What Happens to Species Diversity as Glaciers Melt?
Published in July 2019, a study looked at the effects of melting glaciers on seafloor species diversity in Antarctica.
As glaciers melt, more sediment is released into the surrounding waters and can smother seafloor communities. As part of the same process, more icebergs are created which can scrape the bottom of the ocean, removing the top layers of sediment, known as soft sediment.
Soft sediment contains a great deal of life and plays an important role in marine ecosystems The study explains that it is one of the “key components of energy flow through food webs” and is important “in sedimentary processes especially nutrient and carbon cycling, waste breakdown and removal.”
The authors wrote that it was “the first study to comprehensively analyse the composition of Antarctic soft sediment metazoan communities across all size classes, from < 1 mm up to 10 cm, in two geographically distinct coves.”
The study found that “in contrast to findings from rocky substrata, there was no evidence of an effect of typical Antarctic stressors of iceberg scour and intense seasonality. As at other latitudes, organic content of the sediment was most strongly correlated with community structure, suggesting that increased sedimentation from run-off from melting glaciers may be the main climate change effect on these communities.”
Credit rating agency buys climate risk firm
A New York Times article explains the credit rating agency Moody’s purchase of Four Twenty Seven, a firm that measures climate risk:
“Sudden shocks such as floods, wildfires or storms can hurt businesses and send residents fleeing, taking away the tax revenue that governments use to pay their debts. And longer-term threats — such as rising seas or higher temperatures — can make those places less desirable to live in, hurting property values and, in turn, the amount raised by taxes.
Rating agencies translate those risks, along with more traditional factors such as a government’s cash flow and debt levels, into a credit rating, which communicates to investors the odds that a government will be unable to repay its bondholders. Lower ratings generally mean that borrowers need to offer investors a higher return to account for that risk.
Following a string of deadly hurricanes and wildfires in 2017, Moody’s, along with S&P Global and Fitch Ratings, issued reports warning state and local governments that their exposure to climate risk could affect their credit ratings.”
Alaskan glacier podcast
In a 25 minute podcast, Manasseh Franklin describes her experience following the water from a glacier in Alaska to the sea. She “wanted to make the melting of glaciers more real to people through her writing. So on an Alaskan rafting trip, she followed water to its source.”
As my year of research on glacier dynamics and water security in Chile came to a close in December 2018, I started searching for ways to put my newfound knowledge to good use while also soaking up the Patagonian summer. Through a bit of finesse and luck, I found a glacier education and guiding position for a polar expedition cruise company called One Ocean Expeditions. I felt like I was walking in a dream as I boarded an ice class cruise ship departing from Ushuaia, Argentina.
Through the five trips I worked on earlier this year, I had the great fortune to visit and interpret a myriad of glaciers from the shallow coves of the Antarctic Peninsula to the deep labyrinth of the Chilean fjords. Each glacier told a unique story, but a common theme emerged that links them all. While these massive, flowing systems may humble us with their power and enormity, they are deeply sensitive to their surroundings and profoundly affected by human-induced climate change.
There were four sites in my travels from the Antarctic Circle (66°33’S) north to Santiago, Chile (33°25’S) that best illustrated this duality for me.
Wilkinson and Murphy Glaciers,
Crystal Sound, Antarctica
The sun peaked over the horizon as we crossed into the Antarctic Circle and washed an orange light over the endless whiteness of the Stefan Ice Piedmont and Wilkinson and Murphy Glaciers. I couldn’t ask for a more majestic first glimpse of Antarctica.
Stefan is a modest size for an ice piedmont, a term to describe a low-lying expanse of ice that gradually slopes from the edge of a mountain to the sea. In comparison, the Wilkinson and Murphy Glacier complex is quite large, serving as an outlet for the Antarctic Peninsula Ice Shelf through a network of multiple glacial valleys that converge to tumble down to the sea.
waded through a bay of asymmetrical, peculiar icebergs that rivaled the size of
our eight-story ship. Unlike the more uniformed, tabular icebergs we later
encountered, which had neatly separated from ice shelves, these icebergs likely
calved off Wilkinson and Murphy or a neighboring tidewater glacier.
