To listen to the full interview, please head to CJOB.

Rivkin and researchers from Environment and Climate Change Canada, Polar Bears International, MacEwan University, Government of Northwest Territories, and San Diego Zoo Wildlife Alliance developed an innovative SNP genetic sequencing chip, a new tool, to analyze samples from polar and grizzly bears. Their report analyzed 371 historic polar bear and 440 historic grizzly bear samples from across Canada, Alaska, and Greenland and confirmed that only the eight already-known are hybrids, thus underscoring the rarity of hybridization. 

Range expansion, facilitates hybridization of two large carnivores

“Polar bears evolved from grizzly bears several hundred thousand years ago and although gene flow has occurred between the two species in the past, it appears that recent hybridization is restricted to a small group of polar bears and brown bears in the western Arctic,” says co-author Evan Richardson, Research Scientist at Environment and Climate Change Canada, adding, “This study develops a new genomic toolset to rapidly detect hybrids and indicates that contemporary hybridization is not a conservation concern.” 

Hybridization, increasing but rare

This report answers the question of, “How many polar-grizzly bear hybrids are there?” which responds to an expectation that the numbers of polar-grizzly hybrids were increasing. Out of 819 wild grizzly and polar bears across Canada, Alaska, and Greenland, encompassing four subpopulations, this report found that only eight hybrids exist, or 1 per cent of the samples, collected between 1975 and 2015. The first hybrid did not appear until 2006. While it is a rare occurrence, it is a recent one, suggesting hybridization is a result of warming temperatures causing their habitats to increasingly overlap. 

“We were surprised to find no new cases of polar-grizzly hybrids despite speculation of increasing numbers,” says Rivkin, who also co-authored the study. “We’re proud that this new chip allows rapid identification of polar-grizzly bear hybrids, which will be an important tool as the climate warms and polar and grizzly bears come increasingly into contact.”

About hybrids (also known as pizzly bears or grolar bears)

Hybrids of grizzly and polar bears are often referred to as grolar or pizzly bears depending on the paternal lineage, i.e., a grolar bear when the father is a grizzly bear, and a pizzly bear when the father is a polar bear. This study confirms the existence of eight known grolar bears in the wild as the descendants of one female polar bear. Hybridization is only possible in areas where grizzly and polar bear distributions overlap (thus excluding regions like the high Arctic). Hybridization is uncommon but expected to increase as climate change pushes grizzly bears northward, increasingly into polar bear territories, but hybrids are still ill-suited to adapt to the changing Arctic. 

“This report underscores that hybridization is remarkably rare, and that hybridization is not an adaptive capability of polar bears,” says Geoff York, senior director of research and policy at Polar Bears International, who was not involved in the report. “The report introduces a new tool for wildlife managers to use as they evolve their strategies due to a warming climate and changing ecosystems.” 

Technological breakthrough

This research developed the new 8K genotyping chip, called the Ursus maritimus V2 SNP chip, which is a genetic tool used to analyze polar bear samples in a lab. It reads the genetic samples, allowing rapid and reliable genome analysis and spots polar bear-grizzly hybrids with 100 per cent accuracy. The Ursus maritimus V2 SNP chip is a result of years of development through the Genomics Research and Development Initiative STAGE funding by Environment and Climate Change Canada. The authors had access to long-term, robust polar bear data from Canadian government and territorial monitoring programs, which have been collecting data since 1966, and which were critical to the research and Ursus maritimus V2 SNP chip development. This chip is an important tool for wildlife managers, scientists, policymakers, and conservationists to identify hybrid bears and further enable their protection and more effective wildlife management. 

“Our newly developed technology allows rapid and accurate consideration of over 8,000 genetic markers in polar bears,” notes lead author Dr. Joshua Miller, Assistant Professor, Biological Sciences, MacEwan University, adding “This will allow for the assessment and monitoring of genetic diversity, which is a key part of a species’ ability to survive changing environmental conditions.”

