Research

Sediment records provide a glimpse into Iceland鈥檚 past, and hope for its future

Gabe Allen — Tue, 13 May 2025 21:38:08 +0000

Sediment records provide a glimpse into Iceland鈥檚 past, and hope for its future Gabe Allen Tue, 05/13/2025 - 15:38

Gabe Allen

Just a couple of kilometers inland from the coast of Northern Iceland, lie Torfdalsvatn, a small, deep freshwater lake. Winters here are frigid, snowy and dark, save a few hours of muted daylight. Lucky visitors might catch a glimpse of the Northern Lights when the clouds clear.

Most travelers opt to visit the region in the summer, when conditions are more temperate, but for paleoclimate researchers, winter is the perfect time for a trip to Torfdalsvatn. That鈥檚 because the mud that lies below the lake holds an exceptionally detailed record of Earth鈥檚 past. And, in the winter, researchers can bring the cumbersome equipment needed to drill down into the mud right out on the ice with them.

鈥淵ou can drive right out onto the ice and drill through with an ice auger,鈥� CIRES research scientist and INSTAAR affiliate David Harning explained. 鈥淚t鈥檚 much harder in the summer when you鈥檙e out in a little boat trying to anchor it and it鈥檚 windy and our boat is getting dumped on.鈥�

Last month, Harning, along with American and Icelandic collaborators, published a new analysis built on decades of research at Torfdalsvatn. The study brings diverse analytical methods together to provide a highly detailed picture of past climatic conditions, soil stability and plant life at the site.

One clear takeaway was that Torfdalsvatn鈥檚 soils and plant communities remained exceptionally resilient, when compared to other sites in Iceland. It鈥檚 an insight that is more than a piece of history鈥攊t could help conservationists better plan for the future.

鈥淪oil erosion is one of the biggest problems in Iceland right now,鈥� Harning said. 鈥淯nderstanding the resilience or fragility of certain areas to future changes in soil erosion is really important to conserving these landscapes.鈥�

Fire and ice in the mud

Since 1992, researchers have looked to the sediments below Torfadalsvatn to understand the past 12,000 years of climatic conditions in Iceland. The site is an exceptionally good model of the past for two reasons.

Firstly, sediment piles up at the bottom of Torfadalsvatn at an unusually high clip, leaving researchers more mud to analyze. Secondly, Torfadalsvatn was one of the first lakes to emerge, when the giant ice sheet that once stretched across Iceland began to retreat 12,000 years ago. As a result, the lakebed houses some of the oldest sediment in the country.

The winter 2020 field team operates a sediment coring device on a clear day. Left to right: Jonathan Raberg (Postdoc, University of Wyoming and former INSTAAR PhD), Gifford Miller, and 脕slaug Geirsd贸ttir. Photo courtesy of David Harning.

Over the past three decades, much of the work on Torfadalsvatn鈥檚 sediment record has been done by two researchers and their students: INSTAAR faculty fellow Gifford Miller and University of Iceland professor of geology 脕slaug Geirsd贸ttir.

Harning, a former student of both, was brought in on the project during his PhD studies at INSTAAR. Between other projects, he worked to identify layers of volcanic ash in the sediment (Iceland is known as 鈥渢he land of fire and ice鈥� because of its plentiful active volcanoes).

Over the lifetime of the project, several other researchers devoted countless hours to other analyses. These included identifying algal pigments and geochemical markers, proxies for past plant communities and climate respectively.

In the new study, Harning pairs these previous analyses with a suite of techniques meant to place each data point more precisely in time.

脕slaug Geirsd贸ttir prepares the sediment coring device at Torfdalsvatn. Due to the lake鈥檚 high sedimentation rates, this 3 meter long tube will only recover around 3,000 years of mud. Multiple subsequent cores are then required to collect the entire 12,000 year history. Photo courtesy of David Harning.

鈥淏y establishing the chronology and locking sedimentary history in time, we could start to ask some of these longstanding questions that our group has been interested in,鈥� he said.

One of these questions, perhaps the most controversial one, concerns soil erosion and human settlement. There is a longstanding theory that Norse settlers caused widespread soil erosion and ecological degradation when they arrived in Iceland a millenia ago. Recent research has called this narrative into question, suggesting that these changes could have been kicked off by environmental changes even further in the past.