Crystal Sound set the stage for Antarctica as a dreamy, vast-beyond-comprehension, and complex continent of ice—a place that feels other-worldly until you realize these calving glaciers and massive melting icebergs feed the same ocean we all share.
Avalanche and Astudillo Glaciers, Paradise
Moving north, Paradise Harbor proved to be my favorite stop on each trip. It offers the best of the Antarctic Peninsula in mid-summer—calm and beautiful scenery, feeding humpback whales, porpoising penguins, and playful seals. We would start the day with a hike from the Almirante Brown Argentine base to a gentoo penguin colony and up to a bluff with a sweeping view of the massive Avalanche and Astudillo Glaciers.
One of my colleagues commented that in the seven years she has visited Paradise Harbor, she’s witnessed Astudillo Glacier recede noticeably. I’m yet to find an up-to-date study that could corroborate or rebut this observation, but it would be consistent with the behavior of the glacier in the late 20th century—displaying a frontal recession from 1973 to 1989 to the LIMA observations in the early 2000s.
our days were tranquil, I wondered what the collapse of the Larsen B Ice Shelf,
just over the ridge, felt like here and what the break-up of the even larger
Larsen C Ice Shelf will bring.
Serrano Glacier, Cordillera Darwin
Ice Field, Chile
Although they were connected until about 40 million years ago, the Antarctic Peninsula and southern tip of South America today feel like two separate worlds. The hardy, dwarfed vegetation of the Cordillera Darwin is a wash of green in comparison to the Antarctic landscape, and the glaciers are smaller, more active, and radiate a rich blue hue.
Serrano is a northern-facing glacier deep in the Agostini Fjord and outlet for the Cordillera Darwin Ice Field, the third largest expanse of ice in South America. On a sunny and wind-free morning, we maneuvered closer to Serrano’s face and marveled at a thick medial moraine that traced up to the convergence of two upper branches of the glacier.
The Serrano Glacier, like the vast majority of glaciers in the region, is losing mass. Between 2000 and 2011, its area thinned at an average rate of about 1.0±0.4 meters of water equivalent per year and, overall, the Ice Field lost an average of -3.9±1.5 gigatons of ice per year.
struck me about Serrano is how gorgeous, massive, and storied it is, while
remaining practically anonymous—located in a region that few have even heard
of, Serrano is rarely visited or studied.
Pío XI Glacier, Southern Patagonia
Ice Field, Chile
In contrast, Pío XI, also known as Brüggen Glacier, is one of the most famous glaciers in South America. At a whooping 1,300 square kilometers, it is about as large as Los Angeles and is the biggest glacier on the continent—and one of the only that is advancing.
Between 1945 and 1995, Pío XI advanced 10 kilometers at speeds of up to 50 meters per day, paving over 400-year-old trees and sealing off the upper section of the fjord, which brought about the formation of a lake. It has since slowed considerably, as warmer temperatures have caused more precipitation to fall as rain instead of snow and its primary flow path has shifted from the south terminus to the north.
Scientists surmise that Pío XI surged, while its neighbors continued retreating, possibly because of high snow accumulation in its abnormally large basin, fjord-glacier interactions, elevated water pressure beneath the glacier, changes in geothermal activity, or sediment build-up at its terminus.
a famous and peculiar glacier, I could barely contain my excitement as we
cruised into Eyre Fjord and watched the gargantuan, blue mass come into focus from
the upper deck. I trailed behind Australian glaciologist Ian Goodwin with his
black beret and sharp goatee as we walked along Pío XI’s wide southern terminal
moraine and searched for the source of a sediment-rich stream gushing out from
the bottom of the glacier.
XI was unlike any other glacier we’d seen—the water was saturated with sediment
and free of icebergs, the face was a modest height and sloped away from us, and
we observed no calving events that day. The preposterous amount of sediment and
continuous purge of meltwater begged a closer look. We scribbled notes and took
pictures to report back to colleagues and pondered how we could return with a
A cryosphere in crisis
The recent headlines in Greenland remind us the cryosphere is changing faster than we can grasp. Our modeling and monitoring is more accurate than ever, but the general public is just beginning to understand the complexity and urgency of the issue.
