North Atlantic Icebergs: Hubris, Disaster, and Safeguards

The view out Diane Davis’ kitchen window on June 23, 2017 (Source: Diane Davis/Newfoundland Iceberg Reports).

2017 marked the fourth consecutive year of “extreme” iceberg conditions in the North Atlantic Ocean. According to the U.S. Coast Guard International Ice Patrol, 1,008 icebergs entered shipping lanes in 2017, almost twice the number in a normal season.

Funded by a treaty of 13 nations, the International Ice Patrol is operated by a U.S. Coast Guard unit, which conducts aerial surveys of the Grand Banks, a region southeast of Newfoundland prone to rough seas and a density of icebergs. Institutions from both the U.S. and Canada comprise the North American Ice Service, which creates a daily iceberg analysis for mariners. The patrol was founded following the sinking of the R.M.S. Titanic in 1912, and, except for the two World Wars, has been in continuous operation since 1913.

Icebergs are created when glaciers calve, releasing pieces of ice to the sea that can be as tall as skyscrapers. Most icebergs in the North Atlantic originate in Greenland, which is rimmed by glaciers that flow to the coast. According to the International Ice Patrol, the elevated count in 2017 was caused by severe storms and higher than normal calving rates of Greenland’s glaciers, which many scientists consider a response to climate change.

However, Mark Carey, an environmental historian at the University of Oregon, says it is overly simplistic to equate iceberg production and climate change, as even growing glaciers calve.

“The classic iconic representation of global climate change is a glacier calving into the ocean, creating icebergs,” he said. “When reports of high numbers of icebergs in the North Atlantic appear, like in the last few years, people might simply think that this is because glaciers in Greenland are shrinking fast and shedding ice.”

An iceberg and oil rig in Bay Bulls on May 1, 2017 (Source: Diane Davis/Newfoundland Iceberg Reports).

In fact, he says the journey an iceberg takes from a Greenland glacier to “Iceberg Alley,” a famously dense area of icebergs on the Grand Banks, is long and complex, and involves more than just glacial calving.

First, a newly-birthed iceberg may never actually leave the fjord in which it was formed. If it does reach the open ocean, it will follow the Labrador Current, which flows north up the west coast of Greenland and south along the east coast of Canada, for as long as two years. During this time, the iceberg may become trapped in sea ice or run aground in shallows. The vast majority of icebergs never reach Iceberg Alley, where the International Ice Patrol counts the icebergs that drift into shipping lanes below 48 degrees north latitude.

“Winter sea ice conditions also affect whether a berg survives and where it goes, so regional weather and not just global climate influence the iceberg journey,” Carey said.

Nevertheless, icebergs can have dangerous outcomes for ships traveling through the North Atlantic region, as the world saw during the sinking of the Titanic and the Danish ship Hans Hedtoft in 1959.

History and global politics makes the North Atlantic especially sensitive to the movements of icebergs. “The North Atlantic has been an integral part of the international political, economic and security system of the day for up to a millennium,” said Rasmus Bertlesen, professor of Northern Studies at the University of Tromsø.

“These shipping lanes are very important, since the U.S., the Canadian East Coast, and Western Europe are power houses of the world economy,” he added.

A life ring that washed ashore in Iceland was the only trace of the Hans Hedtoft recovered (Source: Rasmus Bertelsen).

No ship has collided with an iceberg in the region monitored since the M.S. Hans Hedtoft sank on its maiden voyage. To keep up with fast-moving ice, the Danish Meteorological Institute has recently launched a project that uses artificial intelligence to analyze ice distribution. Though Bertelsen agrees more frequent maps are necessary, he fears history will repeat itself.

“North Atlantic shipping has been the story of technological hubris, human disaster and then technological safeguards,” he said. “Hopefully, these artificial intelligence ice maps will not be the Titanic or Hans Hedtoft of our time leading to disaster and reckoning.”

Carey believes that the portrayal of icebergs as threats to shipping also adds allure to the subject, spurring tourism in places like Newfoundland and Alaska.

Diane Davis, a retired schoolteacher from Newfoundland who runs the Facebook page “Newfoundland Iceberg Reports” agreed.

“Icebergs are a huge tourist draw to Newfoundland and Labrador,” she said.

Davis created the Facebook page to facilitate iceberg sightings in the region. Currently, the page has 7,139 members, who monitor the photographs of icebergs and their locations.

Davis personally witnessed the higher density of icebergs in the North Atlantic over the last four years, and added that many of the icebergs drifted near coastal communities, where people were able to photograph them. The shipping industry is well-practiced at dealing with these icebergs, she said. More concerning to her is the interaction between icebergs and the offshore oil industry.

Diane Davis inspired a character in the Broadway musical “Come from Away,” and met Prime Minister Trudeau when the show toured in Newfoundland (Source: Justin Trudeau/Flickr).

Carey concurs with Davis’ concern. “Icebergs only pose a risk when people get close to the bergs, or when an iceberg drifts close to human populations, infrastructure like docks or drilling platforms, or boats,” he said.

In March 2017, for example, Husky Energy’s SeaRose floating platform came within 463 meters of a large iceberg, threatening 84 crew members and 340,000 barrels of crude oil aboard. The board that monitors industry in the oilfields off Labrador suspended operations for SeaRose, the first such suspension in over a decade.

“Iceberg risk is not just about iceberg production or numbers of bergs in the shipping lanes,” Carey said. “It is also influenced by how often and how many people live, work, travel, and vacation near icebergs–and these numbers are on the rise all the time.”

Of Ice and Fish

Sea ice surrounds this terminal glacier of the Greenland Ice Sheet (Source: Lorenz Meire).

Greenland is a landscape dominated by ice. The Greenland Ice Sheet flows into terminal glaciers, which calve into icebergs, which in winter are locked in by sea ice. Ice shapes the entire food web, from ocean microbes to the fish that fuel 90 percent of Greenland’s GDP.

The relationship between glaciers and Greenlandic fisheries just became clearer with the publication of a recent paper in Global Change Biology. The study found that coastal productivity in Greenlandic fjords is determined by whether the glaciers that flow into the fjords terminate on land, or in the sea.

“Many people think that there aren’t so many things happening in the Arctic,” the paper’s lead author, Lorenz Meire, told GlacierHub. “But during the three of four months of real summer, glaciers melt really fast and the fjords are very dynamic,” he said.

