East Antarctica’s Totten Glacier has got some amazing social media presence. The Twitter account ‘Totten Glacier’ provides updates on relevant glacier news, while also offering some punny first-person commentary, adding a playful and refreshing spin to climate change research.
The account refers to the glacier as “old timer” and “sleeping giant”, as Totten is one of the biggest glaciers in the region. The glacier is so massive that it holds enough ice to raise global sea levels by about 3 meters.
According to NASA Jet Propulsion Laboratory, East Antarctica is relatively stable compared to the rapid melting in the western portion. However ice loss in the region has been substantial in the recent years.
In a recent story by Phys.org, a study obtaining data through new satellites reported significant ice loss from the Totten Glacier region. Approximately 1.4 billion tons of water have been lost in the last decade. Scientists from the study believe this to be just the beginning of serious change to the ice sheet.
Click below to check out a time lapse video by Google Earth demonstrating the recession at the foot of the glacier since 1984.
Researchers have generally thought that the East Antarctic Ice sheet has remained relatively stable despite global warming. But this is not the case, according to a recent study published in Science Advances. Chad Greene and a team of researchers discovered that the Totten, the largest glacier in East Antarctica, is melting. Shockingly, if the Totten Glacier were to melt entirely, it could raise sea levels by 11 feet.
“For the past decade, my research group at the University of Texas Institute for Geophysics has flown airborne campaigns over Totten to characterize its sensitivities, because Totten drains a massive portion of the East Antarctic Ice Sheet, about 550,000 km2, or ~3.5 m sea level rise in a complete collapse scenario,” Greene told Glacierhub. “That’s about as much ice as all the rapidly-changing glaciers of West Antarctica combined.”
The team’s project to study the Totten was a collaboration between the University of Texas at Austin, the University of Tasmania, and the Antarctic Climate and Ecosystems Cooperative Research Centre. Fernando Paolo, another member of the team, has shown that for long-term observations, Totten clearly thickens and thins on an interannual basis. So, the outstanding question was, what causes these interannual changes? What force is powerful enough to affect this massive system?
Using satellite data from 2001 to 2006, the researchers noted the increased movement of the Totten Ice Shelf toward the ocean. The ice shelf represents the floating portion of the glacier. In a pervious interview, Greene describes this phenomenon as “pancake batter that’s piled up and spreads toward the edges under its own weight.” Melting, whether from the surface or the bottom in contact with the ocean, tends to thin the ice sheet and increase the rate of flow outward.
This increased melt is also confirmed by the International Collaboration for Exploration of the Cryosphere through Aerogeophysical Profiling (ICECAP) Project, a collaboration between U.S., British and Australian Antarctic researchers that has been mapping the East Antarctic ice sheet. They have identified an area near Totten Glacier that is thinning with lowering surface heights at a rate of approximately 2m per year.
“Many forces act on Totten. We used satellite images to track Totten’s movements and found that on the interannual timescale, variability in glacier speed is influenced primarily by winds over the ocean nearby,” Greene told Glacierhub. When winds over the Southern Ocean intensify, warm water is pulled up from the deep ocean onto the continental shelf, creating the hot spot. “It’s like when you blow across a hot bowl of soup and little bits of noodles from the bottom begin to swirl around and rise to the top,” he added. This comparison suggests the dynamic nature of the thermocline, which refers to the region under water where temperature changes more rapidly with depth. The wind-driven upwelling raises the thermocline on the continental shelf and dunks the underside of Totten Ice Shelf in a warm water bath.
The wind drives the thermocline, bringing warm water toward the coast of the Totten Glacier, and circulates below through submarine canyons, causing it to melt from below. “The temperature difference experienced by a parcel of ice that’s suddenly exposed to this warm water is only a couple of degrees Celsius, but remember that bit of ice may be more accustomed to water that’s just 0.2 degrees above freezing–so a 2 degrees shock is about a 10 fold increase in melting power,” Greene said. This kickstarts a positive feedback mechanism that is self-reinforcing. More inland ice is exposed to the warm waters when the coastal layers of ice melt, and when these landlocked ice drain into the ocean, sea-level rise is certain.
Greene thinks of the Totten Glacier as “the sleeping giant because it’s huge and has been seen as insensitive to changes in its environment.” However, his team’s findings have shed light on what has caused the Totten’s rates of melting to vary over the years. With climate change expected to intensify the winds over the Southern Ocean in the next 100 years, the Totten Glacier will likely be impacted. This is groundbreaking news, since people often relate melting glaciers to increases in air or ocean temperatures, when, in fact, winds are actually sufficient.