I found that these cruises offered a powerful platform to connect with folks from across the political spectrum through an immersive and emotional crash course in glaciology. I’m not yet sure how, but there must be a way we can create equally moving but more accessible and sustainable educational opportunities. As I reflect comfortably at home, Wilkinson and Murphy, Avalanche and Astudillo, Serrano, and Pío XI continue to flow.
A consensus estimate for the ice thickness distribution of all glaciers on Earth
From Nature Geoscience: “Projections of future glacier change, estimates of the available freshwater resources or assessments of potential sea-level rise all need glacier ice thickness to be accurately constrained. Previous estimates of global glacier volumes are mostly based on scaling relations between glacier area and volume, and only one study provides global-scale information on the ice thickness distribution of individual glaciers. Here we use an ensemble of up to five models to provide a consensus estimate for the ice thickness distribution of all the about 215,000 glaciers outside the Greenland and Antarctic ice sheets.”
A risk assessment of the area surrounding the Popocatépetl volcano
From Geofísica Internacional: “In the areas of highest risk, 20 towns in Puebla State, 8 in México State, and 2 in Morelos State were evacuated; in areas of intermediate risk, also were evacuated 5 towns in México State, 1 in Puebla State, and 2 in Morelos State. In addition, the San Buenaventura Nealtican community in Puebla was evacuated, because it was in the lahar flow path along the Huiloac ravine, which originates on the north side of the volcanic cone, at the glacier which potentially could be eroded and melted by pyroclastic flows. “
Degradation of macroalgal detritus in shallow coastal Antarctic sediments
From Limnology and Oceanography: “The western Antarctic Peninsula is one of the fastest warming areas on Earth (Ducklow et al. 2007). As a result, its glaciers are melting and retreating at unprecedented rates (Rückamp et al. 2011; Cook et al. 2016). The retreat of glaciers opens up new habitat for marine benthic organisms (e.g., Lagger et al. 2018), such as sublittoral rocky substrates that are increasingly colonized by macroalgae (Quartino et al. 2013; Mystikou et al. 2014; Campana et al. 2018). Macroalgal communities play an important role in the Antarctic coastal ecosystem. They dominate shallow benthic communities on hard substrates along the western Antarctic Peninsula, often covering > 80% of the bottom, with standing biomass levels comparable to temperate kelp forests (Wiencke and Amsler 2012). A global average of 82% of the local primary production from kelp is estimated to enter the detrital food web where it can be exported to adjacent communities (Krumhansl and Scheibling 2012).”
Amid Antarctica’s vast stretches of glittering white snow and ethereal blue glacier ice is the famous Blood Falls. Situated at the terminus of Taylor Glacier in the McMurdo Dry Valleys, Blood Falls, which is an iron-rich, hypersaline discharge, spews bold streaks of bright-red brine from within the glacier out onto the ice-covered surface of Lake Bonney.
Australian geologistGriffith Taylor was the first explorer to happen upon Blood Falls in 1911, during one of the earliest Antarctic expeditions. At the time, Taylor (incorrectly) attributed the color to the presence of red algae. The cause of this color was shrouded in mystery for nearly a century, but we now know that the iron-rich liquid turns red when it breaches the surface and oxidizes––the same process that gives iron a reddish hue when it rusts.
The discharge from Blood Falls is the subject of a newstudy, published in the Journal of Geophysical Research: Biogeosciences, researchers sought to discern the origin, chemical composition, and life-sustaining capabilities of this subglacial brine. Lead author W. Berry Lyons of The Ohio State University and his co-researchersdetermined that the brine “is of marine origin that has been extensively altered by rock-water interactions.”
Researchers used to believe that to be that Taylor Glacier was frozen solid from the surface to its bed. But as measuring techniques have advanced over time, scientists have been able to detect huge amounts of hypersaline liquid water at temperatures that are below freezing underneath the glacier. The large quantities of salt in hypersaline water enable the water to remain in liquid form, even below zero degrees Celsius.
