Latest news with #PeterFretwell
Yahoo
24-03-2025
- Science
- Yahoo
What's Beneath All That Ice In Antarctica? New Map Reveals The Hidden World And Possibly The Future
What comes to mind when you think of Antarctica? Probably snow and ice. But a group of international scientists are shaking up what we think we know about the continent after unveiling a new, very detailed map of everything beneath the millions of miles of ice. The map, called Bedmap3, gives a clear view of the towering mountains and deep canyons hidden by the ice sheets. It was compiled using more than 60 years of data from planes, satellites, ships and even sleds pulled by dogs. The British Antarctic Survey led the study and the results were published in the journal Scientific Data. As the name of the map implies, this is the third effort to illustrate Antarctica's rock bed. The project began in 2001, but the researchers involved say the new map represents a dramatic refinement using 82 million data points. That data includes recent surveys in East Antarctica, which helped fill big gaps in our collective knowledge of the region, including around the South Pole. One notable discovery is that Antarctica's thickest ice was found in an unnamed canyon in Wilkes Land. The ice there is more than 15,000 feet thick. Earlier maps placed the thickest ice in the Astrolabe Basin In Adelie Land. Here's why this new map is critical: It will help researchers figure out how Antarctica might respond to warming temperatures. "This is the fundamental information that underpins the computer models we use to investigate how the ice will flow across the continent as temperatures rise," said Dr. Hamish Pritchard, a glaciologist at BAS and the study's lead author. "Imagine pouring syrup over a rock cake – all the lumps, all the bumps, will determine where the syrup goes and how fast. And so it is with Antarctica: some ridges will hold up the flowing ice; the hollows and smooth bits are where that ice could accelerate." So could this map also be a chilling look at Antarctica's future under a worst-case scenario? This group of scientists did not go that far, but they did discover that those ice sheets are thicker than once thought. Here's what Peter Fretwell, mapping specialist and co-author at BAS, says: "In general, it's become clear the Antarctic Ice Sheet is thicker than we originally realized and has a larger volume of ice that is grounded on a rock bed sitting below sea level. This puts the ice at greater risk of melting due to the incursion of warm ocean water that's occurring at the fringes of the continent. What Bedmap3 is showing us is that we have got a slightly more vulnerable Antarctica than we previously thought." MORE ON - Surprising Discovery Under Antarctic Ice Shelf - Your Area Could Be Next: Tornado Risk Is All Year - Top 10 Worst Cities For Allergy Sufferers
USA Today
19-03-2025
- Science
- USA Today
What's under all that ice in Antarctica? New map has answers.
What's under all that ice in Antarctica? New map has answers. Show Caption Hide Caption Do people live in Antarctica? What to know about the icy continent. Do people live in Antarctica? What to know about the continent's residents and visitors. Have you ever wondered what Antarctica might look like without ice? Now, a new map released this week gives us a clear view of the continent as if its massive sheet of ice has been removed, revealing the hidden locations of its tallest mountains and the deepest canyons. The mapping effort, called Bedmap3, includes far more detail than previous maps and includes millions more data points. "In general, it's become clear the Antarctic ice sheet is thicker than we originally realized," said Peter Fretwell of the British Antarctic Survey, which produced the map. A mix of good news and bad news about butterflies: They in trouble, but it doesn't take much to help. The findings were published this week in the journal Scientific Data. What is an ice sheet? Ice sheets are masses of glacial land ice extending more than 20,000 square miles, the National Snow and Ice Data Center said. There are only two ice sheets worldwide today, the Antarctic and Greenland ice sheets. They contain more than 99% of the land ice on Earth. The huge size of the ice sheets means that the loss of even a small fraction of their total ice can significantly raise sea levels. From 2002 to 2017, for example, due to global warming, ice sheet losses accounted for roughly a third of mean sea level rise. The Antarctic ice sheet, which covers 98% of the continent, averages around 1.2 miles in thickness, with its thickest point reaching nearly 3 miles, the Australian Antarctic Program reports. Read more news about our planet: Sign up for USA TODAY's Climate Point newsletter. Why is the map important? 'This is the fundamental information that underpins the computer models we use to investigate how the ice will flow across the continent as temperatures rise," said Hamish Pritchard, a glaciologist at BAS and lead author of the study. A mix of good news and bad news about butterflies: They in trouble, but it doesn't take much to help. Known as Bedmap3, the map incorporates more than six decades of survey data acquired by planes, satellites, ships and even dog-drawn sleds. The outline of deep valleys is better represented in the new map, the BAS said. So too are those places where rocky mountains stick up through the ice. "The latest satellite data have also more accurately recorded the height and shape of the ice sheet and the thickness of the floating ice shelves that push out over the ocean at the continent's margin," the BAS said in a statement. A 'vulnerable Antarctica' Scientists said the map revealed that the ice sheet is at greater risk of melting due to the incursion of warm ocean water that's occurring at the fringes of the continent. "What Bedmap3 is showing us is that we have got a slightly more vulnerable Antarctica than we previously thought," Fretwell said.