“In July the sea ice was smaller than the long-term average by an area nearly four times the size of Manitoba.” – Robbie Mallett

Mallett and Nandan specialize in radar remote sensing of sea ice properties. Specifically, they aim to develop algorithms to interpret satellite data on the reflection of radar waves from the ice cover. The third team member of their winter-long field campaign is a radar instrument (“KuKa”) designed to mimic the instruments mounted on the European Space Agency’s satellite missions. KuKa was designed and funded through Professor Julienne Stroeve’s position as a Senior Canada 150 Research Chair, which also funds Mallett and Nandan’s work. Through their collaboration with the British Antarctic Survey’s DEFIANT project, the team is also equipped with instrumentation to measure the light that’s reflected and transmitted through the sea ice and its snow cover, and a high-resolution laser scanner that maps the snow surface as it transforms over the winter.

Robbie and Vishnu working a on thin sea ice cover near the station. Photo Vicki Warke, British Antarctic Survey

While Mallett and Nandan have been working on the ice, unfortunately, KuKa has had to stay home due to the record-breaking low sea ice conditions. “While Vishnu and I can work dynamically and respond to hazards from the thin ice as they emerge, unfortunately, KuKa can’t do the same,” says Mallett, “so considering that she’s worth over half a million dollars, we decided to wait until the ice thickens a bit more before letting her out”. Mallett and Nandan have however been able to install other instruments on the ice such as the light meters, and have collected sea ice cores for isotopic and chlorophyll analysis in their lab.

“It’s been a historically difficult season to work on the ice here,” says Nandan. “We’re super vulnerable to the wind here – when it blows from the land onto the sea, the ice can break away from the shore and drift away from the station. We need to be sure we and our instruments aren’t on it when that happens. Last week we saw the ice dramatically break away from the shore as the wind direction shifted unpredictably”. When the sea ice or wind conditions aren’t suitable, Mallett and Nandan have been working on a nearby glacier, trying to improve satellite measurements of Earth’s thinning ice sheets with their radar and laser scanners. 

Vishnu setting up the laser scanner while “KuKa” the sled-mounted radar gathers data on the snow cover.

At the time of writing, Antarctic sea ice continues to track well below last year’s levels which were themselves record-breaking. Stroeve is the PI of the field campaign in Antarctica and has been watching the conditions closely this year. She told us “Sea ice performs so many critical functions in Antarctica: it reflects sunlight and cools the planet, it keeps marine ecosystems healthy and productive, and its annual formation helps drive the global ocean circulation pattern. So it’s been a shock to see the numbers sitting so far outside what we’ve seen over the last four decades. While the role of climate change in this record-breaking event has yet to be quantified, this year’s conditions are clearly cause for concern”.

“Stroeve and her team have pushed the frontiers of research by leading this alarming discovery of melting Antarctic sea ice, which is clearly cause for concern,” said Mario Pinto, Vice President (Research and International) at the University of Manitoba. “UM is at the forefront of climate change research, with a focus on better understanding the importance of the Antarctic and Arctic in determining climate policy and evaluating the impacts of climate change. This story showcases UM’s impact on the global stage by spearheading world-leading expertise in climate action and turning these discoveries into solutions for tomorrow.”

This is the first time a deep ice core has been drilled through an ice stream, and the ice at the base is more than 120,000 years old. Researchers have discovered the ice stream is flowing like a river of ice ripping itself free from the surrounding slow flowing ice sheet, with rock and sand embedded at the bottom of the ice.

Dahl-Jensen has confirmed that the ice is indeed melting at the base, signaling trouble ahead. The ice core will be analyzed in laboratories around the world to better understand the changing ice sheet and improve sea level predictions.

“I am so excited about this success,” says Dahl-Jensen. “I have followed the flow of the ice by measuring the shape of the borehole through the years with a borehole logger. The fact that the ice is sliding like a block on mud will change the models and improve the sea level predictions.”

The first ice cores were drilled exactly 7 years ago on July 21, 2016. Research in the field in 2020 and 2021, were cancelled due to COVID-19. The last four meters of the ice core was drilled with a rock drill set up due to the presence of pebbles in the ice. The very last core was drilled July 21, 2023.

Dorthe Dahl-Jensen and team of international researchers celebrate milestone in climate change research in Greenland.

“I would like to extend my congratulations to Dorthe on this remarkable accomplishment in climate change research,” said Mario Pinto, Vice President (Research and International). “UM is proud to lead this important milestone in Arctic science and climate change research. We are confident this result will increase awareness and knowledge of how rapidly the effects of climate change are transforming our planet.”