Harning鈥檚 analysis, though, complicates the theory even further. The researchers estimated that erosion and vegetation changes at Torfadalsvatn didn鈥檛 escalate until around 200 years after the arrival of settlers. Perhaps something about the site made it more resistant to whatever factors caused degradation elsewhere.

鈥淲e weren鈥檛 expecting that,鈥� Harning said. 鈥淭his implied that the site, which is coastal and at a low elevation, had some sort of natural resilience to the processes that were causing soil erosion elsewhere.鈥�

Looking Forward

Harning urges that further research should look into what made Torfadalsvatn so resilient. The question is still relevant today, as Icelandic land managers and farmers search for ways to combat soil erosion and deforestation on the landscape.

Harning and his colleagues鈥� recent paper could also provide useful information for other scientific fields. The analysis provides an exceptionally detailed record of past volcanic events, many of which had not been previously identified. If corroborated, these markers could provide, essentially, a time stamp in the sediment record to aid future research.

鈥淚t鈥檚 a ton of information about volcanic history,鈥� Harning said. 鈥淢aybe someone else finds another link, and then you have new marker layers.鈥�

Finally, the new analysis provides a huge amount of information relating past climatic conditions to ecological conditions. This information isn鈥檛 only useful for researchers curious about ancient history, it could also help scientists look to the future.

鈥淭hese high resolution records are a key data constraint for any Earth system model that鈥檚 trying to predict future climate change,鈥� Harning said. 鈥淚f you have a good understanding of the physics of the system, you can run that model forward.鈥�

A new investigation, led by INSTAAR affiliate David Harning, uncovers a story of ecosystem resilience at a lake in coastal Iceland. The analysis could aid future conservation and climate modeling efforts.

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INSTAAR and University of Iceland researchers extracting a sediment core from an Icelandic lake in February 2020. Photo courtesy of David Harning.

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INSTAAR and University of Iceland researchers extracting a sediment core from an Icelandic lake in February 2020. Photo courtesy of David Harning.

An apple a day? It鈥檚 the Boulder way (Colorado Arts and Sciences Magazine)

Gabe Allen — Mon, 12 May 2025 22:04:54 +0000

An apple a day? It鈥檚 the Boulder way (Colorado Arts and Sciences Magazine) Gabe Allen Mon, 05/12/2025 - 16:04

The Boulder Apple Tree Project, led by INSTAAR fellow Katharine Suding, has broken ground on a new apple orchard on 30th Street in Boulder. The orchard will provide shade, fruit and a site for agroecology research. It is supported by a $90,000 sustainable 麻豆免费版下载grant.

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Spring runoff is older than you think (University of Utah)

Gabe Allen — Thu, 08 May 2025 15:56:27 +0000

Spring runoff is older than you think (University of Utah) Gabe Allen Thu, 05/08/2025 - 09:56

INSTAAR alum Paul Brooks led this study, which found that more of the Rocky Mountain spring runoff comes from groundwater than previously thought. The results could help water managers, cities and farmers. INSTAAR faculty Holly Barnard is a coauthor.

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Arctic plants react unexpectedly to climate change, study says

Gabe Allen — Wed, 07 May 2025 20:42:43 +0000

Arctic plants react unexpectedly to climate change, study says Gabe Allen Wed, 05/07/2025 - 14:42

Gabe Allen , Rhona Crawford

Rapid climate change is upending plant communities in the Arctic, with species flourishing in some areas and declining in others, according to a new study in Nature.

The decades-long investigation, led by researchers at the University of Edinburgh, compiled data from 1981 to 2022 on more than 2,000 plant communities across the Arctic tundra. Analysis revealed shifting patterns in plant species composition, abundance and growth during a period of unprecedented change.

Researchers use a point frame while surveying plant species on Qikiqtaruk-Herschel Island in the Canadian Arctic. Photo courtesy of Jeff Kerby.

Sarah Elmendorf, an INSTAAR faculty fellow and research associate in the department of Ecology and Evolutionary Biology, was a coauthor on the paper. She stressed the outsized importance of Arctic environments to both people and life on Earth.

鈥淭he Arctic holds a huge amount of the world鈥檚 carbon,鈥� she said. 鈥淚t also has resources that are used by animals and people, and a vast amount of biodiversity that isn鈥檛 found anywhere else.鈥�

According to Elmendorf, a better understanding of Arctic plant community鈥檚 responses to climate change could help us conserve them down the line.

鈥淚f we understand how biodiversity is changing over time, and the relationship to climate change, we can understand how it might change in the future,鈥� she said.

