To Inuit, Sea Ice Means “Freedom”

May 13, 2010

  

At the edge of the sea ice, a Barrow resident awaits the return of a seal-skin whaling boat. Photo: Faustine Mercer

Here’s a really interesting story on Shari Gearheard’s NSF-funded people and sea-ice study. Gearheard, a glaciologist from U Colorado’s National Snow and Ice Data Center, combined scientific sea-ice studies with the traditional knowledge of Inuit collaboraters who’ve spent their lives on or near the ice.  The aim: to gain a better understanding of how sea ice is changing in the Arctic–and how community lifeways around the Arctic may be changing in response.  

Gearheard and her collaborators speak extensively in the piece, and what they have to say about the changes they’ve seen in sea-ice conditions is compelling.   

“‘I’m a scientist so when I look at sea ice I see what its properties are. How dense it is. But I remember sitting with the hunters when we were all in Qaanaaq. They looked at the sea ice and the first thing they said they saw was ‘freedom’.  

‘(Sea ice) meant they could hunt for food. It meant they could travel to see relatives on the other side of the water, that they hadn’t seen all year.  

‘That was a very powerful thing for me as a person, not just as a scientist.'”–Shari Gearheard  

* * *

“‘When I was a boy, the ice used to hover around Barrow all year,’ 51-year-old Leavitt said. ‘Now when the ice takes off it doesn’t want to come back. So our hunting is very limited.'”–Joe Leavitt, Barrow resident and whaling captain  

* * *

“‘We used to live as nomads in those days,” Sanguya continued. “After Christmas, when there was enough snow, we’d go out on the sea ice and make igloos.  

‘In those days I didn’t have any math or measurements … or anything like that. But I remember looking down through seal breathing holes and the ice was so thick, they looked like they were tapering away.  

‘Today you don’t see that very much. You’ll probably see 4 feet or 5 feet (down) and that’s it.'”–Joelie Sanguya, Elder and hunter, Clyde River, Nunavut

Hunters in Qaanaaq, Greenland traditionally travel over the sea ice on dog-powered sledges like these. Photo: Hans Jensen

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Being COY

April 21, 2010

Polar bear cubs captured, inspected, and released by Hank Harlow's research team. Photo: John Whiteman

The Bears of Summer is back–that’s John Whiteman’s contribution to a collection of polar research dispatches called Ice Stories maintained by the San Francisco Exploratorium. Whiteman, a PhD student in the University of Wyoming’s Program in Ecology, has returned to Kaktovik on Alaska’s north coast for early spring fieldwork.  He’s part of Hank Harlow’s polar bear physiology study, an NSF-funded research project that aims to understand to what extent warmer summer temps–and attendant changes in sea-ice coverage–may impact polar bears who use the ice as a hunting platform. The Harlow team has been capturing, examining, tagging and releasing bears early and late in the growing season since 2008 to find out if they are successfully feeding during the summer, and if not, how they may be using their own body’s resources (mainly fat) for sustenance.

In his latest post, Whiteman writes about examining a gigantic male, the largest bear he’s ever handled. He also comments on the number of COYs he’s seeing–“COYs” being cubs born around January. The above three are taking a snooze on their bear mama while waiting for  a short-lasting dose of anesthesia to wear off.

So far, the team has had some success in recapturing bears tagged last year and in capturing new ones as well; this is particularly good news given that last fall’s capture and study period was hampered by poor ice conditions that prevented the researchers from safely reaching the bears.


Arctic Stories: New Multi-Media Web site

January 21, 2010

Not your typical office. A research building at Barrow, AK. Photo courtesy Arctic Stories

We’re pleased to welcome Arctic Stories, the brainchild of Purdue University atmospheric chemist Paul Shepson, to the online effort to educate and inform people about arctic research and life. (In 2009, we supported Shepson and others working at Barrow, Alaska, on an international study called OASIS. Shepson headed an NSF-funded study of halogen chemistry.)

With children’s book author Peter Lourie, Shepson has built a multi-faceted Web site with NSF funding to present information on the science, wildlife, climate, and people of the Arctic.

The site features video interviews with natives and researchers like polar bear researcher Steven C. Amstrup of the USGS. It also showcases compelling photographs, and links to science institutions. In short, it’s another fantastic resource for following the ongoing work in the Arctic.

