Science

When Rivers Meet the Sea: Carbon Cycling in the Gulf of Alaska

Posted by on Aug 3, 2017 in All Posts, Featured Posts, Science | 0 comments

When Rivers Meet the Sea: Carbon Cycling in the Gulf of Alaska

Spread the News:ShareWhen rivers meet the sea, the sediment they carry becomes mixed into the ocean, where it makes quite a splash, biogeochemically speaking. In the subarctic North Pacific Ocean, for example, iron-rich sediment delivered from the continental margin spurs a wintertime phytoplankton bloom over 900 kilometers offshore. The presence of these terrigenous particles is felt up the food chain— the higher levels of iron in the water support larger diatom populations, which means more snacking for copepods, a type of zooplankton. In the Gulf of Alaska, glacial meltwater is an important source of terrestrial particles. A recent study by Jessica Turner, Jessica Pretty, and Andrew McDonnell optically measured particles in the northern Gulf of Alaska, an area with extensive glacial inputs. This technique allowed the researchers to collect massive amounts of data with minimal lab work, maximizing the area they could survey, Jessica Pretty told GlacierHub. Their instrument measured a range of particle sizes, from some too small to be seen by the naked eye to others as large as paper clips. Pretty and her coauthors found that in the Gulf of Alaska, particle concentrations are denser in two main places: where glaciers and rivers flow into the Gulf, and offshore, near the continental shelf break, where they are buoyed by waves, currents and tidal action. These small particles wield great influence, increasing biological productivity at the shelf break. “The Gulf of Alaska is an interesting region,” said Pretty. “It has major freshwater input seasonally from melting glaciers and river runoff that eventually joins with Pacific waters and makes its way toward the Arctic.” The recent findings illuminate particle distribution in the northern Gulf of Alaska, yielding clues about how climate change may affect carbon cycling in the Gulf and parallel ocean systems. Beyond local significance to the Gulf of Alaska ecosystem, the influence of these river-borne terrestrial particles scales up— globally, such sediment inputs impacts the carbon cycle, which regulates climate. The bits of rock Pretty tracked in the Gulf of Alaska are essentially tiny bundles of carbon, and when these bundles sink in the ocean, they drive what scientists have termed the “biological pump,” the process by which the ocean cycles organic and inorganic carbon, and sequesters carbon dioxide in the deep ocean. Because carbon dioxide is constantly exchanged between the upper layers of the ocean and lower levels of the atmosphere, concentrations become equal in the shallow ocean and low atmosphere over time. However, sinking particles remove carbon from this exchange. “The biological pump allows the ocean to store more carbon than it would be able to just from equilibration,” explained Pretty. The ocean absorbs a quarter of the carbon dioxide released into the atmosphere each year, and so as carbon is pumped into the atmosphere, levels in the ocean increase in tandem. This leads to ocean acidification, which threatens many marine species. However, terrestrial carbon sequestration practices, like soil conservation and wildfire suppression, may be an important element of climate change mitigation. As global climate warms and glaciers melt, higher glacial inputs will carry more sediment to the Gulf of Alaska and analogous ecosystems around the world. These minute particles will ramp up the global biological pump, increase carbon sequestration, and lead to a myriad of impacts yet unknown. In addition, seasonal changes, like an earlier springtime, may also spur earlier phytoplankton blooms, changing the dynamics of life in the sea. Through the movement of minuscule specks of rock, the Gulf of Alaska, and ultimately the whole ocean, will change. Spread the...

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Roundup: Crack, Flood, Fight

Posted by on Jul 31, 2017 in All Posts, Featured Posts, News, Policy and Economics, Roundup, Science | 0 comments