Seeking to expand on this recent discovery, Lyons and his co-researchers conducted the first direct sampling of brine from Taylor Glacier using the IceMole. The IceMole is an autonomous research probe that clears a path by melting the ice that surrounds it, collecting samples along the way. In thisstudy, the researchers sent the IceMole through 17 meters of ice to reach the brine beneath Taylor Glacier.
The brine samples were analyzed to obtain information on its geochemical makeup, including ion concentrations, salinity, and other dissolved solids. Based on the observed concentrations of dissolved nitrogen, phosphorus, and carbon, the researchers concluded that Taylor Glacier’s subglacial environment has, along with high iron and sulfate concentrations, active microbiological processes––in other words, the environment could support life.
To determine the origin and evolution of Taylor Glacier’s subglacial brine, Lyons and his co-researchers pondered other studies’ conclusions in comparison to their results. They decided the most plausible explanation was that the subglacial brine came from an ancient time period when Taylor Valley was likely flooded by seawater, though they did not settle on an exact time estimate.
In addition, they found that the brine’s chemical composition was much different than that of modern seawater. This suggested that as the brine was transported throughout the glacial environment over time, weathering contributed to significant alterations in the chemical composition of the water.
Thisstudy provides insights not only for subglacial environments on Earth but also potentially to other bodies within our solar system. Seven bodies, including Europa (one of Jupiter’s moons), Enceladus and Titan (two of Saturn’s moons), Pluto, and Mars are thought to harbor sub-cryospheric oceans.
Lyons and his co-researchers concluded that this subglacial brine environment likely is conducive to life. The ability of sub-cryospheric environments such as this one to support life on Earth hints at an increased possibility of finding life in similar environments elsewhere in our solar system.
This week’s Roundup covers discovery of what causes the reddish tint of “Blood Falls,” the Taylor Glacier’s terminus in Antarctica, a bill passed by the US Senate that could protect glaciers in North Cascades National Park, and ICIMOD’s newly published Hindu Kush Himalaya Assessment.
Scientists Determine the Geochemistry of Antarctica’s Blood Falls
From Journal of Geophysical Research: Geosciences: “Blood Falls is a hypersaline, iron‐rich discharge at the terminus of the Taylor Glacier in the McMurdo Dry Valleys, Antarctica…Our results provide strong evidence that the original source of solutes in the brine was ancient seawater, which has been modified with the addition of chemical weathering products.”
Good News for Glaciers in North Cascades National Park
From the National Parks Traveler: “Strong bipartisan support in the U.S. Senate has reauthorized the Land and Water Conservation Fund, protected Yellowstone and North Cascades national parks from mining on their doorsteps, designated some 1.3 million acres of wilderness, and called for a study into potential units of the National Park System, though the House of Representatives still needs to take up the measure.”
Assessing the Value of the Hindu Kush Himalaya
From ICIMOD: “This assessment report establishes the value of the Hindu Kush Himalaya (HKH) for the 240 million hill and mountain people across the eight countries sharing the region, for the 1.65 billion people in the river basins downstream, and ultimately for the world. Yet, the region and its people face a range of old and new challenges moving forward, with climate change, globalization, movement of people, conflict and environmental degradation. At the same time, we also see incredible potential to meet these challenges in a sustainable manner.”
Collapsing Glaciers in The Himalaya–Hindu Kush mountain ranges & the Tibetan Plateau
From Nature: “Tibetan communities are dealing with the impacts of collapsing glaciers. In October 2018, debris dammed the Yarlung Tsangpo River, which forms the headwater of the Brahmaputra, threatening areas as far afield as Bangladesh with flooding.”
From Ecological Applications: ” In this study, we describe contrasting responses to an apparent regime shift [in food particle size] of two very different benthic communities in McMurdo Sound, Antarctica. We compared species-specific patterns of benthic invertebrate abundance and size between the west (low productivity) and east (higher productivity) sides of McMurdo Sound across multiple decades.”
Read more about the changes to benthic invertebrates in Antarctica here.
Resilient Mountain Solutions in the Hindu Kush Himalaya
From UNFCCC: “Research at ICIMOD has revealed that temperatures in the mountains have increased significantly faster than the global average, and are projected to increase by 1–2°C on average by 2050. Precipitation patterns and water availability are likely to change.”