This is helpful as the public strives to understand the myriad messages about climate change, research, and more. With news stories reporting that the Arctic is warming twice as quickly as the rest of the planet, that sea ice is melting, and that species are losing habitat and nourishment, sites like Arctic Ice and ours aim to inform readers about the efforts being made to understand the science behind the phenomena.

The science is complex, designed to measure and help us understand changes in the atmosphere, land, plants and animals, human societies and water in the Arctic. To advance these goals, scientists conduct fieldwork in some of the most extreme environments on Earth–and their experiences are often as compelling as their data.

We encourage readers to check out Arctic Ice as they follow their curiosity about work in the far north.


When the ground collapses like a soufflé: Studying the effect of thermokarst on the Arctic

December 28, 2009

By Emily Stone 

This is the thermokarst failure on a stream leading into the Toolik River on the day Breck Bowden and Michael Gooseff discovered it in 2003. (Courtesy of Michael Gooseff)

Scientists Breck Bowden and Michael Gooseff were flying in a helicopter near Toolik Field Station in 2003, scouting for good field sites for river research when they spotted something peculiar. 

Unlike the crystal clear Kuparuk River nearby, the Toolik River was a muddy brown, an unusual site in the Arctic where tundra streams don’t pick up much sediment because the ground is usually frozen. The men had the helicopter fly upstream to investigate. After 40 kilometers they saw the culprit: a small stream leading into the river had a huge, narrow crater on its shore that was dumping sediment into the river. 

“It was a severe gash on what was otherwise a nondescript hillside,” said Gooseff, an assistant professor of civil and environmental engineering at Pennsylvania State University. 

The feature is what’s known as a thermokarst failure. Thermokarst occurs when ice in the usually solid permafrost melts and the land gives way like a soufflé. When this happens on flat ground, the melted water pools into a thermokarst lake. When it happens on a slope, as was the case along the Toolik, the water rushes downhill and usually into a nearby body of water and the ground slumps after it, causing what’s called a thermokarst failure. 

The helicopter landed by the gash. Bowden, a professor of watershed science and planning at the University of Vermont who is over six feet tall, was engulfed in it when he stood at the bottom. He guesses that it had formed within a few days of their arrival. 

Standing there, he remembers looking around at all the other tiny streams that led into the region’s big rivers and thinking, “It wouldn’t take many of these on the landscape to have a fairly big impact.” 

Bowden is now leading a project that includes Gooseff and 15 other principal investigators to discover what exactly these thermokarst features are doing to the landscape and river networks, and how they form in the first place. They’ve already established that there are many more of them than there were 25 years ago, the likely result of rising temperatures in the Arctic. As more thermokarst failures develop, researchers want to know how the additional nutrients dumped into rivers will affect aquatic ecosystems, how they’ll impact the plant communities that grow back after a thermokarst landslide, and how they’ll change the amount of carbon dioxide and methane being released into the atmosphere — all crucial questions in the study of climate change. 

Breck Bowden explores the thermokarst failure on a stream leading into the Toolik River on the day he and Michael Gooseff discovered it in 2003. (Courtesy of Michael Gooseff)

Downstream of the same thermokarst feature as it looked this summer when the group of researchers began their multi-disciplinary study of the phenomenon. Photo: Emily Stone

The group, which includes another couple dozen graduate students and technicians, is in the first year of a four-year, $5-million grant from the NSF’s Arctic System Science Program. They spent their first field season at Toolik this past summer picking their research sites and setting up equipment to monitor the changes happening in and near the thermokarst failures. 

Previous research by Bowden, Gooseff and some of the other collaborators established that, at least in the area around the field station, there are many more thermokarst failures than there were in the early 1980s. The group did an aerial survey of 600 square kilometers around the station and compared their observations to an aerial survey that was done in the same area around 1980. They found 34 thermokarst, two-thirds of which were new. This data doesn’t necessarily correspond to the rest of the Arctic since different soil conditions, slope and climate affect thermokarst formation, but it does suggest that the features are growing in at least one large swath of Alaska. 

The concern is that these features can have an outsized impact on the environment. 