The Nature paper identified a few key trends. In many areas shrubs and grasses are proliferating and shading out fragile flowering plants. The result is an overall decrease in plant diversity at these sites.

Interestingly, the researchers found evidence against a oft-cited hypothesis鈥攖hat climate change would cause Arctic plant communities to become more similar to each other.

鈥淚n fact, they鈥檙e changing in all sorts of directions. It鈥檚 a little less cut and dry,鈥� Elmendorf said.

Though Arctic plant communities aren鈥檛 becoming more homogenous, yet at least, Elmendorf warns against seeing this with rose-tinted glasses. In totality, the analysis revealed widespread change. And, according to the authors, these vegetation changes can be an early warning signal for ecosystem-level changes with knock-on effects for animals, humans and the planet鈥檚 natural carbon storage systems.

鈥淥ften when we think about climate change impacts on the planet we think about biodiversity loss, but in the temperature-limited tundra, climate change is multi-faceted,鈥� said Isla Myers-Smith a coauthor on the Nature paper and professor at the Universities of Edinburgh and British Columbia. 鈥淭aken together, our study indicates that biodiversity can follow diverging trajectories in the rapidly warming Arctic.鈥�

Rhona Crawford is the PR & Media Manager for the University of Edinburgh

If you have questions about this story, or would like to reach out to INSTAAR for further comment, you can contact Senior Communications Specialist Gabe Allen at gabriel.allen@colorado.edu.

A team of 54 researchers, including Sarah Elmendorf, analyzed more than 42,000 field records of Arctic plant communities over a span of 41 years. Their insights are essential to understanding how Arctic environments are changing in the modern era.

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Tundra plants make the most of the short summer in Ellesmere Island, Nunavut. Photo courtesy of Anne Bjorkman.

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Tundra plants make the most of the short summer in Ellesmere Island, Nunavut. Photo courtesy of Anne Bjorkman.

INSTAAR faculty among those awarded undergraduate research grants (UROP)

Gabe Allen — Wed, 30 Apr 2025 20:44:19 +0000

INSTAAR faculty among those awarded undergraduate research grants (UROP) Gabe Allen Wed, 04/30/2025 - 14:44

The Undergraduate Research Opportunities Program committed $77,000 in grants for 麻豆免费版下载undergraduates to work with INSTAAR faculty this summer and next school year. The awards will catalyze opportunities for students to contribute to critical research in earth and environmental science.

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The ocean may be absorbing less carbon, but it may not be due to climate change鈥攜et (麻豆免费版下载Boulder Today)

Gabe Allen — Tue, 29 Apr 2025 21:05:38 +0000

The ocean may be absorbing less carbon, but it may not be due to climate change鈥攜et (麻豆免费版下载Boulder Today) Gabe Allen Tue, 04/29/2025 - 15:05

An INSTAAR-led study found that recent dips in the ocean鈥檚 carbon absorption are likely due to natural variability instead of global warming. Institute director Nicole Lovenduski urges that future research needs to employ remote devices to gather more field samples.

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Earth Day: 6 sustainability stories from INSTAAR in 2025

Gabe Allen — Tue, 22 Apr 2025 23:41:24 +0000

Earth Day: 6 sustainability stories from INSTAAR in 2025 Gabe Allen Tue, 04/22/2025 - 17:41

Gabe Allen

INSTAAR researchers investigate fundamental questions about ecosystems, climate systems and landscapes.

Today marks the 55th annual Earth Day, a global celebration of our planet, its natural systems and the idea of a sustainable future. In honor of the occasion, INSTAAR is sharing stories from the first four months of 2025 about INSTAAR鈥檚 environmental research.

As mountain glaciers melt, risk of catastrophic flash floods rises for millions (The Conversation US)

Last month, INSTAAR faculty research scientist Alton Byers and Wesleyan University professor of earth science Suzanne OConnell wrote a guest article in the Conversation US. The pair, a mountain geographer and earth scientist respectively, described how melting glaciers are amplifying the risk of catastrophic flooding in mountain communities around the world. Some governments and organizations, including the U.N., have focused efforts on research into mitigation tactics and early effective warning systems.

Franklin Institute selects Katharine Suding for the Bower Award for Achievement in Science

Next month, INSTAAR faculty fellow and professor of distinction in ecology and evolutionary biology Katharine Suding will officially receive the Bower Award for Achievement in Science from the Franklin Institute. The award honors prominent scientists and innovators who have changed the world for the better. Suding is a preeminent restoration ecologist who has left an indelible mark on the concepts of ecosystem resilience, restoration and biodiversity.