Brash ice before a marine-terminating glacier shows evidence of calving (Source: Lorenz Meire).

Meire and his coauthors compared Young Sound, which receives meltwater only from land-terminating glaciers, and southwest Greenland’s Godthåbsfjord, which is fed by melt from three land-terminating and three marine-terminating glaciers. They found that both were shaped by the glacial inputs, which in summer freshen the surface water and create a stratified water column.

Despite these similarities, the researchers found that Godthåbsfjord was far more productive than Young Sound. In summer, a large “bloom” of phytoplankton grows in Godthåbsfjord, supporting a dynamic food web of krill, other zooplankton, small fish, and migrating animals like whales, seals and halibut. In Young Sound, a small bloom during spring occurs. The fjord is quite unproductive during summer, and the waters cannot support such a diversity of animals.

Bottom-feeding halibut are a mainstay of Greenland’s fishing industry (Source: NOAA).

This difference is due to the upwelling of cold, deep, nutrient-rich seawater that occurs in Godthåbsfjord. Melt enters the fjord underwater at the marine-terminating glaciers. Because it is less dense than the surrounding seawater, the freshwater rises buoyantly to the surface, bringing deep seawater up with it. This seawater delivers nutrients like nitrate, a limiting factor for growth in the ocean, to the phytoplankton who live near the water’s surface.

In contrast, there is no upwelling in Young Sound, and as a result the water is nutrient-poor and 12 times less productive than Godthåbsfjord. Walruses and eider ducks, the top predators in Young Sound, feed on shellfish that live on the bottom.

Greenland’s food web is shaped by glaciers even further. Without knowing which type of glaciers flow into a given fjord, one could guess based solely on the number of fishing boats in the area. Halibut fisherman seek the productive waters fueled by marine-terminating glaciers, but this choice comes with risk. “It’s amazing how the fisherman go fishing in regions that are quite dangerous to sail in, but they keep going because there is a lot of fish,” said Meire. Between changeable weather, cold water, dense icebergs, and sea ice in the winter, many hazards threaten the halibut fisherman, who generally work solo in small dinghies. “It’s much easier in land-terminating fjords because there are no icebergs to destroy your boat,” he added.

Greenlandic halibut fishing dinghies are small and open to the elements (Source: Lorenz Meire).

Even from land, it is clear which fjords are only supplied freshwater by land-terminating glaciers and which are home to marine-terminating glaciers. The fisheries are located close to population centers, and Greenland’s big cities are located next to marine-terminating glaciers, according to Meire. “Almost every spot in Greenland where people live or have lived in the past is close to a marine-terminating glacier. People are aware that these regions are very productive, they understand that the glacier is fueling something,” he said.

As global temperatures rise, more marine-terminating glaciers will melt into land-terminating glaciers (Source: Lorenz Meire).

The question, of course, is what will happen to ecosystems, fisheries and towns as climate change turns Greenland’s marine-terminating glaciers into land-terminating glaciers. “It’s scary to see how fast glaciers are retreating,” said Meire, such as in Godthåbsfjord, where the glaciers have moved back 5-8 km in the last five years. Currently, he added, people in Greenland tend to view global warming as a positive thing, which will make winters easier and provide opportunities for more agriculture. Because the impacts for fisheries are so far in the future, the industry has not yet started to act to mitigate the eventual changes.

“For us, climate change is just a fact,” he said. “Everyone accepts what’s happening. We can make people aware that it will have large consequences on our ecosystem and try to stimulate people to take actions against it.”


Roundup: Glacier News from India, Antarctica, and Kazakhstan

Trekkers Stranded on Indian Glacier

From The Indian Express: “Four trekkers, three from New Delhi and one from West Bengal, who were trying to trek to Kedarnath from Badrinath, have been stranded at an altitude of about 4,000 meters at Panpatia Glacier, which is situated in Rudraprayag district.”

Read more about rescue efforts here.

An Indian Air Force helicopter was dispatched but failed to rescue the trekkers (Source: Arpingstone/Creative Commons).


Pine Island Glacier Calves

From The Washington Post: “The Pine Island Glacier is one of the largest in West Antarctica, a region that is currently Antarctica’s biggest ice loser. Pine Island, which loses an extraordinary 45 billion tons of ice to the ocean each year — equivalent to 1 millimeter of global sea level rise every eight years — is 25 miles wide where its floating front touches the sea, and rests on the seafloor in waters more than a half-mile deep. The single glacier alone contains 1.7 feet of potential global sea level rise and is thought to be in a process of unstable, ongoing retreat.”

Read more about concerns over this ongoing retreat here.

A 2011 NASA image shows a crack 19 miles long in Pine Island Glacier (Source: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team).


Kazakhstan Launches Regional Glaciological Center

From Caspian News: “The activities of the center, which will operate under the auspices of UNESCO, will focus on how climate changes affect glaciers, snow covers, glacial lakes, underground ice, permafrost, and the impact of climate change on regional water resources.”

Read more about plans for the new research station here.

Almaty, the largest city in Kazakhstan, will be home to the new Glaciological Center (Source: Irene2005/Flickr).

Thinking Like a Fish: Navigating Arctic Streamflow Change

This story is Part II of a two-part series on the Tanana River Watershed. See Part I here.

Melt from Alaska Range glaciers feeds lowland rivers through the year (Source: Salcha-Delta Soil and Water Conservation District).

Long-term monitoring has consistently shown that winter flow levels in Interior Alaska rivers are rising. But why? Precipitation is not systematically increasing, and most source waters are frozen in winter. According to a new paper in Geophysical Research Letters, the answer comes from far away: as mountain glaciers melt during the summer, melt water percolates into aquifers and later resurfaces downstream, making streams flow fuller in the coldest months.

For University of Alaska Fairbanks researcher Anna Lilijedahl and her coauthors, arriving at this conclusion meant uniting two different disciplines. “I came to realize by talking to colleagues and friends and reading papers that in the Arctic, the glaciology and hydrology communities are often doing the same things in parallel,” Lilijedahl told GlacierHub. “I saw an opportunity to link the two—what happens when water leaves a glacier and travels hundreds of miles to the ocean?” she wondered.