Bowden is interested in the nutrients that are usually held frozen in permafrost — what he describes as “brown concrete” — that are released into rivers when that permafrost melts. The addition of ammonium, nitrate and phosphate means that aquatic microbes and plants have much more to eat and can flourish in areas where their populations were previously limited by a lack of food. This can dramatically alter a river’s ecosystem. 

He has set up water monitoring stations on rivers above and below thermokarst failures to compare the sediment and nutrients in the water before and after the thermokarst soil reaches it. Earlier research showed that the Toolik River thermokarst failure delivered more sediment to the river than was dumped into the Kuparuk River over the course of 18 years from a 132-square-kilometer section of watershed. 

Other researchers in the group are looking at how plants react to thermokarst failures. “We have a suspicion that what they evolve into is a shrubby community,” Bowden said, instead of the low tundra grasses that dominate the region. 

This is important because shrubs hold on to more sunlight than grasses, which warms the soil below. This can in turn release more stored carbon out of the warming soil. Additionally, warmer soil releases more nutrients for microbes to use as fuel. Microbes then release more methane into the atmosphere, which is a powerful greenhouse gas. Scientists in the thermokarst group are measuring this CO2 and methane release. 

Other researchers are looking at remote sensing and computer modeling, as well as interviewing Native Alaskan communities nearby to learn about their memories of where thermokarst have occurred in the past. 

Gooseff is taking a step back to try to figure out what causes the thermokarst failures in the first place. He has placed water and temperature sensors at various depths in and near several thermokarst features, as well as instruments above ground that measure rain, snow, sun and wind. His post doc, Dr. Sarah Godsey, set up cameras to take pictures of the thermokarsts every hour. Their goal is to be able to correlate the weather and soil data with physical changes in the permafrost and landscape. 

Bowden notes that thermokarst are not a new occurrence. Scientists have been aware of them for years, and engineers have long studied them in the context of building roads, homes and pipelines. 

“It is a natural phenomenon, but it appears to be one that is accelerating,” he said.

Emily Stone is a freelance writer from Chicago, Illinois. She spent a week at Toolik Field Station in 2009 as an MBL journalism fellow.


Northwest Passage: The Making of a Documentary

November 29, 2009

On June 17, 2009, Emmy award-winning filmmaker Sprague Theobald, 58, left Rhode Island on a 57-foot Nordhavn powerboat with a crew of four to document a maritime expedition through the Arctic’s storied Northwest Passage. Once impenetrable, the ice-covered seafaring route became fully navigable for the first time in 2007 when the sea ice dramatically retreated. In 2008, the passage was also clear, and in 2009, Theobald embarked to make a film showcasing the stark wilderness. Able sailors and divers, the crew had never before braved the Arctic. They encountered significantly more ice than expected, but five months, many polar bears and one perilous ice trap later, they emerged safely in Seattle on November 5, 2009, with 250 hours of high-definition footage. This winter, Theobald will distill his material into a full-length documentary. Theobald sat down with us and reflected on his journey.

The Northwest Passage. Sprague Theobald's trip originated in Rhode Island and ended in Seattle five months later.

Polar Field Services: When did you first get the idea for this project?

Sprague Theobald: Years and years and years ago. I was very inquisitive as a kid and when I learned about the Northwest Passage in school, the first thing they said was that man can’t go through it. I hate the word “can’t.” Since then the passage has intrigued me, in part because I knew as I was growing up that if no one was up there going through it, no one had yet left their footprints. 

No footprints here. Theobald and crew make tracks in the Northwest Passage. Photo: Northwest Passage Film

What was your intention/mission when you set out from Rhode Island?

Apart from simply documenting this great expedition, I wanted to show daily shipboard life of a family. But once we got to Greenland and saw the ice and got away from humanity, I saw that nature is so much bigger than any story we could tell from the boat.

What interaction did you have with native communities?

I was hoping to show the life in the communities we went to, but it was very hard to depict daily life. I was also thinking about doing more on the environment and climate change specifically, but then I thought the pictures spoke for themselves.

Would it have enhanced your experience to discuss climate change more and interview more experts?

Well, we interviewed two elders, hunters and two young geologists. Their anecdotal information differed. The elders both said the winters are getting longer and the ice is getting thicker, and the geologists said the ice was changing, seeing more run off. I didn’t want to make a climate change documentary. I wanted to show the pristine place in its rawness.