Read more about Resilient Mountain Solutions such as vulnerability reduction and improved ecosystem services here.
From Proceedings of the National Academy of Sciences: Antarctica’s ice is melting at an accelerating pace—six times the melt rate four decades ago—and that could have significant consequences for coastal communities around the world. The Antarctic shed 40 billion tons of ice each year between 1979 and 1989. But researchers say that the southern continent has been shedding 252 billion tons of ice each year since 2009.
“I don’t want to be alarmist,” Eric Rignot, an Earth systems scientist for both the University of California, Irvine, and NASA, who led the work, toldThe Washington Post. “The places undergoing changes in Antarctica are not limited to just a couple places,” said Rignot. “They seem to be more extensive than what we thought. That, to me, seems to be reason for concern.”
From Inspiring Girls Expeditions: Offering free, wilderness excursions for high school-aged girls, Inspiring Girls Expeditions aims to foster curiosity about the natural world and methods of scientific inquiry. Since 1999 University of Alaska, Fairbanks glaciologist Erin Pettit has led over a dozen “Girls on Ice” trips to Washington’s South Cascade Glacier.
Pettit founded the program because “I wanted to share the inspiration, curiosity, and excitement of using science to learn and explore the mountains. In turn, the girls have taught me about the dreams, and challenges, and amazing variation of lives and experiences for girls from all different communities and cultures across the world.”
Upcoming Girls on Ice expeditions include trips to the Gulkana Glacier in Alaska, Washington’s Mount Baker, the Asulkan Valley in British Columbia, and the Findelen Glacier in Switzerland.
Find out more about Inspiring Girls Expeditions here.
A New Tool for Modeling Glacier Flow
From The Journal of Chemical Physics: Bo Persson, a theoretical physicist at the Jülich Research Center in Germany, has developed an improved model of glacier flow. Persson said his model improves understanding of the cavities that form between ice and bedrock and how water fills these cavities and becomes pressurized.
Persson’s past work has focused on rubber friction and adhesion. “I could take knowledge I have gained during maybe 10 or 15 years of studies of other friction and quickly apply it to the glacier friction problem,” he told the CBC.
The model could help improve estimates of how much glacier melt is contributing to sea level rise around the world.
Scientifically, we know glaciers as slow-moving bodies or rivers of ice, formed on mountaintops and near the poles by repeated processes of snow accumulation and compaction over lengthy periods of time. Through science we attempt to maintain an objective distance from the world’s glaciers, positing them as objects unconnected and detached from human experience. However, humans give meaning and purpose to glacial environments. We do this by attaching symbols, metaphors and analogies to the natural world in our literature and observations as we make sense of environments outside ourselves.
This GlacierHub series on “glaciers in the symbolic domain” began with “The Myth of Glacial Safety,” which examined society’s propensity to attach perceived safety to unstable glacial environments. Next, we considered the influence of glacial environments on human relationships in Journey Over Gobrin Glacier: Le Guin, Environmentalism and Science Fiction. Today’s article spotlights author Kim Stanley Robinson’s 1997 novel, “Antarctica,” which explores how humans utilize glacial environments to escape from modern-day living and connect to past and future, transcending their own lifetimes.
Robinson is a revered American science fiction writer, best known for his “Mars Trilogy” chronicling the settlement and eventual terraforming of the planet Mars through powerful personal relationships and perspectives. The novel ultimately won Robinson a Nebula Award (1993) and Hugo and Locus Awards (1994 and 1997). Mars Trilogy pre-dates and subsequently foregrounds his novel “Antarctica,” which shifts the focus from alien worlds to seemingly alien worlds on Earth. The main themes found in his work are preservation of nature, ecology, sustainability, environmental justice and climate change.
On its surface, “Antarctica” is a novel of societal progress and scientific exploration. Its three main characters, X, an American college graduate named for being extra large; Valerie Kenning, a tour guide; and Wade Norton, a politician’s assistant, take turns telling the story from their own perspective.
X, who arrived in Antarctica for adventure and exploration, is the first character to develop a unique relationship with the glaciers around him. His frequent diversions from his group, often alone, take him both under and atop many of Antarctica’s real glaciers featured in the novel.