“Some basal melt is a healthy part of a steady-state mass balance for Totten, so observations of melt are not shocking or cause for alarm,” Greene told GlacierHub. However, he added that his team showed an interesting sensitivity that changes in wind over the ocean get transmitted to the ice sheet. Greenhouse gases such as carbon dioxide have amplifying effects on Antarctic winds, deciding the fate of glaciers just by deciding the movement of warm water. “Of course, that has a gloom-and-doom component, but it’s also an interesting scientific curiosity–now we see how CO2 can lead to sea level rise without warming up the air and melting ice from above, and without even warming up the ocean, but just by moving heat around within the ocean,” he said.
What is the melting of just another glacier? If it is the Totten Glacier, it could mean another 11 feet of sea level increase.
From CBC News: “Kluane MLA Wade Istchenko says receding water levels on Kluane Lake are posing a problem for his constituents — and he wants the government to respond. The lake level first dropped last year, after the Kaskawulsh Glacier retreated so much that its meltwater abruptly switched direction, away from Kluane Lake. Researchers have blamed climate change for the geologic phenomenon referred to as ‘river piracy’.”
You can read more about how Istchenko proposes the legislature respond here.
Spillway Lake in Nepal Deepens
From Water: “Since the 1950s, many debris-covered glaciers in the Nepalese Himalaya have developed large terminal moraine-dammed supraglacial lakes, which grow through expansion and deepening on the surface of a glacier. As temperatures continue to rise and lakes continue to grow in area and volume, they pose a flooding risk to the Sherpa villages down-valley.”
Learn more about how the Ngozumpa Glacier’s terminal lake is growing here.
Melting an Ice Sheet from Below
From Nature: “Because the East Antarctic Ice Sheet seems so cold and isolated, researchers thought that it had been stable in the past and was unlikely to change in the future — a stark contrast to the much smaller West Antarctic Ice Sheet, which has raised alarms because many of its glaciers are rapidly retreating. In the past few years, however, “almost everything we thought we knew about East Antarctica has turned out to be wrong”, says Tas van Ommen, a glaciologist at the Australian Antarctic Division in Kingston, near Hobart. By flying across the continent on planes with instruments that probe beneath the ice, his team found that a large fraction of East Antarctica is well below sea level, which makes it more vulnerable to the warming ocean than previously thought. The researchers also uncovered clues that the massive Totten glacier, which holds about as much ice as West Antarctica, has repeatedly shrunk and grown in the past — another sign that it could retreat in the future.”
Read more about uncertainty in the East Antarctic here.
From Nature: “On a glorious January morning in 2015, the Australian icebreaker RSV Aurora Australis was losing a battle off the coast of East Antarctica. For days, the ship had been trying to push through heavy sea ice… Then the weather came to the rescue, with a wind change that blew the ice away from the shore, opening a path through the pack… Rintoul and his team were the first scientists to reach the Totten Ice Shelf — a vast floating ice ledge that fronts the largest glacier in East Antarctica… The team had to work fast before the ice closed again and blocked any escape. For more than 12 hours, Rintoul and his colleagues carried on non-stop, probing the temperature and salinity of the water, the speed and direction of ocean currents as well as the shape and depth of the ocean floor… These first direct observations confirmed a fear that researchers had long harboured… East Antarctica is well below sea level, which makes it more vulnerable to the warming ocean than previously thought.”
From Ecography: “The Antarctic Peninsula is among the places on Earth that registered major warming in the last 60 years… The loss of sea-bed ice coverage, on the one hand has been affecting benthic assemblages, but on the other it is opening up new areas for benthic colonization. Potter Cove (South Shetland Islands) offered the opportunity of assessing both processes. We recently reported a sudden shift of benthic assemblages related to increased sedimentation rates caused by glacier retreat. This glacier retreat also uncovered a new island that presents a natural experiment to study Antarctic benthic colonization and succession… Under the current scenario of climate change, these results acquire high relevance as they suggest a two-fold effect of the Antarctic Peninsula warming: the environmental shifts that threaten coastal ecosystems, and also the opening up of new areas for colonization that may occur at a previously unimagined speed.
From The Telegraph: “President Vladimir Putin on Wednesday visited an Arctic archipelago, part of Russia’s efforts to reaffirm its foothold in the oil-rich region. On a tour of the Franz Josef Land archipelago, a sprawling collection of islands where the Russian military has recently built a new runway and worked to open a permanent base, Mr Putin emphasized the need to protect Russia’s economic and security interests in the Arctic… During the visit, Putin inspected a cavity in a glacier that scientists use to study permafrost. He also spoke with environmental experts who have worked to clean the area of Soviet-era debris.”