We do have footage talking about the potential impacts of oil and gas, and prospecting for diamonds and gold and nickel underground.

Were you already a fan of the Arctic or polar places?

Other than a scouting trip in 2008, I had never been there before. But the passage had such a legacy of expeditions trying and, if they made it back, saying it’s hell. My sense of adventure goes deep, and when someone says, “you can’t go there,” I think, “Why not?” 

The view from the boat—for five months. Photo: Northwest Passage Film

What were your first impressions as you reached the Arctic by boat?

It was much different than I expected. I knew it would be isolated and desolate, but it was like the backside of the moon. There was no plant life; we went two months without seeing another boat or another person, and every time anyone went ashore onto the ice, two of us had to go together and we had to have guns.

Describe the environment.

The midnight sun was ethereal with a bluish cast to it. Human faces don’t look pink and healthy—they look blue and gaunt. It is really powerful. The wildlife was stunning.

Describe a typical day.

You wake up four different times and are always busy. You stand watch, are briefed as to what is going on, check the engine room, download the ice charts, weather charts, keep your eyes open for anything—a rogue piece of ice or whales getting ready to jump

What was typical progress and how much fuel did you use?

A good day would be 200 miles and we’d travel between 7.5 and 8 knots. The tank holds 2,200 gallons of fuel and we used a little less than 8,000 gallons, total. We got fuel in Greenland, and topped off the tank in Nome and in Sitka, and that lasted us to Seattle.

What were some of the more interesting shots you filmed?

It was all really stunning. And the underwater footage is incredible. Everyone has seen life above the ice. Seeing the hull of the boat coming through the ice is amazing.

You were stuck on the ice for several days. What happened?

That was horrific. Our options dwindled very slowly and inexorably. We had been anchored off of a small island downloading the ice charts, and saw a lead open in the ice. The next chart came down, and the lead was even bigger, so we went for it. We were halfway in it, when we saw a white wall coming toward us. The wind doesn’t drive the ice, the currents do, and the currents had changed.

On the first day we were trapped, in 18 hours we moved 17 miles. The next day we made two miles in five hours. I went to bed thinking the next thing I was going to hear was the crunch of the ice decimating the boat. But four hours later I woke up, and we were seven miles off the coast, had a small lead, and we pushed and pushed and began to work our way out of it. 

Icebergs show up on the radar. Theobald and crew were trapped in the ice when changing currents closed leads (openings in the ice) that previously looked open. Photo: Northwest Passage Film

What were the potential consequences of being trapped?

We couldn’t move. It was the first time in my life I had ever been without an option. We felt hopeless. We were trapped, caught, not moving. In the worst-case scenario, we would have had to abandon the ship and make our way to the closest civilization over ice.

Did you film during this crisis?

With great precaution we went out onto the ice and got some magnificent footage of the boat trapped. We also dove under the boat and locked in some great shots.

What was the most dangerous aspect of being trapped?

The ice felt like an avalanche in very slow motion, the compasses were all deviating because we were so far north, so we had to rely on GPS to navigate. We dropped anchor on the ice floe, and so we would move with the ice, but the current changed yet again and at one point, instead of being a mile and a half off shore, we were a quarter mile off shore. We were either going to wreck on the rocks or on the ice.

How did you get out of the situation?

Luck. The current changed again, and then we saw a small opening and we went for it as aggressively as we could. When we were finally liberated, there weren’t whoops of joy or loud yahoos. Everyone was so depleted.

You said you have an interest and eagerness to support or inspire the educational/scientific communities with your footage and experiences. What are some ways you envision doing that?

The goal for any documentary is for someone to sit there at the end and say, “I never knew that.” I want to open their eyes a little bit, and if I can develop partnerships with any scientists or educational outlets to use some of my footage to accomplish that, then that would be good.

When will we see the documentary?

It will take about three months to log all the footage, and by the beginning of the summer we’ll have a good rough cut. A lot of people have expressed an interest in seeing the footage, so right now I am working on creating a good five-minute teaser.

Much of your crew was related to you.

Yep, it didn’t start off as a family trip, but my crew included my stepdaughter, Dominique Tanton, 28, and stepson, Chaunce Tanton, 32, and their half brother and my son Sefton Theobald, 22.