The international EGRIP project has researchers from 12 countries including the U.S., Germany, Japan, Norway, Switzerland, China, and Sweden. The logistics have been led by the University of Copenhagen and U.S. National Science Foundation. Samples from the ice cores have been analyzed in more than 30 laboratories and the first of several papers have been published. More information on the project, publications and fieldwork can be found on eastgrip.org. 

This is the second exciting breakthrough around understanding climate change for Dahl-Jensen. She and a group of researchers from 15 other international institutions recently discovered that 20 per cent of Greenland was green 416,000 years ago and that the current Greenland ice sheet is more vulnerable to melting from human-caused climate change than previously thought. That study was published in the journal, Science.

Listen to the interview

Read more

The results shed light on the stability of the Greenland ice sheet over the last two and a half million years. Moderate warming led to melting of at least 20% of the total Greenland Ice sheet volume. These results suggest that the ice sheet is more vulnerable to melting from human-caused climate change than previously thought – and will be vulnerable to rapid melting in coming centuries.

University of Manitoba Professor Dorothe Dahl-Jensen is the lead scientist on the team. She is a Canada Excellence Research Chair in Arctic Ice, Freshwater-Marine Coupling and Climate Change in the Centre for Earth Observation Science (CEOS) at the Clayton H. Riddell Faculty of Environment, Earth and Resources.

“This discovery suggests a tundra and forest covered Greenland landscape many years ago and warns of melting of the full ice sheet if warming continues” said Dorthe Dahl-Jensen. “Unless we can dramatically lower the concentration of carbon dioxide in the atmosphere, this is the future we are facing. A newly granted ERC Synergy grant ‘Green2Ice’ will allow us to continue these studies and include all the deep Greenland ice cores”.

The scientists used sediment from the first ice core drilled in Greenland at Camp Century, a secret U.S. Army base in the 1960s, to make the discovery. They applied advanced luminescence and isotope techniques to provide direct evidence of the timing and duration of the ice-free period.

Research camp including the central dome structure and accommodation units.

Under-ice laboratory in the research camp where analysis is conducted. The orange light is used to preserve the luminescence of the samples.

Bettina Ovgård Petersen, Senior Consultant Civil Military Cooperation, Science Liaison Officer, Joint Arctic Command of Denmark holding a 90,000 year old, 3 cm thick slab of ice core from the beginning of the ice age.

UM’s Vice-President of Research and International Dr. Mario Pinto was able to join the research team in Greenland recently to learn more about their work.

“Congratulations to the entire science research team, including UM’s Dr. Dorthe Dahl-Jensen, on this discovery and pivotal moment in climate change research,” said Dr. Mario Pinto, Vice President (Research and International). “I was pleased to join the group in Greenland recently and tour Camp Century. The knowledge they have uncovered will help build our collective understanding of melting Arctic ice and the consequences of climate change world-wide.”

Mario and Dorthe in her lab in the Dome structure above ground.

Mario and Dorthe standing at the entrance to “The Pit” and access to the underground labs.

All photographs provided by Dr. Mario Pinto, Vice-President (Research and International).

Dorthe Dahl-Jensen, a UM professor and Canada Excellence Research Chair at the Centre for Earth Observation Science, is one of the scientists featured in the documentary. The film is an adventure on an epic scale, as she and fellow internationally renowned scientists Alan Hubbard and Jason Box traverse the Greenland ice sheet and explore some of the harshest environments on the planet in the name of science. 

Dahl-Jensen has dedicated her career to understanding the scale of the climate crisis and its implications for the future. Her involvement in the documentary came after Ostenfeld contacted her with an adventurous proposal to help uncover some answers to the questions that she and other climate scientists had been asking for a long time. Namely, how fast is the Greenland ice sheet melting and what future are we heading towards as oceans rise? 

Ostenfeld, in an interview with Variety, called the mystery of the rate at which the ice sheet is melting the “world’s most dangerous uncertainty”. 

The centerpiece of the visually stunning documentary is a dizzying sequence in which Hubbard and director Ostenfeld rappel down a so-called “moulin”, a vertical well-like shaft within the ice sheet created by melting water. As they make their dangerous, jaw-dropping descent down the 180-meter-deep hole secured only by a rope, the pair gain unprecedented insight into the rapidity of the ice melt. 