A map shows the relationships between the study areas (Source: Lilijedahl et al, 2017/Geophysical Research Letters).

As her study area, Lilijedahl chose the Jarvis Creek watershed, which she called “accessible by Alaska standards,” meaning it runs parallel to the Richardson Highway and can be reached without a helicopter. The discontinuous permafrost that underlies this basin is characteristic of Interior Alaska, and Lilijedahl considers the region a proxy of other glaciated watersheds north of the Alaska range that lack road access.

To examine the relationship between glaciers, permafrost, and streams, Lilijedahl took a trip back to an older, colder time in Interior Alaska. She examined the Tanana River winter discharge record, which began in Fairbanks in the 1970s. It shows a steady increase in wintertime flow, as do similar records of streams across the Arctic and subarctic. She also analyzed satellite data and found that glacier coverage in the Tanana River watershed (of which Jarvis Creek is part) decreased by a remarkable 12 percent between 1950 and 2010.

Armed with this historical data, Lilijedahl and her team turned toward the present conditions of Jarvis Glacier and the Tanana River watershed. Scientists from the U.S. Geological Survey (USGS), the Army’s Cold Regions Research and Engineering Laboratory, and the Salcha-Delta Soil and Water Conservation District worked together to measure how much ice and snow Jarvis Glacier lost over the summer. They placed two gauges in the outflow stream, 55 kilometers apart.

Lilijedahl’s team deployed instruments in spring to determine how much ice melted over the summer (Source: Salcha-Delta Soil and Water Conservation District).

“This is the only study that I’m aware of that put two stream gauges in front of a glacier,” USGS glaciologist Shad O’Neel told GlacierHub. This innovative method yielded interesting results: the stream lost roughly 46 percent of discharge between gauges. Such staggering loss is probably happening globally, according to O’Neel. “Around the world, glaciers turn into braided rivers with an abundance of sand and gravel that’s particularly good at soaking up water,” he said.

The scientists don’t yet know how long this water remains in the aquifer, but it clearly stays at depth long enough to be warmed by the tectonically active ground that underlies the Alaska Range. The 6 degree Celsius temperature of the groundwater is an “indicator that water has traveled pretty deep before coming back up. The deeper you go into earth, the warmer it gets,” said Lilijedahl.

From the aquifer, the water leaks into Jarvis Creek through the winter. “Everything is frozen except groundwater, so that’s definitely the source,” added O’Neel.

As glacial melt increases, the water melts the surrounding permafrost, enlarging the aquifer. Though this means that storage capacity is higher, input will ultimately decrease as the watershed’s glaciers shrink in a warming climate. Eventually, local wells may run dry, and Lilijedahl believes that lowland areas of Jarvis Creek and other similar rivers could eventually go dry in the summer.

The Richardson Highway, seen here just north of Delta Junction, parallels the Jarvis Creek watershed (Source: Rachel Kaplan).

Drying streams would threaten an animal important to Alaskan culture and economy—salmon. According to the Alaska Seafood Marketing Group, “Salmon are responsible for the greatest economic impact (jobs, income, and total value) among all species in the Alaska seafood industry.” In 2013 and 2014, this industry generated an average of 5.9 million dollars of total economic activity. Salmon is also a crucial resource for people living subsistence lifestyles. “A lot of Arctic communities rely on chum salmon for food and pet food. Some species may do well, others won’t fare so well,” said O’Neel.

The health of salmon populations depends on a complex web of factors, including water temperatures in areas where eggs develop and stream levels where adult salmon migrate. Glacial melt and groundwater reserves shape both factors. Chum salmon eggs develop faster where warm water, between 3 and 6 degrees Celsius, bleeds into rivers. Salmon lay their eggs where the 6 degree Celsius groundwater upwells in the Tanana and Yukon rivers, according to Lilijedahl.

Glacial contributions to streamflow can also help support adult salmon. Glacial melt accounted for over 15 percent of Jarvis Creek’s annual discharge. For streams in the Alaska Range that aren’t glacially fed, said Lilijedahl, flow near mountains may yield to dry river beds a few miles downstream. “Imagine that if you’re a fish!” she said.

Salmon, such as the Sockeyes shown migrating here, are essential to Alaska’s economy and culture (Source: S. Huffman/NPS).

Thinking like a fish is key to many scientists and decision-makers in Alaska. The ancient migration habits of salmon have for millennia guided them between the ocean and their freshwater birthplaces, where they spawn before dying. Favorable conditions, such as water temperature and sufficient stream flow, constitute the difference between life and death, a poor year for Alaskan fisheries and a booming one.

The findings from this study will help in management of salmon populations. It will also help with understanding the impacts of climate change on a much broader scale. “In the past, we assumed all loss from glaciers ended up in ocean. But hey, wait—at least 30 percent in this system is lost in the aquifer. It introduces more complexities into this sea-level rise thing,” said O’Neel.

Faced with the complexities of a changing climate, myriad impacts of which are already shaping Arctic and subarctic landscapes, further collaborations between the hydrology and glaciology communities will be essential. “We’ve drawn a linkage between the physical systems of glaciers and the biological system of salmon. No one would have guessed that existed, not that long ago,” said O’Neel.

Photo Friday: Island Glaciers of the Canadian Arctic

Outside of Greenland, a quarter of the Arctic’s ice lies in Canada, much of it covering the Queen Elizabeth Islands. A recent paper in Environmental Research Letters found that, during the decade between 2005 and 2015, surface melt from the ice caps and glaciers of the Queen Elizabeth Islands increased by a staggering 900 percent, from an annual average of 3 gigatons to 30 gigatons of water.

This vast input to the ocean renders the Canadian Arctic a major contributor to sea level rise. As the Arctic continues to warm, researchers expect the glacial melt to increase significantly in the next decades. While the glaciers of the Canadian Arctic remain, take a look at some striking NASA imagery of the glaciated Queen Elizabeth Islands.

A MODIS satellite image shows the icy Queen Elizabeth Islands and Baffin Island (Source: NASA).


Ellesmere Island has been inhabited since about 2000 B.C., and its current population is less than 200 (Source: NASA).


Retreating glaciers provide melt water to Ellesmere Island’s Oobloyah Valley during the summer. A willow and primrose species have been found in the moraine of the Arklio Glacier (Source: NASA).