This expedition pulled the family back together in a way that was totally unexpected.

When did you decide to make this expedition a reality?

In 2007. I was out to dinner with friends in New York and was asked if there was a trip I hadn’t yet done as a filmmaker, and the words “Northwest Passage” flew out of my mouth and were there on the table. And it was realistic, particularly with the ice opening up that summer. I had a boat, I had crew people in mind, and—this was before the economy fell apart—I had potential sponsors lined up to underwrite it.

Who were your sponsors?

Nordhavn, the boat manufacturer (and I owned a Nordhavn) signed on right away. But last September (2008) the economy began to crumble and they and my other sponsors had to pull out. I completely understood. They didn’t have the money.

How did you pay for the expedition, and what was your budget?

I used the proceeds from the sale of my home several years earlier. It was completely self-funded and cost me about $300,000.

What are your final thoughts on the expedition?

It was an astounding trip. I hope that whatever happens in the future with the Northwest Passage, we all use our brains about it. It truly is one of the last wild adventures.


In the Media

November 19, 2009

Documentary Filmmaker Completes Northwest Passage Trip

 

The M/V Bagan cruises past icebergs as she makes her way through The Storied Northwest Passage. Documentarian Sprague Theobald and Hole in the Wall Productions will bring us stories from their 5-month cruise. Photo: © HITW Productions; http://northwestpassagefilm.com

Filmmaker Sprague Theobald completed a trip through the Northwest Passage, arriving in Ketchikan, AK, Oct. 27 on a 57-foot Nordhavn power boat, reports the Fairbanks Daily News Miner. Theobald and his crew, which included was his son, Sefton Theobald; master diver Greg Deascentis; and cameraman Ulli Bonnekamp, among others, departed Newport, R. I., on June 16. During the journey, the team was hit by an ice floe that trapped their boat in the ice for days. “It was worth the risk, but I would not do it again,” Theobold told Yachting Magazine. “We have yet to talk publicly about the more terrifying moments of the trip.” During the voyage, he interviewed Inuit elders, other sailors attempting the passage, politicians, and conservationists as he collected material for a full-length documentary, Braving the Northwest Passage, forthcoming. Learn more about the adventure at his blog.

Emmy-winning filmmaker Sprague Theobald eyes sea ice from the bow of the Began. Photo: © HITW Productions (http://northwestpassagefilm.com). To visit the Web site, click on the picture.

 
Arctic Commercial Fishing Limits To Go Into Effect Dec. 3

The Associated Press reports that strict commercial fishing limits in the Arctic will go into effect Dec. 3, following a push from the National Oceanic and Atmospheric Administration to develop a plan to regulate commercial fishing in the Arctic in the wake of melting sea ice. The restrictions prohibit industrial fishing in nearly 200,000 square miles of U.S. waters in the Beaufort and Chukchi seas.

 

Much Arctic Warming Linked To Sea Ice, Cloud Cover Changes

Icebergs in Columbia Bay, Alaska, are representative of ice bodies impacted by Arctic warming. Photo: University Corporation for Atmospheric Research

A study published in the Nov., 2009, issue of the journal Geophysical Research Letters asserts that much of the dramatic change documented in the Arctic over the past 20 years correlates with changes in sea ice concentration and cloud cover. Lead author Yinghui Liu (Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin-Madison, Madison, Wisconsin) writes that sea ice loss in the Chukchi and Beaufort seas in the fall account for significant surface warming. Specifically, the researchers analyze the influence of trends in sea ice concentration and cloud cover on surface temperature in the Arctic from 1982 to 2004. They find that sea ice concentration and cloud cover play a large role in observed temperature trends. For instance, their analysis shows that surface warming associated with sea ice accounts for more than 0.9 degrees Celsius (1.62 degrees Fahrenheit) per decade of the observed 1.1 degrees Celsius (about 2 degrees Fahrenheit) per decade warming trend in autumn. In addition, in winter, cloud cover changes explain 0.91 degrees Celsius (1.64 degrees Fahrenheit) of the 1.2 degrees Celsius (2.16 degrees Fahrenheit) per decade surface temperature cooling, and in spring, 0.55 degrees Celsius (0.99 degrees Fahrenheit) per decade of the total 1 degree Celsius (1.8 degree Fahrenheit) per decade warming is attributable to cloud cover. The authors note that their model provides insight into the causes of recent temperature trends and could be extended to study the influences of other parameters such as sea ice thickness.