Roundup: Crack, Flood, Fight

Spread the News:SharePetermann Crack Develops From Grist: “Petermann is one of the largest and most important glaciers in the world, with a direct connection to the core of the Greenland ice sheet. That means that even though this week’s new iceberg at Petermann is just 1/500th the size of the massive one that broke off the Larsen C ice shelf in Antarctica earlier this month, it could eventually have a much bigger effect on global sea levels. Scientists believe that if Petermann collapses completely, it could raise the seas by about a foot.” Read more about the potential collapse of the Petermann here.   Glacial Outburst Flood Rages in Iceland From The Watchers: “A glacial outburst flood started in Iceland’s Múlakvísl river around midnight UTC on July 29, 2017. Electrical conductivity is now measured around 580µS/cm and has increased rapidly the last hour, Icelandic Met Office (IMO) reported 10:14 UTC on July 29. Increasing water levels of this river are an important indicator of Katla’s upcoming volcanic eruptions.” Read about safety concerns associated with the flood here.   Conflict in the Himalayas From The New York Times: “The road stands on territory at the point where China, India and Bhutan meet…The standoff began last month when Bhutan, a close ally of India, discovered Chinese workers trying to extend the road. Now soldiers from the two powers are squaring off, separated by only a few hundred feet. The conflict shows no sign of abating, and it reflects the swelling ambition— and nationalism— of both countries. Each is governed by a muscular leader eager to bolster his domestic standing while asserting his country’s place on the world stage as the United States recedes from a leading role.” Learn more about the geopolitics of this standoff here.   Spread the...

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Hunt for Lost Plots in Glacier Bay Yields Key Data

Posted by on Jul 27, 2017 in All Posts, Featured Posts, News, Science | 0 comments

Hunt for Lost Plots in Glacier Bay Yields Key Data

Spread the News:Share20th century ecologist William Skinner Cooper has a long legacy. He spurred the establishment of Glacier Bay National Park and was one of the first American scientists to use the technique of aerial photography. His name lives on through Alaska’s Mt. Cooper and the biggest award offered by the Ecological Society of America. That legacy continues in new and unexpected ways in Glacier Bay National Park with a treasure hunt to find nine plots established by Cooper there in 1916. Cooper developed the plots in order to study how vegetation develops after glacial retreat. As soil evolved and buried the marker stakes, the plots were lost. A century after Cooper began his experiment, Brian Buma, professor of ecology at University of Alaska Southeast, was determined to relocate the plots and launched the hunt. Such bridges between the past and present are what national parks are all about, according to Glacier Bay National Park ecologist Lewis Sharman. In 1916, Cooper recognized that Glacier Bay was changing rapidly as its glaciers retreated and exposed new land to primary plant succession. “Glacier Bay is one of the most dynamic landscapes on earth,” said Lewis. “It’s the quintessential national park in that it encompasses a landscape with great scientific value. Scientists here are like kids in a candy store.” “It was the most fun I’ve ever had on any science project,” added Buma, who recently published his results in the journal Ecology. “It had everything: adventure, old documents, old-school orienteering.” The first clues to the plots’ whereabouts came from a paper Cooper published based on his trip to the area in 1916. “The directions literally read “‘From large rock, walk 30 degrees east 40 paces, to small cairn.’ It was very Indiana Jones,” said Buma. The project’s National Geographic funding included a trip to the archives in Minnesota that house Cooper’s original field notes. Some notebooks are stained by water and others burnt by sparks from campfires, according to Buma. His research in the archives pointed to “Teacup Harbor,” a distinctive round inlet in the West Arm of Glacier Bay. Buma decided to start there, in a search he called “truly for a needle in haystack.” Magnetic north has changed by eleven degrees since Cooper’s day, so the original compass bearings were wrong, and large boulders Cooper used as landmarks are now cloaked by plants. Isostatic rebound, the rise of land formerly depressed by the weight of a glacier, also transformed Glacier Bay’s landscape and confounded Buma’s search. Rebound has dramatically changed Teacup Bay’s shoreline and the distance of some plots from the water. Undaunted, the team headed to Glacier Bay. Their search process involved scouting from a boat, matching the landscape before them with photographs from the 1970s, and “stumbling around the woods looking at 100-year-old sketches, trying to decipher what a ‘pace’ was,” said Buma. At a likely site, they’d use a metal detector to hunt for the stakes framing the meter square plots. Cooper’s experience locating the plots would have been far less arduous. A distance Cooper would have tromped in five minutes across the gravel takes thirty minutes or longer today, tortuously zigzagging through brush, according to Buma. “I’d love to know what he’d think if he could come back and see the plots,” said Buma. Bushwhacking through willows up to five meters tall and staying vigilant for bears, the team found the first three plots fairly quickly, but it took four days to find the next. One plot was lost to erosion in the 1930s, but by the end of their search, the team had found the other eight. Locating the oldest...