About a third covered by a large ice cap, Devon is the largest uninhabited island in the world (Source: NASA).


A NASA Operation IceBridge flight captured a picture of Belcher Glacier, which flows from the Devon ice cap to the ocean (Source: NASA/Twitter).


Lessons in Collaboration from the Tanana Watershed

This story is Part I of a two-part series on the Tanana River Watershed. See Part II here.

The Tanana River flows toward Delta Junction, with the Alaska Range in the background (Source: Rachel Kaplan).

What do a St. Patty’s Day party and a sub-Arctic river have in common? An abundance of green dye, which acts as a festive element for the first and a scientific tool for the second.

A group of Alaskan scientists used this green dye as a tracer in studying the intersection of glaciology and hydrology in subarctic rivers, and recently published their findings in Geophysical Research Letters. They found that glacial meltwater interacts with rivers and groundwater across the landscape in complex ways, which has implications for the life the landscape supports—including humans.

I spoke with the study’s lead scientist, Anna Lilijedahl, over Skype at opposite ends of our days. Anna, who was attending a conference in Oxford, sat on her hotel room bed in a sweatshirt that read “Yukon River Camp,” and I huddled in a sweater at my desk in Fairbanks, Alaska, listening as she talked to me about the sub-arctic Interior Alaska landscape I grew up in.

Small rivers are difficult to sample in winter, she told me, because of the thickness of the ice build-up. “Little channels of water run through it like a spider web, you can hear it in the ice if you listen,” she said.

From listening to wintertime trickles to trekking across glaciers, Lilijedahl and her team have engaged intensely with the Tanana River watershed, a major tributary of the Yukon River. Internationally important to subsistence lifestyles, remote northern travel, and commercial salmon fisheries, the river flows over 2,000 miles through Alaska and Canada before draining into the Bering Sea.

The glacial headwaters of Jarvis Creek are in the Alaska Range (Source: Salcha-Delta Soil and Water Conservation District).

Lilijedahl’s study involved extensive surveys on Jarvis Glacier, snow machine travel in the mountains, and probing frozen rivers to gauge their flow. What I noticed the most about Lilijedahl during our conversation was how she uses hydrology to bring people closer to their landscape, and to one another.

“We’re really excited about her work because it has a big impact not only on our community, but also for the agency,” said Jeff Durham, program director of Salcha-Delta Soil and Water Conservation District, a state agency that works with local landowners and government agencies to manage natural resources in nearly four million acres of Interior Alaska. The project constituted a collaboration between the University of Alaska Fairbanks, where Lilijedahl is based, the Salcha-Delta Soil and Water Conservation District, which provided logistical and backcountry support, and researchers from both the U.S. Geological Survey and a research branch of the U.S. Army.

According to Durham, this collaboration has drawn both attention and funding to the project. One proposal reviewer from the National Science Foundation wrote a letter naming this partnership as a hallmark of the scientific process, emphasizing that scientists should work with local agencies, not just live in the halls of academia. “It’s a great opportunity for us to jump in with her and get a lot of information. We can look forward toward what will happen with the water table and our community,” Durham said.

Delta Junction lies at the end of the Alaska Highway, one of the major arteries linking the U.S. and Canada (Source: Author Nader Moussa/Creative Commons).

As he drove through Interior Alaska, Durham talked to me by phone about what he calls the “boom and bust town” of Delta Junction, a small community near Jarvis Creek where you can leave a chainsaw in the back of your truck at the grocery store and it won’t be stolen. As Jarvis Glacier continues to melt, and eventually disappear, Delta Junction’s aquifer may dry up. When this happens, wells, which are a major resource in an area without municipal water, will run dry. According to Lilijedahl, the watershed’s glaciers are so diminished that the amount of water in aquifer storage is already decreasing.

Lilijedahl gave a presentation about her research findings in Delta Junction, surprising its residents with the importance of far-away Jarvis Glacier to the aquifer. Lack of understanding about the connection between mountain glaciers and lowland water resources is common, says Lilijedahl. Her paper in Geophysical Research Letters concludes that “high-latitude mountain glaciers represent an overlooked source to subarctic river discharge and aquifer recharge.” She calls the Jarvis Creek watershed a “proxy watershed” and believes the relationship between glacial melt and aquifer recharge exposed by her research will hold true for other subarctic regions in Alaska, Canada, and beyond.

“The fact that she’s worked so closely with a local natural resource agency, shared information, made an effort to come into the community—that’s the key in what Anna’s doing,” said Durham. “She brings complicated information into our community and makes it palatable. It’s easy to have those conversations in the halls of academia. Having them with someone who doesn’t have the background is the real challenge.”

Colin Barnard probes the snow in Jarvis Canyon (Source: Salcha-Delta Soil and Water Conservation District).

With regards to Jarvis Glacier and Delta Junction’s water resources, the future is coming. When will the water levels drop? In Durham’s lifetime or his children’s? As water pours from Jarvis Glacier into the aquifer, it melts the permafrost and carves the aquifer deeper, increasing water storage capacity and releasing carbon stored in the permafrost. This process raises a host of future research questions for Lilijedahl. “How much permafrost have we really thawed because of this increase in glacial melt?” she wonders. “This melt brings old carbon stored for thousands and thousands of years into the river, and in contact with bacteria.” Typically, attention is focused on glacial melt’s contribution to sea level rise, she says, but there are several directions in which to explore the impact on the terrestrial ecosystem.

Alaska is ground zero for climate change, according to Durham. “It’s obvious that the Jarvis is drying, we can see that from a visual standpoint. It’s a canary in a coal mine, and that’s why this work is so important,” he said. He expects the state to see impacts from temperature rise before other places. “How will we build, and how will we deal with what has been built?” he wonders.

Lead scientist Anna Lilijedahl during winter field research (Source: Salcha-Delta Soil and Water Conservation District).

Melting permafrost has impacts all over Alaska, Durham says. Roads undulate, the ground becomes unstable, and the ultimate consequences for towns and infrastructure are still unknown. One consequence for Delta Junction’s infrastructure may actually be positive: stable through the year, Jarvis Creek discharge has a temperature of 6°C, the signature temperature of aquifer water in the watershed. Though it sounds chilly, this is actually warm, especially relative to winter temperatures in the region. Lilijedahl thinks that people in Delta Junction could use the water as heat source to warm their homes.