“X’s nighttime ascent of the Skelton [glacier], through the spectacular peaks of the Royal Society Range, had been the most exciting part of his trip so far, crunching up causeway after causeway of crushed ice concrete, with serac fields like dim shattered Manhattans passing right to left,” the text reads.
The Skelton glacier, one of X’s preferred travel routes, is also historically the glacier chosen as the passageway for mountaineer Vivian Fuchs’ legendary first overland crossing of the continent in 1957. X’s excursion up the glacier also featured “seracs,” which are columns of glacial ice formed by intersecting crevasses on a glacier. Because of their instability and propensity to collapse, seracs are typically viewed as dangers to mountaineers; however, X is unafraid of their presence and likens them to a “shattered Manhattan.” This representation of a glacial phenomenon as a destroyed city makes X feel as though he has escaped the man-made “built” world and connects him to a time, presumably in the future, when cities will no longer be a dominant feature in the geography of the planet.
The purpose for Wade’s Antarctica travels were to evaluate political conditions for the renewal of the Antarctic Treaty System for Wade’s politician employer, a U.S. Senator. During intense moments in the novel, Wade often reflected on the glaciers around him. “To distract himself he looked at the brilliant white glacier pouring down from the head of the valley. It was the middle of the night, and yet the mass of ice was glowing in the sunlight like an intrusion from some brighter dimension,” Robinson writes. In this moment the glacier allows Wade to step out of time. Wade’s reference to the glacier being from “another dimension” helps him experience a time that existed before him, and will continue to exist after his own lifetime. The glacier is a welcome distraction and escape from the stresses of his relationships and modern-day living.
The specific glacier distracting Wade in the narrative is the Wright Upper glacier, a place known as “the labyrinth.” This particular glacier features an ice flow called the Airdevronsix Falls that is buttressed by harsh, dry rock peaks. The juxtaposition between the crystalline falls and brown rock peaks is striking.
While the narratives in the novel focus on the work and relationships of each of the characters, many scholars agree that the real main character is the frozen, inhospitable environment of Antarctica itself, including the glaciers that the characters frequently travel through, on and around.
In their quest for new knowledge as well as scientific and political breakthroughs in the frozen and inhospitable landscape, these characters are given an escape from their worldly pursuits through their experiences with the glaciers. Robinson purposefully utilizes Antarctica’s real glaciers, history and topography in his novel to give readers the same experience. The glaciers in the novel symbolize how each character transcends their current time. Robinson’s literature uses these symbols to aid people in making sense of the world around them.
For several years, researchers have worked to determine how life can be sustained in extraterrestrial space, known for conditions of extreme heat and cold. A recent study in the journal Extremophiles, conducted on Deception Island in Antarctica, provides answers to some of these questions.
At Deception Island, both volcanoes and glaciers lie in close proximity, creating regions of prominent temperature differences over a short distance. The extreme conditions on the island range from 98 to 0 degrees Celsius due to the presence of active fumaroles (openings near the volcano), where the temperatures reach values of 100 degrees Celsius, and glaciers, where temperatures drop to 0 degrees Celsius. The close proximity of volcanoes and glaciers makes Deception Island an interesting analogue for extraterrestrial environments, including Mars’s extinct volcanoes and Enceladus’s cryovolcanoes.
This polar location allowed researchers to recover microorganisms that have the ability to survive under very hot conditions beyond their growing range of temperature. The study explored the microorganisms surviving in these conditions and tested their survival potential in astrobiological conditions.
To isolate the microorganisms surviving in these extreme environments, the scientists collected sediment samples from the volcano on Deception Island during the XXXII Brazilian Antarctic Expedition from December 2013 to January 2014 at the geothermally active sites of Fumarole Bay and Whalers Bay.
Through DNA-sequencing techniques, scientists estimated the total number of bacterial cells in the sediment. To isolate microbes that have the ability to survive in extreme conditions, the samples were incubated in two different temperatures, 4 degrees Celsius and 60 degrees Celsius. The samples were allowed to grow for about two weeks. A total of 147 colonies were successfully obtained from these procedures, and they were subjected to further molecular analyses to determine the species and the genera of the microorganisms.