 

Study Links Climate Change to California Drought

U.S. News & World Report publishes a story that the centuries-long droughts experienced by the state of California over the past 20,000 years coincided with thawing Arctic Ice Caps. The research, published online in the journal Earth and Planetary Science Letters  by UC Davis doctoral student Jessica Oster and geology professor Isabel Montanez, present evidence from analysis of stalagmites from Moaning Cavern and Black Chasm in the central Sierra Nevada. The authors compared climate records from Greenland with the climate records from the stalagmites. At the end of the last ice age about 15,000 years ago, California became much drier. When Arctic records indicate a cooling period about 13,000 years ago, the data show California experienced wetter weather. The scientists don’t offer an explanation for the relationship between Arctic temperatures and California’s precipitation. But the article says that climate models developed by others suggest that “When Arctic sea ice disappears, the jet stream—high-altitude winds with a profound influence on climate—shifts north, moving precipitation away from California.”

 
And Finally…

The Copenhagen Climate Conference is less than a month away (December 6 – 18).


Looking Back to Look Ahead

November 9, 2009

An Air Greenland helicopter arrives to return Jason Briner and his field crew to town after a month in the field studying the rocks and lakes around the Jakobshavn Isbrae. Photo: Jason Briner

As climate scientists attempt to forecast how increases in atmospheric temperatures expedite the melting of polar ice sheets, a team of paleoclimatologists is searching back in time for important clues on the effects of previous climate disruptions. Specifically, the team, led by Dr. Jason Briner (State University of New York, Buffalo), is studying Greenland’s Jakobshavn Isbrae to understand how climate changes during the Little Ice Age and Holocene thermal maximum—a time span of roughly 10,000 to 100 years ago—impacted the glacier’s behavior. Given that the most comprehensive data on the glacier span only about two to three decades, reconstructing the Jakobshavn’s response to climate change over a period of thousands of years will yield insights into the relationship between warming temperatures and glacial trends, said Briner.

“The intent of paleoclimatology is to see what the earth systems are capable of doing in longer time periods and in different climate regimes,” said Briner. “By looking in the past, we have the ability to know what happened when it was 5 to 10 degrees colder or warmer. We are trying to make our research relevant in the context of modern climate changes so we might better understand what might happen in the future.”

Working on the Jakobshavn also provides a unique opportunity to do paleo work on an existing glacier, said Briner.

Jakobshavn Isbrae: The World’s Fastest Moving Glacier

Jakobshavn Isbrae is considered the world’s fastest moving glacier. According to a recent article in the Financial Times, the Jakobshavn Isbrae is perhaps the fastest moving glacier in the world. It drains roughly 6.5 percent of the Greenland ice sheet, and has been documented to be moving at 13 km per year and pouring about 40 km3 per year of ice into the fjord.

In the past two years, Briner and his team conducted a National Science Foundation-supported pilot study to demonstrate the utility of analyzing the glacier’s past. Concentrating on the Holocene period, which began about 12,000 years ago, when average temperatures were about 3 degrees Celsius warmer than they are today, they attempted to identify more precise temperature ranges as well as to understand the glacier’s activity. They also collected information from the Little Ice Age, which followed the middle Holocene warm period and marked a cooling of the earth’s climate from about 600 to 100 years ago.

SUNY-Buffalo undergraduate student William Phlipps and graduate student Shanna Losee take core samples from a big pile of mud that formerly was a lake during the Little Ice Age. As the ice sheet advanced during the Little Ice Age, it blocked a river and created a lake. Once the lake was there, the river valley was buried by silty lake sediments. In the late 1980s, the lake drained out completely because the ice sheet (the lake's dam) retreated, and all the water spilled out. Photo: Jason Briner

Their data came from isotope analysis and radiocarbon dating of lake sediment, as well from three-dimensional maps created using historical photos and an assessment of the insect remains within their lake sediment samples. Although the team’s research focuses on the glacier itself, their detective work took place on the surrounding rocks and in the many lakes on the glacial moraine.

“We work where the ice was, not where it is,” said Briner. “Our geologic record comes from the landscape.”