“It has been a very positive experience,” Dahl-Jensen says of working with Ostenfeld. “He is very good at working together – so he looks then asks and plans and then we go. He rarely asks you to do things just for the movie but likes to film what you are doing.” 

Dahl-Jensen has spent much of her impressive career studying the arctic ice and has been conducting scientific studies in the harsh Greenland environment since 1981. In 2020, she led a team of international scientists there to study the one-of-a-kind fossil plants and sediment from the bottom of the island. That same year, she was awarded the International Mohn Prize for outstanding Arctic research.  

“My work drilling an ice core through the biggest ice stream on the Greenland ice sheet fits very well in the documentary,” says. Dahl-Jensen. “We want to learn how the ice slides and moves fast to the outlet fjords where the ice breaks off as icebergs and contributes fresh water to the ocean. It’s an important source of mass loss from the Greenland ice sheet.”  

Dahl-Jensen and the makers of “Into the Ice” hope that the important research they have collected through drilling and exploring the inland ice will help provide more accurate modelling and increase awareness of how rapidly the effects of climate change are transforming our planet.  

“The Greenland ice sheet is reacting to the warming climate,” she says regarding the conclusions of her study. “This leads to melt and mass loss from the Greenland ice sheet contributing strongly to the sea level rise and changing the conditions in the oceans around Canada and Greenland.” 

“Into the Ice” premiered in March at the Copenhagen Documentary Film Festival. Watch the trailer here. 

In 1966, US Army scientists drilled down through nearly 1,390 meters of ice in northwest Greenland, and pulled up a more than three meter tube of dirt from the bottom. The frozen sediment was moved to a freezer in Copenhagen in 1994 and forgotten. In 2017, the sample was again moved to a new freezer and the frozen sediments were accidentally rediscovered.

In 2019, two samples of sediments were studied by a team of scientists from Denmark and the US, and the team couldn’t believe what they saw: twigs and leaves instead of just sand and rock. That suggested that the ice was gone in the recent geologic past—and that a vegetated landscape, perhaps a boreal forest, stood where a mile-deep ice sheet stands today.

Over the last year, an international team of scientists – led by Dorthe Dahl-Jensen at the University of Manitoba and University of Copenhagen, Andrew Christ and Paul Bierman at University of Vermont, and Jean-Louis Tison at Université Libre de Bruxelles – studied the one-of-a-kind fossil plants and sediment from the bottom of Greenland. Their results show that most, or all, of Greenland has been ice-covered the last million years and ice-free for a period before this time.

“Ice sheets freeze and preserve material in a very pristine way,” says Dorthe Dahl-Jensen, Canada Excellent Research Chair at University of Manitoba.

“But it is a miracle to directly discover delicate plant structures perfectly preserved. They’re fossils, but they look like they died yesterday. It’s a time capsule of what used to live on Greenland that we wouldn’t be able to find anywhere else.”

The discovery helps confirm a new and troubling understanding that the Greenland ice has melted off entirely during recent warm periods in Earth’s history—periods like the one we are now contributing to with human-caused climate change.

Understanding the Greenland Ice Sheet in the past is critical for predicting how it will respond to climate warming in the future and how quickly it will melt. Since some seven meters of sea-level rise is tied up in Greenland’s ice, every coastal city in the world is at risk. The new study provides the strongest evidence yet that Greenland is more fragile to climate change than previously understood—and at grave risk of irreversibly melting off.

“This is a very urgent problem,” says Dahl-Jensen. “Sea level change will impact a significant part of the global population within the next 50 years.”

The new research was published March 15 in the Proceedings of the National Academy of Sciences. (PNAS).

Beneath the Ice

The material for the new PNAS study came from Camp Century, a Cold War military base dug inside the ice sheet far above the Arctic Circle in the 1960s. The hidden purpose of the camp was a super-secret effort, called Project Iceworm, to hide 600 nuclear missiles under the ice close to the Soviet Union. As cover, the Army presented the camp as a polar science station.