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Life on the Rocks: Climate Change and Antarctic Biodiversity

Posted by on Jul 20, 2017 in All Posts, Featured Posts, Science | 0 comments

Life on the Rocks: Climate Change and Antarctic Biodiversity

Spread the News:ShareBy now, it’s a familiar story: climate change is melting glaciers in Antarctica, revealing an increasing proportion of ice-free terrain. The consequences of this melt are manifold, and one may be surprising: as more ground is bared, Antarctic biodiversity is expected to increase. Currently, most of the terrestrial biodiversity— microbes, invertebrates, and plants like grasses and mosses— occurs in the less than one percent of continental Antarctica that is free of ice. A recent Nature article predicted that by the end of the 21st century, ice-free areas could grow by over 17,000 square kilometers, a 25 percent increase. This change will produce both winners and losers in Antarctica’s ecosystems, according to Jasmine Lee, lead author on the above paper, and the game will be problematic. “Some of the winners are likely to be invasive species, and increasing invasive species could negatively impact the native species,” Lee told GlacierHub. “More isn’t necessarily better if new species are alien species.” The Antarctic Peninsula, an 800-mile projection of Antarctica that extends towards South America,  is one of the fastest-warming places on Earth, and 80 percent of its area is covered by ice. The many outlet glaciers of the Antarctic Peninsula Ice Sheet primarily shrink through surface melting, which reduces volume, while tidal action spurs calving. Lee and her coauthors constructed two models based on two Intergovernmental Panel on Climate Change (IPCC) climate forcing scenarios. Under the strongest IPCC scenario, ice-free areas in the peninsula are expected to increase threefold, and Lee expects biodiversity changes in this region to be obvious by the year 2100. She predicts that some native species will expand their ranges south in response to the creation of new habitat and milder conditions, and invasive species will thrive for the same reasons. This pattern is already apparent in the distribution of a number of penguin species. As climate warms, sea ice-obligate species like Adélie and Emperor penguin are shifting and contracting their ranges southward, seeking sea ice. Likewise, ice-intolerant gentoo and chinstrap penguins, typical of the Subantarctic latitudes, are moving south as the ocean becomes increasingly free of ice. As temperatures continue to rise, this biogeographic chess will play out increasingly across Antarctica. “The greater the degree of climate change, the greater the biodiversity impacts,” predicted Lee. She added that counting an Adélie colony in a “real-life ice-free area” was a highlight of her fieldwork. Interestingly, Lee and her coauthors found that higher biodiversity in the short-term may yield greater homogeneity in the long-term, as invasive species become established and potentially out-compete native species. It’s hard to know how to feel about these ecosystem-wide transitions, said Lee. “The fact that we are driving these changes through anthropogenic climate change should remind us that our actions impact the entire earth, even in what we consider the remotest and most pristine regions. I think we should feel accountable and know that because humans have the power to change the earth, we should do our best to look after it,” she said. On June 1, President Donald Trump made a speech announcing the United States’ exit from the Paris climate agreement, obfuscating international cooperation on climate change mitigation. Lee feels this decision sends the wrong message to the rest of the world, but she hopes that the United States will find a way to continue meeting the environmental standards set forth. “America should be a leader in renewable energy technology and policy. However, I am also hopeful that the American businesses and states can reach the Paris accord milestones for America in spite of Trump. And this will show that...

