceans. We see similar shifts with large plankton. GlacierHub spoke with Kristine Engel Arendt, a marine biologist from the University of Copenhagen. Her research on plankton community structure is referenced in the study. She provides some insight on how runoff from the exit glacier and high up ice sheets affect the ecosystem ecology, looking particularly at smaller plankton species.

Arendt told GlacierHub that the fjord typically experiences a bloom of algae in the spring, which is a food source for plankton. The addition of freshwater from the late summer runoff initiates a second bloom of algae, driven by an upwelling of nutrients. “The marine food web is closely linked to the energy source from the algae bloom, and therefore zooplankton species that can utilize food over the entire summer period are favored,” she says. These smaller species of plankton benefit from the nutrients. They use this extra algae bloom during the summer to grow and reproduce. This observation indicates an abundance of smaller plankton at the inner basin region in August. Stomach examinations show a clear increase of small plankton in the diet of fish from this area of the fjord.

Drifting Ice, Godthåbsfjord, West Greenland (Source: Lorenz Meire).

Arendt points out that climate change effects such as melting glaciers are not always negative. We see that this inflow of freshwater is in fact beneficial to these smaller plankton. But how might this change affect capelin?

A Disadvantage to Younger Capelin

It’s important to look at the migration and reproductive pattern of capelin to understand the impacts. Maturing adult capelin spawn from April to June in the fjord, from the inner basin to near-coastal regions. Studies show that all male capelin and some females die off with connection to spawning. Researchers can then presume that the May sample will consist of both mature and immature capelin, and August will be dominated by young capelin. This is reflected in the findings of the study.

The beautiful fjords of Greenland (Source: GlacierHub author Arley Titzler)

The quality of the available food sources must also be examined. It differs with plankton size. Larger plankton species are relatively richer in fat per unit of weight. This makes them more ideal for energy intake and growth than the smaller plankton species. Energy intake and growth is particularly critical for young capelin. Meire told GlacierHub, “If smaller copepods (plankton) become more abundant, they will form a more important food source for capelin. Though this can impact the energy transfer as small copepods in the diet cannot compensate for the absence of larger copepods and krill.”

Lack of the more favored species in the inner regions can negatively affect nutrition of capelin. Younger capelin here are at risk. They will need to feed on the larger, fat-rich plankton to receive enough nutrients to effectively grow and reproduce. This can greatly affect the Arctic food web.

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Video of the Week: Comments from IPCC Chair on SR1.5

This week’s Video of the Week follows the recent release of the IPCC’s special report, SR1.5, on warming impacts of 1.5 degrees Celsius. This short but meaningful video features comments from head of IPCC Hoesung Lee, regarding the observable effects of climate change on societies and ecosystems. SR1.5 urges immediate global response to drastically reduce emissions that contribute to global warming, highlighting the importance of reaching global “net zero” emissions by 2050. The report also suggests strategies for mitigating pathways and transitioning into more sustainable human and environmental systems through adjustments in sectors such as energy, agriculture and infrastructure, to name a few.

Visit the IPCC website for the full report, which includes the Summary for Policymakers and the official press release from Incheon, Republic of Korea. Also, be sure to check out last week’s post on SR1.5 by GlacierHub editor Ben Orlove.

Read more glacier news here:

A Classic Whodunit: Industrial Soot, Volcanoes, and Europe’s Shrinking Glaciers

What An Antarctic Island Tells Us about Mars

Brady Glacier, Alaska Nunatak Expansion and High Snowline 2018

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