The military mission failed, but the science team did complete important research, including drilling a 1,390 meter-deep ice core. The Camp Century scientists were focused on the ice itself, being the first deep ice core ever drilled. The stable water isotopes measured by professor Willi Dansgaard was the first climate record from ice cores and became an important part of the burgeoning effort at the time to understand the deep history of Earth’s ice ages. They apparently took less interest in a bit of dirt gathered from beneath the ice core. Then, in a truly cinematic set of strange plot twists, the ice core was moved from an Army freezer to the University at Buffalo in the 1970s, to another freezer in Copenhagen, Denmark, in the 1990s, where it languished for decades—until it surfaced when the cores were being moved to a new freezer.

For much of the Pleistocene—the icy period covering the last 2.6 million years—portions of the ice on Greenland persisted even during warmer spells called “interglacials.” But most of this general story has been pieced together from indirect evidence in mud and rock that washed off the island and was gathered by offshore ocean drilling. The extent of Greenland’s ice sheet and what kinds of ecosystems existed there before the last interglacial warm period—that ended about 120,000 years ago—have been hotly debated and poorly understood.

The new study makes clear that the deep ice at Camp Century—some 120 km inland from the coast and only 1300 km from the North Pole—entirely melted at some time within the last million years and was covered with vegetation, including moss and perhaps trees. The new research lines up with data from two other ice cores from the center of Greenland, collected in 1990s. Sediment from the bottom of these cores also indicate that the ice sheet was gone for some time in the recent geologic past. The combination of these cores from the center of Greenland with the new insight from Camp Century in the far northwest give researchers an unprecedented view of the shifting fate of the entire Greenland ice sheet

The team of scientists used a series of advanced analytical techniques—none of which were available to researchers fifty years ago—to probe the sediment, fossils, and the waxy coating of leaves found at the bottom of the Camp Century ice core. For example, they measured ratios of rare forms—isotopes—of both aluminum and the element beryllium that form in quartz only when the ground is exposed to the sky and can be hit by cosmic rays. These ratios gave the scientists a window onto how long rocks at the surface were exposed vs. buried under layers of ice. This analysis gives the scientists a kind of clock for measuring what was happening on Greenland in the past. Another test used rare forms of oxygen, found in the ice within the sediment, to reveal that precipitation must have fallen at much lower elevations than the height of the current ice sheet, “demonstrating ice sheet absence,” the team writes. Combining these techniques with studies of luminescence that estimate the amount of time since sediment was exposed to light, radiocarbon-dating of bits of wood in the ice, and analysis of how layers of ice and debris were arranged—allowed the team to be clear that most, if not all, of Greenland melted at least once during the past million years—making Greenland green with moss and lichen, and perhaps with spruce and fir trees.

In a 1960s movie about Camp Century created by the Army, the narrator notes that “more than ninety percent of Greenland is permanently frozen under a polar ice cap.” This new study makes clear that it’s not as permanent as we once thought. “Our study shows that Greenland is sensitive to natural climate warming, but significant warming is needed to melt the full Greenland ice sheet, a state we will reach in the future warming climate,” says Dahl-Jensen.

Media Contact:

Sam Swanson
Communications and Outreach Coordinator
Centre for Earth Observation Science
University of Manitoba
Phone: +1 (204) 590-8591
E-Mail: samuel.swanson@umanitoba.ca

What is your full name, and your position?

My full name is Juliana Marini Marson, and I am an assistant professor at CEOS.

What attracted you to the University of Manitoba?

Well, I’d been looking for a tenure-track position for a while, and when this particular position opened up, I was very excited because it was exactly the type of research I wanted to do. So, I thought maybe now the stars are aligned and this will work out for me. And so it did. My husband and I moved from Brazil to Canada five years ago, and we have loved living here, no matter in which city. And once we came to Winnipeg and got to know a bit of the city, we already liked it. So, all ended up very well for me.

What would be your superpower?

I think I’d like to be as fast as Flash, just so I could visit my family in Brazil for a weekend and come back really quickly. That would be useful.

What’s your favourite place in the world?

That’s an interesting question. I’ve visited several beautiful places, but I would say my favourite place is my home, especially my bedroom. I love that moment at the end of the day when I can finally sit down on my bed and gather some thoughts and read a book or watch something to relax.

Who do you follow on social media?

Mostly my family and friends, just to keep them updated on our life in Canada. I also follow some funny pages like “Pet Portraits by Hercule” or Nathan W. Pyle – super recommend if you are not familiar with them, and some science-, animal-, parenting-related pages. But honestly, nowadays I barely have time to check out social media.