With major changes to life imminent in Delta Junction and other places in Alaska, partnerships between scientists and local agencies will lead the way in research and future mitigation efforts. As the landscape changes, the only choice is to draw closer to it, and to one another.

Life, Death and Predation on the Greenland Ice Sheet

The Greenland Ice Sheet is the world’s second-largest body of ice (Source: Krzysztof Zawierucha).
Mention the Greenland Ice Sheet, and chances are that you conjure up the image of a barren, white wilderness, dominated by ice and devoid of life. In fact, the ice sheet and its coastal outlet glaciers support thousands of small pools that teem with bacteria and animals. “A world of microbes exists in these tiny, frozen, cold pools on glaciers. There’s life, death, and predation happening,” marveled glaciologist Aurora Roth.

These little pools are called cryoconite holes, pockets in the surface of glaciers that are usually ovular or circular. Cryoconite holes can be quite small and shallow, or as wide as a meter and up to half as deep. “People first notice cryoconites because they look so odd, like honeycomb. The textures are visually striking,” says Roth. She added that they constitute such an extreme environment that scientists look to them to understand the evolution of simple life forms on Mars and other planetary bodies. A recent paper in Limnology by Krzysztof Zawierucha et al. analyzed cryoconite communities on the margin of the Greenland Ice Sheet and found that the distribution of microfauna at the edge of the sheet is random, without clear ecological determinants like water chemistry or nutrient availability.

Sediment lies at the bottom of cryoconite holes of various sizes (Source: Krzysztof Zawierucha).
Cryoconite holes (and their larger versions, puddles and lakes) are full of water, and contain debris deposited by wind, rockfall or water flow. Small debris particles can be bound together by cyanobacteria into granules, which eventually erode into mud. Both granules and mud foster communities of bacteria and animals that comprise the biotic hotspots of the ice sheet. Microorganisms are the top consumers in cryoconite food chains, a position impossible for them to occupy in most other ecosystems, where they are eaten by larger organisms. Such unusual dynamics make “this icy world more and more fascinating,” Zawierucha told GlacierHub. “Despite the fact that they are in microscopic size, they are apex consumers on the glacier surface, so they are like polar bears in the Arctic or wolves in forests,” he said.

Zawierucha conducted his fieldwork at the beginning of polar autumn and was struck by the changing colors of the tundra, the musk oxen and the impressiveness of the ice sheet, which together created a landscape that felt right out of a fairy tale. As he trekked through wind and rain to collect samples from cryoconite holes, puddles and lakes, he often felt as if he was in a science fiction movie about “icy worlds in other galaxies.”

Zawierucha poses against the dramatic landscape of the ice sheet during fieldwork (Source: Krzysztof Zawierucha).
Back in the lab, Zawierucha found rotifers and tardigrades swimming around in his samples, two hardy invertebrate groups that also live in freshwater, mosses, and for the tardigrade, extreme environments–tardigrades are the only animals that can survive outer space. The invertebrates were far more common in granules than mud. The paper suggests two reasons for this disparity: the mechanical flushing action of water that forms the mud and the food source the granules provide for the invertebrates. The samples boomed with other types of life, as well: they contained thirteen types of algae and cyanobacteria, plus different groups of heterotrophic bacteria.

The flushing process, and the way it affects the animals which it displaces, raises many questions for Zawierucha. How much wind or rain is required to remove the animals from the cryoconites? “How many of them are flushed to downstream ecosystems, and how many stay in the weathering crust on glaciers?” he wonders. And what happens once the animals are out of their holes? Zawierucha harbors what he calls a “small dream,” to find active animals in the subglacial zone (the hydraulic systems under a glacier). “If they are flushed to the icy wells, are they able to survive under ice?” he asks.

Tardigrades are found on all seven continents, in a range of extreme environments (Source: E. Schokraie et al./Wikimedia).
In the future, Zawierucha would like to continue to close what he calls the “huge knowledge gap” between the vast amount of research devoted to microbial ecology on glaciers and the dearth of information about animals. “Even if their distribution is random, they still may play an important ecological role in grazing on other organisms,” he believes.

Tardigrades, some species of which are black in color, may have an even bigger effect on glacial dynamics and global climate. Tiny though they are, populations of black tardigrades in cryoconite holes, which Zawierucha has found on alpine glaciers, can reduce albedo and increase melting of the glacier surface. This may constitute a positive feedback loop that hastens glacial melting, but more studies are required to prove this, Zawierucha says.

One positive feedback loop is clear. Higher temperatures increase the melting of glacier surfaces and spur microbial activity, which in turn speeds up the process of melting, according to Zawierucha. As the Greenland Ice Sheet continues to melt, the animals that call it home will be disturbed, though it is difficult to anticipate the end result. How tardigrades, especially species unique to glacial habitats, will respond to higher flushing rates and removal from glaciers is of particular interest. Perhaps the tardigrades will adapt, or perhaps they will go extinct, says Zawierucha.

Zawierucha prepares samples for transport off the ice sheet (Source: Krzysztof Zawierucha).
Faced with an uncertain future, glaciology projects that cross disciplines make Roth hopeful. “It’s a good example of what happens when you look at a system through an interdisciplinary lens,” she told GlacierHub. “When you bring in a biologist, you see the difference in the questions they ask and things they unearth.”

Now is the time for such interdisciplinary research: more studies of animals living on the Greenland Ice Sheet will help scientists understand how this important freshwater reservoir, and Earth’s climate, will respond to global warming.

Roundup: Dust, Collapse, and Fire

Dust Distribution in East Asia

From Journal of Meteorological Research: “East Asian dust (EAD) exerts considerable impacts on the energy balance and climate/climate change of the earth system through its influence on solar and terrestrial radiation, cloud properties, and precipitation efficiency. Providing an accurate description of the life cycle and climate effects of EAD is therefore critical to better understanding of climate change and socioeconomic development in East Asia and even worldwide.”

Read more about how dust increases glacial melt here.

A schematic representation of how dust shapes precipitation patterns in Asia and Africa (Source: Journal of Meteorological Research).


