Latest news with #AustralianAntarcticProgramPartnership
Perth Now
5 days ago
- Science
- Perth Now
Sea ice loss risks more icebergs, threatens wildlife
The oceans around Antarctica have been trending warmer leading to more ice loss. (HANDOUT/AUSTRALIAN ANTARCTIC DIVISION) The oceans around Antarctica have been trending warmer leading to more ice loss. (HANDOUT/AUSTRALIAN ANTARCTIC DIVISION) Credit: AAP Extreme sea ice loss in Antarctica over the past few years is leading to higher ocean temperatures, more icebergs and habitat dangers for penguins. The oceans surrounding the southern continent have already been trending warmer than average and researchers say the ongoing loss of sea ice is contributing as dark water absorbs more sunlight without a reflective frozen barrier. Species like the Crabeater seal and Adelie penguin rely on sea ice for habitat, with the latter reliant on large chunks during their "catastrophic moult" period when they need to stay dry for weeks at a time. Less sea ice will make it harder for the penguins to find a suitable spot to shed their feathers, leaving them more exposed to predators. Tougher conditions for ships supplying Antarctic missions are also a problem with low ice coverage, the international study led by Australian Antarctic Program Partnership researchers has found. Really low summer sea ice is also associated with more icebergs breaking away from the coastline. Years with the least summer sea ice have produced more than twice as many icebergs as the years with the most summer sea ice. Lead author of the study, the AAPP's Edward Doddridge, said up until about 2015, sea ice was around average or even a bit above. "But since 2016 it has been consistently low, and the last few years have been extraordinarily low," he said during a media briefing. The wide-ranging study into the consequences of sea ice loss lands as uncertainty clouds the future of global climate science under the Trump administration. Dr Doddridge said the US Department of Defense planned to stop sharing its global sea ice coverage satellite data with the international community. The uncertainty was "deeply concerning", the sea ice scientist said, but other country's satellites would continue to supply some information. Other Australian-based climate researchers have been alert to risks hanging over earth observation data and climate modelling, given the US has traditionally played a major role. Christian Jakob, director of the Australian Research Council Centre of Excellence for 21st Century Weather, was worried about the growing possibility of losing access to the satellite data that was key to global cloud coverage research. Cloud cover shrinkage is thought to be contributing to unexpectedly fast warming. "If those satellites were not renewed, if there were no successors to these satellite missions, then some of the information we have will disappear," Professor Jakob told AAP. Research into the impacts of sea ice loss highlights a number of knowledge gaps but report co-author Will Hobbs, also from the University of Tasmania's AAPP, said the findings supported a rapid transition to net zero. "Climate projections indicate that continued greenhouse gas emissions will accelerate the changes in Antarctica and the Southern Ocean that we're already seeing, and exacerbate the far-reaching negative impacts of sea-ice loss," Dr Hobbs said.
The Age
5 days ago
- Science
- The Age
How sea ice affects the global ocean climate
This map is a Spilhaus projection, showing the world's seas and oceans as a single body of water, centred on Antarctica and bordered by continents. Source: Australian Antarctic Program Partnership.
Sydney Morning Herald
5 days ago
- Science
- Sydney Morning Herald
How sea ice affects the global ocean climate
This map is a Spilhaus projection, showing the world's seas and oceans as a single body of water, centred on Antarctica and bordered by continents. Source: Australian Antarctic Program Partnership.
Miami Herald
04-05-2025
- Science
- Miami Herald
Antarctic voyage reveals creatures of the deep while exploring glacier. See them
Armed with lab equipment and two months of food and clothes, around 60 researchers boarded the RSV Nuyina icebreaker ship for its first scientific voyage in March. They are taking part in the Denman Marine Voyage, a trip from Australia to Antarctica to study the Denman Glacier and its ecosystem. Now, nearing the end of the journey, the research team is reporting some of its results and the interesting creatures it is finding along the way. The voyage launched from Hobart, Tasmania, with 45 crew members, 25 support staff and 60 scientists from four organizations — the Australian Antarctic Division, the Australian Centre for Excellence in Antarctic Science, the Australian Antarctic Program Partnership and Securing Antarctica's Environmental Future, according to an April 2 news release shared by the Australian Antarctic Division to McClatchy News. 'The main aim of the voyage is to better understand how factors such as warmer ocean waters are influencing changes in the (62-mile-long) Denman Glacier — which has retreated (3 miles) in the past two decades,' according to the organization. 'If the Denman were to melt entirely, it could contribute about (5 feet) to global sea level rise.' Researchers have collected data on conductivity, temperature and depth of the seawater, as well as 'ancient organic material' and debris from the ice sheet collected in sediment cores from the seafloor, the Australian Antarctic Division said. Some teams are also studying how clouds form in the Southern Ocean, hoping to improve climate modeling. But another part of the voyage is understanding the region's biodiversity, and some creatures seemed to volunteer for science. In the first five weeks of the trip, a 'sea butterfly' or 'delicate pteropod,' was pulled into the icebreaker's wet well, according to the Australian Antarctic Division. 'It has started producing eggs in the aquarium, allowing researchers to document pteropod egg development for the first time,' according to the release. It's a species called Clio pyramidata, and was nicknamed 'Clio' by the team, the organization said. 'The team is super excited about having the little creature and observing it and looking after it, so that it tells all the secrets that have been hidden until now,' researcher Laura Herraiz Borreguero told ABC News, the Australian Broadcasting Corp. Aside from the 'sea butterfly,' researchers also collected sea spiders, sea stars, octopus and 'sea pigs,' according to the release. Sea pigs, or scotoplanes, are species of sea cucumbers with appendages that make them appear like small pigs, and they are often pink in color, according to the Monterey Bay Aquarium. 'The sea pig spends its days snuffling though the muddy sediments on the seafloor, eating bits of dead algae and animals that have fallen from the surface,' the aquarium said. 'When something big, like a whale fall, sinks to the seafloor, huge herds of sea pigs gather nearby to feast on the rich organic sediments from the decaying carcass.' The RSV Nuyina and its passengers will return to Tasmania in early May, about a 3,100-mile journey, where the data collected from the research voyage can be studied and logged, according to the release. Tasmania is an island territory off the southeastern coast of Australia.