What would people be surprised to learn about you?

I don’t know if this is surprising or just embarrassing. But I have a pretty hard time spelling out loud. If I have to spell something, I have to write it down first. It’s not that I don’t know the correct spelling of things, but my brain just stops working when I have to say the individual letters out loud. I don’t know if I am a tad dyslexic, but this certainly puts me in some awkward situation sometimes.

What is your main research focus?

My main research focus is studying the polar oceans – the interactions between ocean and ice and climate. I’m especially interested in how warming and increasing freshwater, especially coming from melting glaciers, ice caps, and ice sheets, in the oceans. They are affecting physical processes like ocean circulation and other biogeochemical processes, such as primary productivity and carbon sequestration. And the main tools that I use to study the polar oceans are numerical models. I’m also quite interested in icebergs – their drift patterns, their physical and ecological impacts on the ocean, how these will change in the future, and how they will affect socioeconomic activities that are affected by them.

Is there a story behind what attracted you to your research area?

I decided to be an oceanographer when I was 12. That’s when I took an intensive, three-day marine biology course. I just fell in love with it and decided I wanted to study anything related to the ocean.

What is the most difficult thing you’ve ever done?

Ah, I think becoming a mom. Not necessarily labour, although that’s pretty difficult, but becoming a parent. I am an anxiety-driven person who likes their routine and having things under control. When a child comes into your life, all that is out of the window. Also, all the high-level math courses I’ve done were just insanely difficult because they were taught by geniuses. That’s why one of my life’s missions, to explain hard things in simple ways so everyone can understand them.

What is one experience that changed your life?

I don’t think there was this one thing that made everything change. I think every major change in my life came from a process, usually involving the search for who I am and what is my purpose in life. This long-term type of reflection really makes you focus on what is important and changes the way you see everything around you.

What is your greatest indulgence?

Ice cream? Yeah, that’s one thing that I just can’t live without.

What is your favorite movie or book?

I have several favourites, but one book that comes to mind is I Know Why the Caged Bird Sings, from Maya Angelou. It’s one of her autobiographies, and it’s just beautifully written. It shows what this woman had to overcome during her life and how she became an incredible person nevertheless. It’s truly inspiring. I’ve even named my daughter after Maya Angelou, and I hope she is strong as her namesake.

How do you like to relax?

Binge-watching TV shows, playing video games or reading when I have time to myself. Otherwise, playing with my daughter and petting my dog are things that help a lot to de-stress.

What are you reading or watching right now?

I’m reading a book called Erebus [by Michael Palin] which recounts the ship’s voyages and its final demise in the Northwest Passage. It’s quite interesting getting to know the people whose names were used to name straits, channels, and sounds in the Canadian Arctic.

What is your greatest fear?

Maybe one fear is dying without doing something meaningful for other people. The other one is regarding the safety of my daughter. That’s a normal maternal fear, I guess.

If you’re singing karaoke, what would your song be?

Ah, probably a nursery rhyme since those are high up on my playlist right now! Five little ducks?

What is your most treasured possession?

My computer – it was the first one I built and it has everything I wanted in terms of configuration, so I can use it both for work and for gaming.

What personal trait are you most grateful for having?

I’m patient. I’m very patient. I’m really grateful for that, especially now with the pandemic when we have to spend all day at home with family.

What three people would join you for your dream dinner party?

Oh, wow. I would say my three grandparents who have passed away. I barely knew my grandfather on my father’s side when he passed. So that would be a great opportunity to know him better. But I grew up with both my grandparents on my mother’s side, and I just miss them so much.

What would you say is your best quality?  And what would you say is your worst?

My best quality is that I’m very organized with my work stuff. All my notes are very neat, and I usually have all my ducks in a row work-wise. My worst quality is that I’m not super organized with my personal stuff. I leave things in places they don’t belong – I function well in a kind of organized mess, if you will. But my husband is a neat-freak, so he gets a bit cranky with me sometimes.

If you did not take this career path, what would you have chosen?

I’d have chosen music if not oceanography by the time I finished high school. I played the clarinet for a long, long time and I loved it very much. But if you asked me what other path I’d choose today, I’d say computer science or astrophysics.