Will Phlipps and Nicolas Young, PhD student, SUNY-Buffalo, hike along the crest of a moraine deposited during the Little Ice Age. In the distance is the iceberg-choked icefjord, which was occupied by the Jakobshavn ice stream during the Little Ice Age. The ice margin is now about 20 km away. Photo: Jason Briner

Lakes Rich With History

These lakes serve as conservatories of glacial debris, which drained into them when the Jakobshavn melted and retreated over time. Briner and his team study sediment cores from the lakes to date the contacts, which is how they confirmed the glacier advanced during the Little Ice Age.

“Until the Little Ice Age, the lakes had no glacial meltwater input,” said Briner. “The ice margin advanced during the Little Ice Age close to pre-existing lakes, but not over them.  In fact, it advanced just barely close enough that it spilled its melt water into the lake basin and ultimately the silt particles in the ice sheet melt water were deposited in the lake, which, prior to that, just had the organic sediments. When the glacier retreated, its margin receded back out of the lake’s drainage basin.”

Shanna Losee, Nicolas Young, and Will Phlipps on a coring platform on one of the lakes in the study area. Photo: Jason Briner

Putting the Puzzle Together

The team aims to reconstruct the climate and establish a more specific temperature record that spans the Holocene period. Currently scientists have a broad understanding of the average temperatures during the Holocene, but those temperatures varied significantly depending on altitude and location, said Briner.

“We are trying to get a record from our site and quantify the changes in ecology to get a local temperature record to see if it syncs with what the glacier was doing,” he said

The research at Jakobshavn is similar to research Briner and fellow scientists recently completed at the Sam Ford Fjord in Canada’s Baffin Island. Similar climate reconstruction efforts found that 9,500 years ago, the fjord’s kilometer-thick glacier melted in a “geologic instant” during a climate-warming period. Like the glacier in Sam Ford, Jakobshavn is sitting in a similarly deep fjord. Briner said the Baffin Island work revealed the significance of glaciers that lie in very deep water.

“When glaciers that calve retreat into deeper water, that promotes further retreat,” he said. “And that amplifies the retreat rate.”

The Jakobshavn is one of these glaciers; the calving front is in only 800 meters of water, but people who have done radar surveys discovered that most of Jakobshavn resides in a trough that is 1,400 meters below sea level. Once the Jakobshavn starts to retreat, it likely will continue retreating quickly, much like the glacier in Sam Ford did almost 10,000 years ago.

“With the Sam Ford, the glacier retreat was triggered by a warming climate,” said Briner. “This mechanism having to do with water depth was superimposed on the warming and made the response drastic. We reconstructed the relative instant disappearance of the glacier.”

That raises questions about the Jakobshavn. Specifically, when did it retreat in the past, what were the retreat rates, and were those associated with climate warming, said Briner. Preliminary conclusions are that the Jakobshavn Isbrae is tightly linked to climate change. The glacier’s fastest retreat rates occurred in the middle Holocene, at the height of the warmest temperatures. Then, when the Little Ice Age occurred, there was a rapid response and glacial growth—the glacier advanced about 35 kilometers—followed by significant retreat of 30 kilometers since the modern, 20th century warming began, said Briner.

“This tells us that when there is a climate perturbation, Jakobshavn has a really monstrous response,” he said.

Improving Climate Change Models

This information could help improve the accuracy of climate models. Currently the Intergovernmental Panel on Climate Change (IPCC) is hampered by a lack of models that can accurately predict complex ice flow. By incorporating long-term, historic data and reconstructed climates, modelers will have a critical baseline by which to measure what the ice sheet did then and simulate potential actions it may take now, Briner said.

And though this specific research project on the Jakobshavn was only a two-year pilot study on the feasibility, Briner is confident much more research remains.

“Our initial project is limited in scope and we’ve had great success in doing what we said we were going to,” Briner said. “The possibilities for what’s next are big.”

In fact, one of Jason Briner’s next projects is huge: he leads the U Buffalo component of a 10-institute collaborative funded by NSF and led by Darrell Kaufman (U Northern Arizona). The investigators will collect lake sediments all over the Arctic for very detailed climate history information going back about 8000 years.  Read our recent conversation with Darrell Kaufman here.