Desert reservoirs capture and store organic carbon, according to new research

Dams have long been a controversial topic among environmentalists. While they can sometimes harm aquatic ecosystems, they can also provide benefits, like increased water storage. Recently, a group of INSTAAR researchers uncovered another potential benefit of certain reservoirs. In a recent paper, they describe how one large reservoir in New Mexico captures and stores carbon beneath layers of sediment during droughts and flash floods.

Drone experiment reveals how Greenland ice sheet is changing (麻豆免费版下载Boulder Today)

Kevin Rozmiarek is a drone enthusiast, but he鈥檚 not just a hobbyist. He鈥檚 using unmanned aircraft to do science. In a recent publication, Rozmiarek and his colleagues documented changes in Greenland鈥檚 ice sheet. Their study relied on samples of atmospheric water vapor collected by drones, an approach that could improve simulations of sea level rise.

International research collaboration uncovers key driver of Himalayan glacier melt

This winter, INSTAAR research scientist Karl Rittger lent his talents to an intercontinental team of scientists seeking to understand exactly how and why Himalayan glaciers are melting. Rittger鈥檚 unmatched methodology for analyzing dust-covered snow from satellite imagery led the team to key insights. They found that dust storms were picking up pollution from heavily populated areas and depositing it on the mountains.

New research demystifies carbon cycling in freshwater lakes around the world

Back in 2019, INSTAAR faculty fellow Isabella Oleksy, then a PhD student, put out a call to collaborators for data on phytoplankton activity in freshwater lakes. In the end, researchers from all over the world contributed to the dataset. Oleksy and collaborators then used the data to refine a mathematical model of primary productivity for freshwater lakes. The new model could help earth scientists better understand the carbon cycle, which could lead to better climate predictions.

INSTAAR researchers investigate fundamental questions about ecosystems, climate systems and landscapes. These six stories highlight the environmental research that the institute is doing in 2025.

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Major dust-up for water in the Colorado River (University of Utah)

Gabe Allen — Mon, 21 Apr 2025 20:13:39 +0000

Major dust-up for water in the Colorado River (University of Utah) Gabe Allen Mon, 04/21/2025 - 14:13

A new study unveils a powerful dataset quantifying snow darkening and its impacts on snowmelt across the Colorado River Basin in real time. INSTAAR research scientists Karl Rittger and Sebastian Lenard are co-authors on the University of Utah-led paper.

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The data is in: Colorado鈥檚 snowpack is lagging behind the 21st century average in 2025

Gabe Allen — Thu, 10 Apr 2025 16:30:00 +0000

The data is in: Colorado鈥檚 snowpack is lagging behind the 21st century average in 2025 Gabe Allen Thu, 04/10/2025 - 10:30

Gabe Allen

A new modeling tool from INSTAAR provides weekly snow-water equivalent estimates for the entire Western US.

Last week, INSTAAR鈥檚 Mountain Hydrology Group released its fifth near-real-time report on snow-water equivalent (SWE) in the Western US in 2025. In essence, the report provides a snapshot of how much water is stored in snow on the landscape鈥攚ater that will feed our rivers and streams in the months to come.

The end-of-March report is of particular interest for water managers in the West, because it arrives around the time that snow in the region reaches its peak. Last week鈥檚 report will help managers adjust plans for the spring, summer and fall.

鈥淚t helps inform how much water storage they might have and when that might come down into their reservoirs,鈥� INSTAAR PhD student and report co-author Emma Tyrrell said.

Other tools for visualizing the snowpack exist, such as the Natural Resources Conservation Service Snow and Water Interactive Map, which plots various SWE-measuring stations. But, the Mountain Hydrology Group鈥檚 reports take a uniquely comprehensive approach. The team combines multiple data sources and modeling tools to estimate the amount of water stored in snow across the entire landscape.

The skinny

A map showing the percent of the long-term (2001 to 2021) average snow-water equivalent in major regions of the Western United States as of March 31, 2025.

Here in the Front Range, the report shows SWE totals lagging behind the 2001 to 2021 average. However, the overall trend doesn鈥檛 hold at all elevations. While the plains and foothills have less snow than average, many mountainous areas, like the headwaters of the Colorado River, sport average or higher-than-average snowpacks.