From adn.com: “Matanuska Glacier is the most user-friendly glacier in Alaska — one of few major ice sheets in the world that visitors can drive to and explore on foot. The glacier sits along a scenic stretch of the Glenn Highway about two hours from Anchorage, a frozen river sprawling almost 30 miles from the 13,000-foot heights of the Chugach Mountains to a toe hundreds of feet deep and miles wide that offers unique glimpses of usually buried formations. The only road-accessible route to the ice is through property owned by Matanuska Glacier Park LLC… Before November, a tour was just one option for glacier-goers who wanted to spend several hours with a guide on a trail that loops past frozen caves, tunnels and canyons and avoids hidden crevasses, water-filled pits or holes that can descend hundreds of feet into the ice. But that month, Matanuska Glacier Park began requiring any first-time winter visitor without glacier travel experience to pay for a tour — like it or not.”
Downward Trend of Organic Pollutants in Antarctica
From Chemosphere: “Passive air samplers were used to evaluate long-term trends and spatial distribution of trace organic compounds in Antarctica. Duplicate PUF disk samplers were deployed at six automatic weather stations in the coastal area of the Ross sea (East Antarctica), between December 2010 and January 2011, during the XXVI Italian Scientific Research Expedition… In general, the very low concentrations reflected the pristine state of the East Antarctica air. Backward trajectories indicated the prevalence of air masses coming from the Antarctic continent. Local contamination and volatilization from ice were suggested as potential sources for the presence of persistent organic pollutants in the atmosphere.”
From the Journal of Glaciology: “An anomalously slight glacier mass gain during 2000 to the 2010s has recently been reported in the Karakoram region. We calculated elevation and mass change using Digital Elevation Models (DEMs) generated from KH-9 (a series of satellites) images acquired during 1973–1980… Within the Karakoram, the glacier change patterns are spatially and temporally heterogeneous. In particular, a nearly stable state in the central Karakoram (−0.04 ± 0.05 m w.e. a−1 during the period 1974–2000) implies that the Karakoram anomaly dates back to the 1970s. Combined with the previous studies, we conclude that the Karakoram glaciers as a whole were in a nearly balanced state during the 1970s to the 2010s.”
From Quaternary Science Reviews: “The chemical and physical characterization of the dust record preserved in ice cores is useful for identifying of dust source regions, dust transport, dominant wind direction and storm trajectories. Here, we present a 50,000-year geochemical characterization of mineral dust entrapped in a horizontal ice core from the Taylor Glacier in East Antarctica. Strontium (Sr) and neodymium (Nd) isotopes, grain size distribution, trace and rare earth element (REE) concentrations, and inorganic ion (Cl− and Na+) concentrations were measured in 38 samples, corresponding to a time interval from 46 kyr before present (BP) to present… This study provides the first high time resolution data showing variations in dust provenance to East Antarctic ice during a major climate regime shift, and we provide evidence of changes in the atmospheric transport pathways of dust following the last deglaciation.”
From Current Microbiology: “The prokaryotic (microscopic single-celled organisms without a distinct nucleus with a membrane or other specialized organelles) abundance and diversity in three cold, oligotrophic Patagonian lakes (Témpanos, Las Torres and Mercedes) in the northern region Aysén (Chile) were compared in winter and summer…Prokaryotic abundances, numerically dominated by Bacteria, were quite similar in the three lakes, but higher in sediments than in waters, and they were also higher in summer than in winter… The prokaryotic community composition at Témpanos lake, located most northerly and closer to a glacier, greatly differed in respect to the other two lakes. In this lake was detected the highest bacterial diversity… Our results indicate that the proximity to the glacier and the seasonality shape the composition of the prokaryotic communities in these remote lakes. These results may be used as baseline information to follow the microbial community responses to potential global changes and to anthropogenic impacts.”
“Scientists had long assumed that India and China—two of the world’s leading sources of black carbon pollution—were responsible for what fell on the glaciers in Tibet and the Himalayas[….] Instead, he found that a lot of the black carbon is local. While power plants in China and fires in India do contribute black carbon, in the remote interior of the Tibetan Plateau it appears to come mostly from burning yak dung and other immediate sources.”
Click here to read more about the small but mighty power of yak dung.
Pakistan expands glacier monitoring in effort to cut disaster risk
“Pakistan will invest $8.5 million to expand a network of glacier monitoring stations tracking the pace of glacial melt in the Hindu Kush, Karakoram and Himalayan mountain ranges, in an effort to strengthen early warning systems and reduce the impact of flooding in the South Asian country.”
Click here to learn more about Pakistan’s new glacial monitoring research program.