At Glacier’s End: Protecting Glacial Rivers in Iceland
“Page after page of curving colorful rivers delight the eye in At Glacier’s End, a recently published book about Iceland’s glacial river systems. The images that lie behind its cover were created by Chris Burkard, a photographer and explorer, and the more than 8,000 words that tell their story were penned by Matt McDonald, a storyteller and traveller.”
“Our main goal with the book was to advocate for Iceland’s national parks and to try to create a voice for them from a visual perspective,” Burkard said in an interview with GlacierHub. “In Iceland, it’s really surprising, many politicians who are the decision-makers haven’t had a chance to actually see [these places] because they are far away and really hard to access.”
Seabirds Find New Ways to Forage in a Changing Arctic
“On Arctic landmasses, valley glaciers––formally known as tidewater glaciers––run all the way to the ocean, where cloudy plumes from their discharge create the perfect foraging habitat for seabirds. Researchers found some birds are reliant upon the turbid, subglacial freshwater discharge, which breaks apart icebergs and forms a column of freshwater foraging ground at the glacier’s edge, while others prefer to forage near the broken sea ice where water is less turbid…In 2019, Bungo Nishizawa and associates published a study in the ICES Journal of Marine Science that investigated the effects of subglacial meltwater on two assemblages of seabirds in northwestern Greenland.”
Read the full story by GlacierHub writer Audrey Ramming here.
A First-ever Look at Ice Stream Formation
In this week’s Video of the Week, the world gets its first-ever look at ice stream formation. The video, which was published on the American Geophysical Union’s (AGU) YouTube channel on December 17, tracks the rapid movement of the Vavilov Ice Cap, in the high Russian Arctic, from summer 2015 to summer 2018. In the video the glacier’s speed is color-coded by meters per day of movement in what scientists believe is the first documented transition of a glacial surge to a longer-lasting flow known as an ice stream.
In this week’s Video of the Week, the world gets its first-ever look at ice stream formation. The video, which was published on the American Geophysical Union’s (AGU) YouTube channel on December 17, tracks the rapid movement of the Vavilov Ice Cap, in the high Russian Arctic, from summer 2015 to summer 2018.
In the video the glacier’s speed is color-coded by meters per day of movement in what scientists believe is the first documented transition of a glacial surge to a longer-lasting flow known as an ice stream.
“Ice streams and glacial surges were believed to be separate phenomena driven by different mechanisms,” the AGU wrote in the caption. “But if the authors of the new study are correct, glacial surges could instead be an early stage of an ice stream.”
NASA documented the surge in an April 2019 story “A Surprising Surge at Vavilov Ice Cap.” Glaciologists took notice of the glacier’s abberant behavior in 2013, when it suddenly sprang forward, an unusual development for a cold-based glacier, which tend to move slowly. The finding startled glaciologists because if the Vavilov Ice Cap’s outlet glacier can suddenly transition from stable ice––to ice stream––then so can other ice caps, which would upend sea level rise predictions globally.
“The fact that an apparently stable, cold-based glacier suddenly went from moving 20 meters per year to 20 meters per day was extremely unusual, perhaps unprecedented,” University of Colorado Boulder glaciologist Michael Willistold NASA in April 2019. “The numbers here are simply nuts. Before this happened, as far as I knew, cold-based glaciers simply didn’t do that…couldn’t do that.”
Whyjay Zheng is a Ph.D. candidate at Cornell University and the lead author of the new study. “If you look at the satellite images, it seems like the entire west wing of the ice cap is just dumping into the sea,” Zheng said. “No one has ever seen this before.”
From Nature: “The sensitivity of the Northeast Greenland Ice Stream (NEGIS) to prolonged warm periods is largely unknown and geological records documenting such long-term changes are needed to place current observations in perspective. Using cosmogenic surface exposure and radiocarbon ages, the magnitude of NEGIS margin fluctuations over the last 45 kyr (thousand years) was determined. The NEGIS experienced slow early Holocene ice-margin retreat of 30–40 meters per year, likely as a result of the buttressing effect of sea-ice or shelf-ice. This retreat was smaller than present for approximately half of the last ~45 kyr and is susceptible to subtle changes in climate, which has implications for future stability of this ice stream.”
Discover more about ice stream and melting in Greenland here.
Sea Ice, Blue Carbon and Antarctic Climate Feedbacks
From The Royal Society: “Sea ice, including icebergs, has a complex relationship with the carbon held within animals (blue carbon) in the polar regions. Sea-ice losses around West Antarctica’s continental shelf generate longer phytoplankton blooms (less sea ice increases phytoplankton blooms, benthic growth, seabed carbon and sequestration) but also make it a hotspot for coastal iceberg disturbance. Significant benthic communities establish where ice shelves have disintegrated (giant icebergs calving), and rapidly grow to accumulate blue carbon storage. When 5000 km2 giant icebergs calve, we estimate that they generate approximately 106 tonnes of immobilized zoobenthic carbon per year (t C yr−1).”
Read more about the physical, chemical and biological processes of carbon sequestration here.
Analysis of Mt. Kenya’s Glacial Recession
From the American Journal of Environmental Science and Engineering: “In a bid to discover what has been causing the retreat of glaciers of Mount Kenya, Optical Landsat data for 1984 to 2017 and climatic data of the same years were used. Glaciers and forest coverage were extracted from Landsat images and its thermal band was used to extract temperature data. Correlation with the respective year’s climatic data and forest cover area were done to justify the assumption that the shrinkage in the glaciers coverage has been caused by changes in climate and/or deforestation… Mt Kenya glaciers are likely to have still completely disappeared by the year 2100.”
Explore more about the modelling of Mount Kenya’s glaciers here.