Swiss Glacier Collapses

From The Washington Post: “Part of a glacier in the Swiss Alps has broken off and tumbled onto a glacier below after some 220 people in a small nearby town were evacuated as a precaution. Authorities ordered a partial evacuation of Saas-Grund on Saturday after radar surveillance of the Trift glacier, above the southern town, showed the glacier’s snout moving at a rate of up to 130 centimeters (51 inches) per day.”

Read more about the Trift Glacier avalanche here.

The town of Saas-Grund was evacuated in anticipation of an avalanche on nearby Trift Glacier (Source: Wandervogel/Wikimedia).


Glacier National Park Landmark Burns

From NPR: ” The Sperry Chalet was one of a handful lodges built in the early 1900s by the Great Northern Railway. The Swiss-themed complexes were spaced about a day’s horseback ride apart. Before the Sperry Chalet burned, it and the Granite Park Chalet were the only two left standing. Sperry’s two-story dormitory is considered a complete loss, but the nearby kitchen and dining room may be salvageable. That potential silver lining has social media buzzing with memories of the roasts, pies, fresh coffee and crispy bacon served daily by the chalet’s dedicated kitchen staff.”

Read more about this casualty of the Sprague Fire here.

Sperry Lodge is listed on the National Register of Historic Places (Source: National Park Service/Wikimedia).

Future Unwritten: Antarctic Sea Pens’ Secrets to Success

A sponge, Haliclonissa verrucosa, filter feeds in water off of Spume Island (Source: Chuck Amsler).

On the seafloor, beneath the cold, dark waters surrounding Antarctica, life blooms. Sea stars make their glacially-slow journeys along rocks, sponges rhythmically pulse water through their internal cavities, and one particular coral, the delicate sea pen Malacobelemnon daytoni, flourishes.

Sea pens are colonial, meaning that many individuals work together as a whole, each conducting a specialized task necessary for survival. The resulting shape resembles a quill pen, earning them their creative common name.

M. daytoni is one of the most abundant species in Potter Cove, located off the southwest side of King George Island in the South Shetland Islands. The environment of Potter Cove is heavily influenced by local glacial retreat, which discharges increasing quantities of sediment into the ocean. Researchers know little about benthic (defined as the lowest layer in a body of water) ecology in this region, challenging as it is to conduct scientific research in the cove’s remote, frigid waters. A recent paper in Marine Environmental Research by an international team from the Universidad Nacional de Córdoba and Institute of Marine Science analyzed the biochemistry of M. daytoni to understand its ecological success. They found that the key is a flexible, omnivorous diet and strategic reproductive techniques.

A sea pen in Potter Cove (Source: Ricardo Sahade).

Natalia Servetto, lead author on the study, is part of a group that has been studying the Potter Cove benthos since 1994, thanks to logistic support of the Instituto Antártico Argentina, the Alfred Wegener Institute and the National Scientific and Technical Research Council (CONICET). These efforts have revealed what Servetto called an “unexpected and marked shift in the system… linked to ongoing climate change processes” and to glacial retreat, which has increased sedimentation rates, affecting the benthic fauna. In the last few years, Servetto says, the abundance and distribution of M. daytoni has increased significantly, while many other Potter Cove invertebrates are becoming less abundant.

Why should the sea pen thrive while its neighbors perish? To answer this question, a team based out of the Argentine Carlini Station scuba dove every month for one year, sometimes through holes in the sea ice, to depths of 15 meters to take tissue samples from sea pens in Potter Cove.

This in itself is a feat. Chuck Amsler, a biology professor at University of Alabama at Birmingham who studies macroalgae and invertebrates in the Western Antarctic Peninsula, told GlacierHub that diving to study Antarctic life is a challenge because, “It’s damn cold!” However, Amsler added, “The scientific reward is that you have the opportunity to observe your study system directly. There is no substitute for the kind of insights one can get from that.”

Carlini Station provides access to the remote Potter Cove (Source: Natalia Servetto).

Many such insights came to fruition back in the lab, where the researchers analyzed the carbohydrate content, stable isotope ratios, and fatty acids in the coral tissues, looking for chemical clues to what the pens eat through the year. Just as a savvy New Englander might buy groceries with the seasons, eating peaches in summer, apples in autumn, root vegetables in winter, and fresh maple syrup in spring, the researchers found that the sea pen’s diet changes seasonally. In summer, M. daytoni feasts on copepods (a type of small invertebrate), phytoplankton, and a bit of macroalgae detritus. In autumn, the menu features more phytoplankton and microalgae, and in winter, macroalgae detritus and sediment are the sea pens’ bread and butter. In spring, their diet becomes fresher again when phytoplankton and microplankton return to the table.

This omnivorous, opportunistic feeding strategy allows the sea pens to eat whatever is available in a given season, reducing pressure on the species during times of food depletion. Such depletion peaks in winter and autumn, forcing M. daytoni to scavenge for organic sediment and detritus that become re-suspended from the seafloor. Sea pens have another major advantage over their neighbors: inorganic sediment from melting glaciers can clog the respiration and feeding mechanisms of filter-feeding invertebrates, while M. daytoni continues to chow down, undisturbed.

Amsler and his team begin a dive to study benthic macroalgae and invertebrates (Source: Maggie Amsler/Antarctic Photo Library).

Not only do they feed resourcefully, but the sea pens also optimize the energy they obtain. Servetto’s team found that lipid content in their tissues, associated with reproduction, increased in rapid bursts that were seasonally linked with higher food availability. This pattern suggests that sea pens can take the energetic resources offered by the environment at a given time and shunt them into reproduction, the most important process for any organism.

Beyond any single year, and beyond the bounds of the Potter Cove ecosystem, the opportunistic feeding and reproductive strategies of M. daytoni will help this species thrive. Nearly 90 percent of glaciers are retreating along the Antarctic Peninsula, causing environmental shifts that threaten many species, but could create an opportunity for sea pens to actually expand their range, Servetto says. As glacial retreat creates new ice-free areas, colonization may occur, according to Servetto, “at a previously unimagined speed.”

However, it’s not yet clear how the Antarctic coastal system will evolve as glaciers melt. Amsler says that decreasing sea ice cover will likely favor macroalgae and their associated communities of small, mobile invertebrates like amphipods and gastropods, and threaten shallow-water sessile invertebrates like the sea pens, probably pushing them into deeper water. Decrease in sea ice cover may also have broader climate impacts: the Antarctic benthos is a net carbon sink (a natural process that stores carbon), and as ice cover decreases, Amsler expects that benthic primary production will increase, removing even more carbon from the atmosphere.