Yahoo
13-03-2025
- Science
- Yahoo
World hidden beneath Antarctic ice reveals staggering reality: 'Greater risk'
If you've ever wondered what lies beneath Antarctica's icy surface, then this map will blow your mind. Scientists documenting a hidden rocky world have revealed its terrain includes tall mountains and the deep canyons that no human has ever seen. The map was created by a team of international scientists led by the British Antarctic Survey (BAS). Named Bedmap3, it was published in the journal Scientific Data today, and as its name suggests, it's the third attempt to map the continent's rock bed since 2001. The map includes important revisions, including that Antarctica's thickest overlying ice is at a different part of Australia's Antarctic Territory than previously thought. New data suggests it's at Wilkes Land, not at the Astrolabe Basin. At 4,757 metres, its depth is more than four times the length of the Sydney Harbour Bridge. Related: 🦟 'Unimaginable' theory emerges about desolate continent As well as being fascinating to see, the map is expected to play an important role in determining how the continent will be modified as climate change warms the planet. BAS Dr glaciologist Hamish Pritchard explained the ground that lies beneath the ice will direct the flow of the melt. 'Imagine pouring syrup over a rock cake – all the lumps, all the bumps, will determine where the syrup goes and how fast. And so it is with Antarctica: some ridges will hold up the flowing ice; the hollows and smooth bits are where that ice could accelerate,' he said. The cartographers were informed by 60 years of data collected by adventurers on dog sleds, modern satellites, and passengers on ships and planes. They also used radar, sound waves and gravity measurements to build a picture of what the continent would look like without 27 million cubic kilometres of ice. 🏡 Aussies urged to fit $7 'lifesaving' Bunnings device to homes 🐣 Once common Aussie bird among 21 new species facing extinction 😳 Weed sparks major concern after scary discovery Alarmingly, BAS mapping specialist Peter Fretwell believes the revisions show Antarctica could be more 'slightly more' vulnerable to climate change than first thought. If all the ice on the continent was to melt, global seas could rise by more than 58 metres. "In general, it's become clear the Antarctic Ice Sheet is thicker than we originally realised and has a larger volume of ice that is grounded on a rock bed sitting below sea-level. This puts the ice at greater risk of melting due to the incursion of warm ocean water that's occurring at the fringes of the continent,' he said. Love Australia's weird and wonderful environment? 🐊🦘😳 Get our new newsletter showcasing the week's best stories.
Sky News
04-03-2025
- Science
- Sky News
World's largest iceberg runs aground in South Georgia and blocks off key penguin feeding ground
After nearly 40 years at sea, the world's largest iceberg has run aground on the remote British overseas territory of South Georgia, one of the biologically rich habitats on Earth home to millions of penguins, seals and endangered albatross. The vast "megaberg" named A23a covers 1,200 square miles - roughly the size of Gloucestershire. Now it has grounded it is expected to break up, threatening to prevent penguins and other sea-life from accessing crucial feeding grounds and the fishing vessels operating in the area. Last week as it approached South Georgia it was moving "very fast," according to Dr Andrew Meijers, an oceanographer at the British Antarctic Survey in Cambridge. "It was covering 30km a day, fairly ripping along for an iceberg," he said. Then on Friday it suddenly stopped, its corner snagging the seafloor about 40 miles off the southwest coast of South Georgia. 0:22 The stress of the collision, tides and currents are likely to speed the breakup of the 'berg in the warmer waters - 1,200 miles from Antarctica where it began its long, slow journey. A23a broke off from Antarctica's Filchner-Ronne ice shelf in 1986, carrying a Soviet research station Druzhnaya built on it into the Wedell Sea. The 'berg barely moved for 20 years, then in 2020 began drifting slowly north. It spent six months last year spinning in a revolving ocean current in the Southern Ocean before finally breaking free in the New Year on a collision course with South Georgia. Apart from a handful of visiting scientists and officials representing the Falkland Islands -based government of South Georgia, the island is uninhabited - by people at least. "This area is extremely important for penguins," said Peter Fretwell, a geospatial information scientist also at the British Antarctic Survey. Several million penguins including macaroni, chinstrap, gentou and king penguins call South Georgia home. As do several species of albatross, elephant seals and fur seals. The ocean around the islands is also increasingly important for whales, now returning after hunting them was banned. The iceberg is blocking a vast area of ocean that is an important feeding ground for macaroni penguins - South Georgia is home to one of the world's largest colonies. As it melts, A23a will be releasing millions of gallons of fresh water into the ocean each day. Because fresh water floats on top of heavier seawater, it has the potential to force nutrients - and therefore the shrimp-like krill penguins feed on - deeper into the water column. "If it's very clean water, it will introduce a halo of low-productivity around the iceberg," said Mr Fretwell. However, the opposite could also happen. Some icebergs carry a lot of sediment with them, scraped from the rocks of Antarctica. Once released into the ocean this sediment can add nutrients to the water - potentially boosting the amount of food available for penguins. Megabergs of this size are rare, too few for scientists to know if they're becoming more common or not. However, they're emblematic of a clear warming trend in the Antarctic that is causing the increasingly rapid melting of its ice sheets, which are the world's largest. The continent is losing around 150 billion tonnes of water in the form of ice a year, half carried away as icebergs, the rest due to ice melting directly off the continent itself. A key concern is whether all that fresh water will disrupt what is effectively our planet's cooling system. The Antarctic Circumpolar Current - a conveyor belt of cold water running around Antarctica - is the single most important system that removes rising levels of heat from our atmosphere. Warm air from the rest of the planet heats the surface waters, and currents then draw this warmer water down, replacing it with cooler water from the depths of the ocean. "It does all of the heavy lifting in terms of trapping heat from global warming," said Dr Meijers. Microscopic plants - phytoplankton - in the region also absorb the most planet-warming carbon dioxide, which is, like the warmer water, carried deep into the oceans and stored there. A recent study suggests fresh water from melting icebergs and the Antarctic continent is already slowing this circumpolar current and may reduce its speed by 20% by 2050.