Washington Post
06-02-2025
- Science
- Washington Post
The world's largest iceberg is on the move again
After eight months trapped in a whirlpool in the Southern Ocean, the world's largest iceberg is on the move again — and potentially on a path to hit the island of South Georgia. The island, located between Antarctica and Argentina, is a haven for vulnerable populations of penguins, seals and seabirds. The iceberg in question is A-23A, sometimes called A23a. It is the world's oldest and largest — about the size of Rhode Island — and weighs nearly 1 trillion tonnes. As it moves along, the biggest concern, scientists say, is whether the iceberg or its bits could block access to parts of the island for wildlife or ships. Previous iceberg collisions have affected food foraging on the island. The ice slab is meandering and moving parallel to South Georgia Island, oceanographer Andrew Meijers said. Currents are expected to loop A-23A back to South Georgia's continental shelf in about two weeks. 'If it does ground on the continental shelf ... this could pose a significant problem for seals and [penguins] presently feeding their chicks and pups,' said Meijers, a researcher at the British Antarctic Survey. The iceberg is drifting in a current at about 1 kilometer per hour (about 0.62 miles per hour) toward South Georgia. Although its arrival could occur in weeks, Meijers said, 'it is hard to be precise as wind and wave action can also be important and eddies in the current are very hard to predict.' 'The iceberg might take a turn around South Georgia like many before it' or smaller pieces broken off from the iceberg could run aground, said Jan Lieser, marine glaciologist at the Australian Antarctic Program Partnership. South Georgia Island is a difficult place for humans to live, but it is a haven for wildlife. Its productive waters support abundant populations of krill, which serve as food for many marine predators like fur seals. In fact, more than 3.5 million fur seals live on the island, which is about 95 to 98 percent of the world's population of the animal. Deep bays also provide homes for millions of penguins and seabirds — including the wandering albatross, which is threatened. In 2004, an iceberg grounded on the north side of South Georgia and was associated with more seal pup and penguin chick mortalities, Meijers said. When the iceberg grounded, it likely made foraging more difficult. 'The adults must swim further to go around the berg and thus expend more energy and bring back less,' Meijers said. In 2021, another iceberg about the size of Delaware appeared on a collision course with South Georgia but then fractured into smaller pieces around the island. The British Antarctic Survey expects A-23A to encounter warmer water and break up into smaller icebergs and, eventually, melt. If iceberg A-23A breaks up before hitting the island, the impact will be lessened because smaller chunks are easier for wildlife to go around. Fishing vessels, though, might have a harder time navigating around thousands of smaller chunks, Meijers said. One chunk — measuring 80 square kilometers — broke off A-23A in late January. Leiser said the piece is large enough to be given identifying numbers and letters by the U.S. National Ice Center. Now, A-23A is sitting in 'a bit of storm' with sustained winds around 70 kilometers per hour (about 44 miles per hour) and waves as high as 6 meters (about 6½ feet), Meijers said. This storm may speed up the break up of the iceberg. The iceberg's path isn't unusual, nor is it the first to venture to South Georgia Island. Iceberg A-23A broke off the Filchner-Ronne Ice Shelf to the northeast of the West Antarctic Ice Sheet in 1986. It then spent decades stuck to the seafloor. In the early 2020s, the iceberg began to loosen and by March 2023, it floated freely. One year later, as it drifted north, it became trapped in a gyre — and it would remain in the rotating system of ocean currents until it escaped several months later. The mass mostly took the same path as other large icebergs exiting the Weddell Sea, heading down 'iceberg alley,' Lieser said. Iceberg alley starts on the northeastern side of the Antarctic Peninsula and generally heads northeast past the South Orkney Island and South Georgia Island into the South Atlantic Ocean. 'The unusual part of the iceberg's journey was the long time it was trapped in this oceanic gyre,' said Lieser, who is also a research associate at the Institute for Marine and Antarctic Studies at the University of Tasmania. This ocean gyre is known as a Taylor column, where rotating water above a seamount trapped the iceberg from drifting north. Imagine placing a stick in a swirling bucket of water; the water flowing around the stick forms a Taylor column. Lieser doesn't know why the iceberg escaped the vortex, but hypothesizes that a 'random perturbation in the system' might have affected its 'usual spin,' allowing the iceberg to find an exit path. Only time will tell if iceberg A-23A will make another rare maneuver onto South Georgia and disrupt the animals. 'The exact degree of impact will depend on how closely the berg grounds, and whether or not this sits on the optimal path to [or] from the breeding beaches and feeding ground,' Meijers said. 'This is pretty much impossible to predict.'