In addition, the samples were subjected to ultraviolet radiation that is present on Mars, called UV-C radiation. UV-C radiation, although not present on Earth, composes a significant proportion of UV spectra on the Martian surface, due to the rarified atmosphere of the planet.
Scientists from the study found that the microorganisms were able to survive these conditions despite the fact that these range of temperatures were beyond the range in which they normally grow. The study also found that these microorganisms adapted to surviving under these temperatures by forming spores around their membranes, which enabled them to resist the extreme range of temperatures. These structures suggested to the researchers that there could be a similar adaptation strategy to enable the survival of microbial life on Martian surfaces.
The study provided interesting insights into strategies deployed by microorganisms to survive in conditions that resemble the Martian surface. The initial data from the study suggest the thermophiles isolated by the researchers have the potential to be further explored in astrobiological studies.
Sruti Devendran holds a Master’s degree in Climate and Society from Columbia University. She did her undergraduate degree in biotechnology in India. She is curious about the potential possibility of life in extraterrestrial space. She enjoys writing and cares about issues affecting low income communities impacted by climate change.
From Nature.com: “An increased mass discharge (53 ± 14 Gt yr−1) was found in the East Indian Ocean sector since 2008 due to unexpected widespread glacial acceleration in Wilkes Land, East Antarctica, while the other five oceanic sectors did not exhibit significant changes. However, present-day increased mass loss was found by previous studies predominantly in West Antarctica and the Antarctic Peninsula. The newly discovered increased mass loss in Wilkes Land suggests that the ocean heat flux may already be influencing ice dynamics in the marine-based sector of the East Antarctic ice sheet (EAIS).”
Zinke Seeks to Restore Glacier National Park’s Sperry Chalet
From Missoulian: “As part of a wide-ranging press conference here Saturday, Zinke said public comments overwhelmingly support rebuilding the popular backcountry chalet’s dormitory, burned in last summer’s Sprague Fire, as close as possible to its original state while making some upgrades. He proposes using a mix of public and private dollars to complete the work, adding that he is prepared to commit ‘whatever it takes in federal funding to restore the structure.”
Black Flies and Interactions with Climate Phenomena
From ScienceDirect: “The lack of simuliids near the glacier might be associated with the low temperature, low discharge, and reduced particulate organic matter of the meltwater. Our results are consistent with studies of simuliids in other mountains of Colombia, which document a lack of Simulium species above the páramo (i.e., in the super páramo) (Muñoz and Miranda, 2000)… Our results emphasize the dynamic nature of simuliid communities over space and time. Studies of how simuliids respond to El Niño and La Niña can provide a window into the effects of global climate change (Finn and Adler, 2006)”
Find out more about this disease transmitting vector and its environmental stimuli here.
In a bid to preserve ice cores and valuable climate information from some of the world’s most endangered glaciers, scientists are creating a global ice archive sanctuary in Antarctica. The Ice Memory project is being led by the Université Grenoble Alpes Foundation.
From Mont Blanc Massif’s Col du Dôme glacier to the Illimani glacier in Bolivia, over 400 ice cores have been retrieved to be preserved in the ice bunker.
To learn more about Ice Memory, see the video below from the Université Grenoble Alpes Foundation:
Glaciers around the world are making headlines for their rapid retreat due to warming. Unlike some of these glaciers, however, dry valley glaciers, while accumulating only about 10 cm of snow annually, are neither retreating nor warming. Sarah Fortner, a geochemistry professor at Wittenberg University in Ohio, examined the meltwater of Canada Glacier, a dry valley glacier located in the Taylor Valley of Antarctica, and published a paper focused on two of its proglacial streams, Anderson Creek and Canada Stream.
Melting of glaciers develops an important part of a glacier’s anatomy known as “supraglacial streams,” which are conduits of water on top of glaciers. These supraglacial streams often become a source of water for “proglacial streams,” like the Anderson Creek and Canada Stream, narrow channels of rivers that issue from glaciers supply water to lakes located below the glaciers.