Divers in Antarctica face difficult conditions, including brash ice (Source: Chuck Amsler).

No matter the outcome, the impacts of climate change on benthic Antarctic invertebrates will be manifold. Other forces, like ocean warming and acidification, will also affect M. daytoni and reshape benthic invertebrate communities, though Amsler says more work is needed to understand how. “I don’t know what the community will look like in 100 years, but I’m confident that it will be different from what we see today,” he predicted. As climate changes and glaciers melt, the flexible diet and efficient reproductive strategy of M. daytoni will give it an advantage in changing Antarctic coastal ecosystems.

Photo Friday: Monitoring Chile’s Volcanoes

Currently, three volcanoes in Chile are restless, according to the Servicio Nacional de Geología y Minería. A “class yellow” status for these glacier-covered peaks means elevated seismic activity and higher potential for eruption.

The ice caps on these giants mean that an eruption could spur Jökulhlaups, glacial outburst floods that can be extremely dangerous, such as in the 2010 eruption of Iceland’s Eyjafjallajokull.

Will all three Chilean volcanoes erupt, or none? Which will erupt first? Monitor the situation from home by watching their webcams.


Planchón Peteroa, located in central Chile, last had a major eruption in 1991 (Source: SERNAGEOMIN).


Landsat imagery reveals the complex topography of Planchón Peteroa’s caldera and slopes (Source: SERNAGEOMIN).


Ranked as the ninth-most dangerous volcano in Chile, Copahue was snow-covered and peaceful on August 31, 2017 (Source: SERNAGEOMIN).


Nevados de Chillán, the seventh most dangerous volcano in Chile, had notable seismic activity in 2016 (Source: SERNAGEOMIN).


Villarrica, ranked by SERNAGEOMIN as the most dangerous volcano in Chile, last had a major eruption in March 2015. Villarrica is not currently active (Source: SERNAGEOMIN).


Driving the Dalton: A Tour of North Slope Glacial History

The Dalton Highway and surrounding landscape are icy in March (Source: Emma Boone).

The only road in the United States that crosses the Arctic Circle is the Dalton Highway: a remote, potholed, perilous path that begins north of Fairbanks and terminates at the Arctic Ocean. For some, driving the Dalton is a bold, lonely adventure, and for others, it’s just a long commute to work. Molly Timm, field operations assistant at University of Alaska’s Toolik Field Station, has driven the Dalton over ninety times. “It’s nicer in winter because there are fewer potholes,” she told GlacierHub.

No matter what brings you to the bumps and beauty of the Dalton, driving the young “Haul Road,” built in 1974, is a journey through time. The North Slope landscape is filled with features that date back to a series of glaciations beginning 2.6 million years ago. If you decide to stretch your legs, any given hike in the Brooks Range will likely involve scrambling over moraine rocks, and navigating the hill-sized heaps of gravel called kames that dot the tundra. Easier stretches will have you striding over the rolling heath, its crests and troughs the result of depression by glacial ice.

About a quarter of the Dalton Highway, such as this section looking north to Sukakpak Mountain, is paved (Source: Henry Masters).

“Really, the entire Arctic landscape is shaped by glacial activity, past and present,” Ruby An, terrestrial research assistant at Toolik Field Station, reflected on the North Slope. “If you look at Google Maps, you see a spiderweb of lakes all along the coastline.” In fact, some regions of the coastal plain consist of lakes and ponds formed on top of old, drained lakes, a sign of the permafrost layer that belies the tundra.

My drive up the Dalton begins, like all others, in Fairbanks. I am headed north with two other scientists to study kettle ponds, formed when glaciers dropped large chunks of ice as they receded. Dan, Kyle, and I spend our first morning together running around Interior Alaska’s largest city (population 33,188), loading the truck with scientific equipment, spare tires, beer, gasoline, water and food.

Musk oxen first colonized Alaska during the Pleistocene (Source: Henry Masters).

During the last glacial maximum, about 20,000 years ago, Interior Alaska was an ice-free grassland inhabited by animals like steppe bison, American lions, and giant short-faced bears. The Fairbanks area today is characterized by boreal forest and granite tors, large rock formations that persist as testaments to the lack of local glaciation.

The Dalton starts slow. I doze in the back as Kyle drives our heavily-provisioned truck through the birch-covered slopes outside of Fairbanks, which slowly yield to a spruce forest, scraggly and crooked on the frozen loess, a silty clay layer that covers much of Interior Alaska. North of Coldfoot, a town with a gas station, diner, and population of 11, everything changes. The trees disappear, granting us clear views of hills that grow as we creep north to the foothills of the Brooks Range.

The historic glaciations of the North Slope impact the distribution of plant species on the North Slope today (Source: Henry Masters).

It’s June 8th, and as we drive north through Alaska, we also move back through the year, from high summer in Fairbanks to early spring on the North Slope. At elevation, the foothills and mountains of the Brooks Range are shrouded in snow, and brown tundra peaks out below. Dryas octopetala—the frail yet hardy white-blossomed plant eponymous of the Ice Age’s Younger Dryas period—is one of the only alpine flowers in bloom. When summer eventually takes hold, the vegetation patterns on the tundra will reflect the effects of the historic glaciations of the region, according to An. The more time has passed since a given piece of ground was uncovered by ice, the older the bedrock, and the more acidic the soil, an important factor in shaping where plants live. The glaciers have been gone for millennia, but they still influence the plant species composition of the landscape.

Melting permafrost, another relic of the last ice age, causes problems throughout Interior Alaska—“drunken” spruce trees are destabilized and fall over, ground subsides, house foundations crack. Along the Dalton, this melt is even more menacing. We pass hills on which frozen debris lobes creep downslope about 1.5 cm per day, slowly approaching the Dalton, and creating what Timm calls “a lot of hubbub” about the economic giant of the Trans-Alaska Pipeline, which pumps oil 800 miles between Prudhoe Bay and Valdez.

A bull moose drinks from a pond on the side of the Dalton near Coldfoot (Source: Henry Masters).