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Roundup: Seals, Flood Mitigation, and Freezing Levels

Posted by on Jul 17, 2017 in All Posts, Featured Posts, Roundup, Science | 0 comments

Roundup: Seals, Flood Mitigation, and Freezing Levels

Spread the News:ShareSeal Whiskers Detect Ecosystem Change From Polar Biology: “Warm Atlantic water in west Spitsbergen have led to an influx of more fish species. The most abundant marine mammal species in these fjords is the ringed seal. In this study, we used isotopic data from whiskers of two cohorts of adult ringed seals to determine whether signals of ecosystem changes were detectable in this top marine predator.” Find out more about ringed seals here.   Flood Mitigation Strategies in Pakistan From Natural Hazards: “The frequency and severity of flood events have been increased and have affected the livelihood and well-being of millions of people in Pakistan. Effective mitigation policies require an understanding of the impacts and local responses to extreme events, which is limited in Pakistan. This study revealed the adaptation measures adopted in Pakistan, and that the local policies on disaster management need to be improved to address the barriers to the adoption of advanced level adaptation measures.” Find out more about flood risk mitigation in Pakistan here.   Rising Freezing Levels in Tropical Andes From AGU Publications: “The mass balance of tropical glaciers in Peru is highly sensitive to a rise in the freezing level height (FLH). Knowledge of future changes in the FLH is crucial to estimating changes in glacier extents. Glaciers may continue shrinking considerably, and the consequences of vanishing glaciers are especially severe where people have only limited capacity to adapt to changes in the water availability due to, for instance, lack of financial resources.” Find out more about freezing levels in Peru here.   Spread the...

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Shining on a Glacier: Girls on Ice

Posted by on Jul 13, 2017 in All Posts, Art/Culture, Featured Posts, Science | 0 comments

Shining on a Glacier: Girls on Ice

Spread the News:ShareOne day last June, something rare took place on Interior Alaska’s Gulkana Glacier— a dance party. As a treat for the final day of Girls on Ice, a glacier-based science education program for teenage girls, instructors lowered each of the nine girls into a crevasse, two at a time, and they used ice axes and crampons to climb out. The day was chilly and the winds were picking up, and the girls started dancing to keep warm. “They were dancing and laughing and shining,” said glaciologist and Girls on Ice instructor Aurora Roth. “I want to hang on to that forever. That’s why I do what I do, to see girls shining in the outdoors.” Girls on Ice began in 1999 when a team of two instructors and five teenage girls spent a week exploring the South Cascade Glacier in Washington. In 2012, a group of graduate students from the University of Alaska Fairbanks decided to adapt the program to Alaska. Each June, eight or nine girls join up with female mountain guides, scientists, and artists to spend a week on the Gulkana Glacier studying glacial processes, creating art, and exploring themes from climate change to socially-prescribed gender roles. “The wilderness setting and single gender field team inspires young women’s interest in science and provides a challenging environment that increases their physical and intellectual self-confidence,” states the program’s mission statement. Pervasive and dangerous gender imbalances in the geosciences necessitate this focus on girls’ physical and intellectual self-confidence. M Jackson, a glaciologist and environmental educator, is troubled by gender dynamics in the sciences today. “While there are women in glaciology, it is not simply an issue of metrics, the number of women in the field, or the number of women-authored publications. I can tell you from personal experience that out in the field on glaciers, in years past, I have almost always been the only woman on the team. This is changing today,” she said. Joanna Young, one of the founders of the Alaska Girls on Ice program, seeks to instill a diverse skill set in each girl she teaches, and show them that there are many ways to view the world. A typical day for the girls might include monitoring a snowmelt experiment near camp, a painting lesson from a visiting artist, and practicing the technical skills that allow the girls to travel in rope teams through crevassed areas. “At the end, we want to look at one landscape and see it through many lenses— as a mountaineer, assessing how to get from Point A to Point B, and what gear she’ll need; an artist, seeing color and texture; and a scientist, asking, how did these mountains come to be? Why is this rock different from that rock?” This interdisciplinary approach resonated with Emma Apitzsch, a 2017 Girls on Ice student who lives in Talkeetna, Alaska, and is training to be a bush pilot and mechanic. Emma reflected, “Before Girls on Ice, I had never stopped and really looked at something from an artistic perspective. Through our different activities, I got to explore new ideas and possibilities to interpret what I was seeing.” The place-based science curriculum at the core of Girls on Ice also changed Emma’s perspective. “Already, I look at a mountain, the trees, a small plant…anything! I look at it a slight differently. I think and observe the ground I stand on a little differently too. What will it all look like in hundreds of thousands of years? Where will all of this be?” she said. “Looking through a science lens has made me...

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