Fortner studied the meltwater of Canada Glacier during the 2001 to 2002 austral summer in the southern hemisphere (from November to March) and the contribution of the proglacial stream and glacial surface to water in Lake Hoare, which is located in front of Canada Glacier.
In her study, Fortner determines the crucial role of the wind in redistributing the geochemistry of the glacial surface as well as the two proglacial streams. By looking at the geochemistry of the two proglacial streams and the role of the wind in bringing valley sediments to the supraglacial and ultimately proglacial streams, Fortner found that the glaciers that contributed to the proglacial lakes are not dilute like glacier snow.
Contrary to expectations, the chemistry between the two streams was quite different. “While they are roughly five miles apart, they were very different,” she told GlacierHub. “Located on the east side of the glacier, Canada Stream was teaming with life, with multiple mosses, lichen, algae, and invertebrates. If you were to press your hand into these, it would feel like a sponge. On the west side of the glacier, Anderson Creek looks barren in comparison. There is life in the stream, but not as abundant or diverse as the Canada Stream.”
In an attempt to find the source of the difference, Fortner and a team of scientists sampled water from supraglacial channels with high discharge for chemical analysis. Through this analysis, Fortner aimed to map the evolution of the chemicals in the meltwater at Canada Glacier from unmelted glacier snow to supraglacial streams to proglacial streams and finally to Lake Hoare located in front of the glacier.
With the chemical mass balance analysis of the samples from the glacier, Fortner first wanted to see whether the chemical composition of the supraglacial stream would be diluted like the unmelted glacier snow, their primary precipitation. According to Fortner, unmelted glacier snow would naturally be very dilute, with a low concentration of any chemical solute, and we would expect the same level of chemical concentration from the supraglacial streams, located on top of the glacier body itself and created as a result of glacier snow melting. However, she found that supraglacial streams were rich in major ions like calcium, sodium, and sulfate.
“This begins to highlight the importance of wind-blown sediment as control of water chemistry in these Antarctic ecosystems,” Fortner said.
In her paper, she explains that the strong west to east Föhn wind (Foehn wind), a parcel of dry and warm air moving down the lee (downwind side) of the mountain, brought sediments from the floor of Taylor Valley, abundant with carbonate ( CO3(2-)) and gypsum (CaH4O6S) minerals, which are the sources of the high calcium (Ca2+) and sulfate ion (SO2-4) found in the supraglacial streams. In short, the wind delivered sediment that influenced the chemistry of the streams on the surface of the glacier.
“Both sides of the valley floor contributed to the sediment received on the glacier surface which explained major chemical differences found in supraglacial and proglacial streams versus the original unmelted snow. It is also clear that the Föhn wind coming off of the ice sheet had the greatest influence on depositing chemistry,” Fortner explained.
Furthermore, the west to the east direction of the wind causes a difference in chemical composition between the proglacial streams in the western and eastern sides of Canada Glacier, preferentially depositing more sulfate in the western proglacial streams (Anderson Creek) than in the eastern proglacial streams (Canada Stream).
“As a result of the west to east wind, supraglacial streams flowing into Anderson Creek have much higher concentrations of both calcium and sulfate than supraglacial streams flowing into Canada Stream,” Fortner explained.
The chemical deliveries from the stream channel to the proglacial lake is crucial to examine, as Anderson Creek contributes over 40 percent of the water to Lake Hoare, the final recipient of the meltwater from Canada Glacier, during the low-melt season. However, Fortner said it is just as important to examine the chemical deliveries from the glacial surface (direct runoff).
“While one would think streams would deliver far more chemistry, as glaciers and their direct runoff are typically dilute, glacier surface can be just as important source of chemistry because of the low accumulation and wind delivered sediment,” she added.
Dry valley glaciers are unique in that the glacier surface is an important contributor of chemistry to downstream ecosystems. Unlike many other glaciers, it isn’t just about chemistry from stream channels, but also about glacier surfaces. If more melt continues in response to the wind, this could result in potential changes in the chemical delivery into Lake Hoare. Furthermore, such changes can extend to the continental outline of Antarctica into Ross Sea, the southern extension of the Pacific Ocean.