“Four-wheeler coming up Atigun Pass,” my boss Dan calls over the CB radio. With no response and no semis visibly barreling towards us, we start up the narrow, steep pass, and enter true glacial terrain. The Atigun River Valley, like dozens of others in the Brooks Range, curves in a classic U shape, carved by glacial scour during the last glacial maximum. We pass the campground and airstrip at Galbraith Lake, formed by the damming action of a glacier’s terminal moraine.

“That’s Gates,” Dan points, using the unofficial nickname of a cirque glacier in the distance. “It’s a great day hike to the top. Takes about eighteen hours,” he mentions, so casually that I can’t tell whether he’s joking. He isn’t.

Driving through Atigun Pass in September is a challenge with limited visibility (Source: Emma Boone).

Gates is a prominent cirque glacier in the Brooks Range, located on the northern boundary of the remote Gates of the Arctic National Park. Like other high mountain glaciers in the region, Gates is one of the last remnants of a long, icy history. The entire North Slope landscape tells the story of successive, repeated glaciations, beginning over 2.6 million years ago in the late Pliocene. Passing through this landscape, the significance of these glaciations feels all the more immediate because they bear the names of nearby major rivers: Anaktuvuk, Sagavanirktok, Itkillik. Around 11,500 years ago, the glaciers of the Itkillik II advance made their last retreat to the mountain cirques of the Brooks Range, where they remain, feeding local streams and rivers with seasonal melt.

“Oh look, a siksik,” Dan says, referring to the ground squirrel running straight at our tires by its Inupiaq name. Kames are important habitat for ground squirrels and voles, who burrow easily into the dry mounds. This rodent distribution is apparent around our destination, Toolik Lake, a complex kettle pond surrounded by kames.

As we turn into Toolik Field Station’s driveway, our 285 mile jaunt on the Dalton ends, and the field season begins. The Haul Road continues on to Prudhoe Bay, past more glacial valleys, more moraines, and pingos, ice-cored hills that form in periglacial terrain.

Numerous kettle ponds are visible from the ridge system overlooking Galbraith Lake (Source: Rachel Kaplan).

We, however, will stay here, to spend the summer studying kettle ponds and biogeochemical cycling in the Toolik region, which is another way of studying the historic glaciations of the North Slope. When we sample different lakes, the various times of glacial retreat will leave a signature in the water chemistry. Thermokarsts, defined as sunken land formed by melting ice wedges, cause the tundra to slump into some of our study lakes, impacting their nutrient cycling and discharging carbon into the atmosphere.

But as we drive toward Toolik Field Station for the first time, I know little of this. All I know is that at 68’38”, I am the furthest north I have ever been, in true glacial terrain. This landscape is vast and wild, and after the drive north, I have many questions to ask of it.

Arctic Field Science: An Unruly Harmony

Hiking past the glacial headwaters of the Sagavanirktok River (Source: Jason Stuckey).

It’s 9 p.m. on my 26th birthday, and I’m standing outside a trailer in the middle of the Alaskan tundra. The trailer is my workplace for the summer, and my labmates and I are waving signs— mine reads “You are Alaska”— and cheering for the runners sprinting past us, in the final meters of an obstacle course race. After my throat becomes sore from shouting, I go inside and get back to my work.

I’ve spent the last ten weeks living at Toolik Field Station, a collection of trailers and shipping containers perched on the edge of a lake at 68°38” north latitude, above the Arctic Circle and 350 miles up Alaska’s legendary Haul Road, the unpaved highway that parallels the Trans-Alaska Pipeline. Toolik is a hub for all science Arctic; through the year scientists study wolverine ecology, soil microbes, plant communities, the infamous mosquitoes that flourish here every summer, and far more.

Loading cargo on an R44 helicopter in preparation for a flight (Source: Rachel Kaplan).

I’m at Toolik to work on a long-term lakes ecology study, collecting data about nutrient cycling in Arctic lakes. Over the summer, I’ve walked dozens of miles carrying a backpack loaded with water bottles across the tundra, and spent dozens of hours filtering that water back in the lab. A typical work day may involve a helicopter flight to sample a remote lake, or dancing to Beyonce as I clean the radiation laboratory.

This is what living at Toolik puts into sharp focus: the adventure and comedy of the scientific process. Field science in particular is not the linear, dry, objective trudge that textbooks and media often portray. Environmental data collection is a conversation between ideals and reality, between formulas and theories and the dirt and surprises of the real world.

Sampling the “Fog Lakes” involves a beautiful walk across the tundra (Source: Rachel Kaplan).

Being immersed in that environment is extraordinary. In preparing to write this post, I spoke with other researchers about their experiences at Toolik, and a theme that arose repeatedly was what a collaborative, supportive environment exists at the station. With the goal of data collection paramount, people constantly help one another— aquatics researchers sort plant roots with their friends, and kitchen staff volunteer to assist the station naturalist with vegetation surveys. Competition isn’t productive when you rely on one another for everything, from safety in the wilderness to emotional support.

This summer is a collection of moments that feel impossible. I’ve eaten risotto cakes for lunch on the shore of a remote Arctic lake, seen rainbows from a helicopter, and watched caribou watch us. I’ve laughed so hard that I fell off the side of the tiny packraft we use to deploy instruments and collect water (into the center of the raft, fortunately), and sung “How Far is Heaven” at the top of my lungs while my coworker paddled the rowboat around like a Venetian gondola.

Using a packraft makes it possible to sample remote lakes (Source: Rachel Kaplan).

In addition to the joys, fieldwork comes with inherent challenges, too. Weather is god here, the difference between safety and danger, the helicopter picking you up and a night huddled with your colleagues in a tent. One day, during one of our biggest sampling efforts of the summer, my team was caught in a thunderstorm. We walked away from our metal rowboat, and laid on the flat tundra, watching lightning strikes brighten the fog surrounding us. My coworker fell asleep, using his life jacket as a pillow, and I sheltered my face from the rain and reflected on the fact that, despite the illusion of control you may get from all the planning and logistics that go into any sampling effort, the weather is the one in charge, and no science matters as much as safety.

At the intersection of it all— of successful logistics, benevolent weather, testable hypotheses, and the chaos of a real, breathing ecosystem— is where we do our work, and try to nudge understanding of the Arctic forward. In this delicate balance is an unruly harmony. The search for and ability to find that harmony is what I will take away from Toolik Field Station at the end of summer.