In November 2020, NASA and the University of Manitoba highlighted a few compelling features around the Thomsen River estuary on Banks Island, including lines of sea ice tracing the shoreline and the braided pattern of the river. But there’s so much more to explore across this remote lowland tundra and river valley. 

January 27th, 2021 by Kathryn Hansen/NASA Earth Observatory, and Robie Macdonald/University of Manitoba/Dept. of Fisheries and Oceans

Robie Macdonald, a scientist at the Centre for Earth Observation Science at the University of Manitoba, shared some photos that he shot while doing fieldwork in the region between 2014 and 2016. The purpose of that project was to collect geochemical measurements from small rivers across the Canadian Arctic Archipelago. 

“I really do love working in these places,” Macdonald said. “Once the aircraft has landed, one is bathed in a tremendous silence broken only by waves breaking on shingle. Then you have this incredible tundra spreading out toward the hills that define the river floodplain.” 

Here are ten of Macdonald’s favorite photographs.  

1. Ponds and Oxbows

“Numerous ponds of all sizes populate the drainage basins of Banks Island, and you can see several clusters of them in the satellite image (top), especially along the small river to the west of the Thomsen. This photograph provides a closer look at one such pond cluster. In the image, you can also see textbook oxbows, which have become the setting for more ponds.”

2. Permafrost Polygons

“During breeding season, it seems like almost every pond on Banks Island has its own population of snow geese (visible in this photo). You can also see old permafrost polygons that are now submerged within the pond. Polygons are widespread features of the permafrost in soil-rich locations and are produced over time by freeze-thaw cycles of the surface active layer. Permafrost thaw is widely impacting these regions, leading to feedbacks in the carbon system (CO2, CH4).”

3. Vibrant Vegetation

“Perhaps the most surprising characteristic of the valley bottoms in this ‘Arctic desert’ is the vibrant color of the vegetation: yellows, greens, and reds mark a dense ground cover that can be seen on the satellite image as areas with a yellowish-brownish cast.” Robie Macdonald/University of Manitoba

4. Sediment Ripples

“As a result of the strong sediment supply, the large embayment at the Thomsen River mouth has been practically filled with sediment. The shallow water reveals itself in the satellite image by the lighter-greenish tone compared to water out in the channel north of Banks Island. More evidence of the ample sediment supply can be seen in beautiful displays of sand/silt ripples in the lower river between the islands. In the satellite image (top), the ripples are almost visible as grey zones between the islands before the river enters the open bay.”

5. Ice Shoves

“When walking on these islands near the river mouth, you can see evidence of bank erosion and ‘ice shoves.’ These are produced when wind forces newly formed ice to ride up over the river bank and gouge out the top layer of the silty material that makes up these islands. Unfortunately, ice shoves are too small to show on the satellite image.”

6. Vulnerable Permafrost

“Global warming and the extensive loss of sea-ice cover in late summer have helped accelerate coastal erosion and permafrost slumping. This image shows a section of coastline just to the east of the Thomsen River mouth that consists of a lot of frozen ice. This sort of permafrost is especially vulnerable to the changing temperature regime.”

7. Erosion and Slumping

“Thaw slumps are also a sign of the permafrost warming. These can be seen just barely in the satellite image as small dark regions along cliff faces–both facing the ocean and within the river drainage basins. Erosion and slumping expose ancient organic carbon to the air and the hydrosphere, thus providing an extensive positive feedback to climate warming.” Photo by Robie Macdonald/University of Manitoba

8. Bergy Bits

“Lines of bergy bits has collected along a thin shore margin at the point where the sea bottom rapidly deepens below ice keel depths, likely at approximately 2-4 meters. Although the grounded ice bits are continually melting, they are resupplied by more ice chunks shed from the permanent pack out in the channel. Two turbid plumes supplied by a river to the west of the Thomsen easily pass through the necklace of ice.”

9. Sampling Amid an Icy Barrier

“When we were sampling the water in this region, we found this ice barrier to be a bit more of a problem to navigate in our small inflatable boats, but ice along the shore did make it simple to sample sea ice. This image shows Greg Lehn preparing to launch our boat.”

10. A Suitable Landing Spot

Sampling in the Thomson River itself was somewhat simpler, once we had found a suitable place to land the plane. This image shows Greg Lehn scoping out the shore of the Thomsen River near its mouth.”

See the article as originally published by NASA Earth Observatory here.