鈥淲here you might go skiing, we鈥檙e seeing around 100% of normal,鈥� Tyrrell said.

If you zoom out to the entire Western US, the report shows some anecdotal regional trends. The Desert Southwest has had a dry winter, with many regions dipping below 50% of average SWE and some in the single digits. On the other hand, a pocket of mountainous regions in the Northwest, stretching from Western Wyoming to Oregon, is experiencing an unusually robust spring snowpack.

鈥淲e鈥檙e seeing a somewhat typical north to south gradient during a La Ni帽a cycle,鈥� senior professional research associate Leanne Lestak told INSTAAR.

An experiment, a product

The Mountain Hydrology Group, led by INSTAAR faculty fellow Noah Molotch, has been producing SWE reports for the Sierra Nevada Mountain region in California since 2012. There, water managers and river forecasters have come to rely on the reports.

鈥淲e work really closely with the California Department of Water Resources." Lestak said. 鈥淭he hydrologic engineers use our data in their forecasts, and they really rely on what our reports have to say. It鈥檚 such an honor to work with these folks.鈥�

The west-wide report is a newer endeavor鈥攖he group put out the first of its biweekly reports this February. Like the Sierra Nevada reports, the west-wide reports draw on a mix of satellite imagery, remote snow sensors and statistical modeling to arrive at its estimates. When they can, the team also calibrates their results by comparing them to 鈥淎irborne Snow Observatories,鈥濃€攊ntermittent snow surveys conducted via manned aircraft in Colorado and elsewhere.

鈥淲e consider them a ground truth,鈥� Tyrrell said. 鈥淚t鈥檚 a patchwork of data that we can use to bias correct.鈥�

While the methodology that the 麻豆免费版下载team uses for the Sierra Nevada reports has been refined by years of tweaking, the west-wide methodology is still new鈥攊t鈥檚 an experimental product. It will take a few years for the team to refine the model and build trust with stakeholders.

Locally, the project has already garnered some interest.

鈥淒enver Water and other local cities are interested,鈥� Lestak said. 鈥淭here aren鈥檛 a lot of products here on the Front Range.鈥�

We may have reached peak SWE for 2025 here in the west, but the Mountain Hydrology Group will keep issuing reports until mid summer. All the while, they will work to refine their tools.

If you have questions about this story, or would like to reach out to INSTAAR for further comment, you can contact INSTAAR Communications Specialist Gabe Allen at gabriel.allen@colorado.edu.

A new modeling tool from INSTAAR provides weekly snow-water equivalent estimates for the entire Western US. It has already caught the attention of local and regional water managers.

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Deploy, recover, sample, deploy... A day in the life of a CTD Watchstander (GO-BGC)

David J Lubinski — Fri, 04 Apr 2025 17:48:30 +0000

Deploy, recover, sample, deploy... A day in the life of a CTD Watchstander (GO-BGC) David J Lubinski Fri, 04/04/2025 - 11:48

Grad student Genevieve Clow is currently working aboard a research vessel on a 41 day expedition to the Indian Ocean. Read her blog post about gathering hydrographic measurements and collecting water samples.

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Research

Sediment records provide a glimpse into Iceland鈥檚 past, and hope for its future

Fire and ice in the mud

Looking Forward

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Spring runoff is older than you think (University of Utah)

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Arctic plants react unexpectedly to climate change, study says

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INSTAAR faculty among those awarded undergraduate research grants (UROP)

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The ocean may be absorbing less carbon, but it may not be due to climate change鈥攜et (麻豆免费版下载Boulder Today)

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Earth Day: 6 sustainability stories from INSTAAR in 2025

As mountain glaciers melt, risk of catastrophic flash floods rises for millions (The Conversation US)

Franklin Institute selects Katharine Suding for the Bower Award for Achievement in Science

Desert reservoirs capture and store organic carbon, according to new research

Drone experiment reveals how Greenland ice sheet is changing (麻豆免费版下载Boulder Today)

International research collaboration uncovers key driver of Himalayan glacier melt

New research demystifies carbon cycling in freshwater lakes around the world

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Major dust-up for water in the Colorado River (University of Utah)

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The data is in: Colorado鈥檚 snowpack is lagging behind the 21st century average in 2025

The skinny

An experiment, a product

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Deploy, recover, sample, deploy... A day in the life of a CTD Watchstander (GO-BGC)

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