Latest news with #iceberg
Gizmodo
2 days ago
- Science
- Gizmodo
Scientists Uncover Surprising Link Between Tides and Earth's Biggest Icebergs
In 2021, researchers in Antarctica noticed giant cracks developing on the Brunt Ice Shelf, an enormous stretch of ice on the continent's northwestern corner. Two years later, the fracture grew so large that a gigantic iceberg almost twice the size of New York City broke free in a process called calving, sending scientists scrambling to investigate the icy chunk, which they named iceberg A-81. A team of researchers affiliated with the British Antarctic Survey sought to understand the forces driving this 'crack behavior' in the huge ice shelf. By devising a mathematical model to account for natural forces affecting ice shelves, the researchers found that iceberg A-81—and most other icebergs, for that matter—likely snapped off from tidal forces buffeting the ice shelves in spring, when the currents are strongest. The paper, published in Nature Communications on July 24, supports common-sense assumptions about environmental forces playing a major role in driving calving events, but the proposed model could also improve prediction models for calving events, a historically challenging task. 'Understanding what controls the timing of these events is crucial, because calving not only affects the shape and melt rate of ice shelves but also their long-term stability,' said study lead author Oliver Marsh, in a statement. 'It's incredibly exciting to uncover a link between something as predictable as the tides and the dramatic, sudden process of iceberg calving.' For the paper, Marsh and his colleagues first devised a mathematical model to calculate the threshold for crack behavior in the ice shelves using ocean tides or wind patterns as potential stressors. Next, they tested their predictions against GPS and radar data, paying close attention to the subtle movements and stresses that appeared within the ice shelf over time. They noticed that the fractures tended to grow most in spring, which happens to be when tides are strongest. The model, however, is a simplified interpretation of real-life dynamics in Antarctica, the study authors admitted, and it better explains smaller, gradual changes in crack behavior. This means that more dramatic events—like extreme temperatures from climate change—will cause even bigger rifts in the ice. 'Tides and wind are key to the timing of small individual rift growth events here,' the authors wrote in the paper, 'but it is notable that an iceberg collision in 2021 caused more substantial rift growth in a single event than throughout 2020.' Nevertheless, the study marks a crucial step in modeling the role of environmental drivers in calving events, which the authors argue will subsequently inform our models of iceberg calving under such extreme atmospheric or ocean conditions. Large icebergs also influence ocean circulation and local ecosystems, so the new model could serve as a useful tool for structuring research projects in Antarctica, Marsh explained. 'Icebergs like A-81 can be thousands of square kilometers in size and account for roughly half of all ice lost from Antarctica each year,' Marsh said. 'This kind of insight brings us closer to forecasting major ice loss events and their impact on sea level with far greater precision.'
France 24
5 days ago
- Science
- France 24
Tides could help predict when huge icebergs break loose: study
It is not normally possible to forecast when icebergs break free, or calve, although the timing is important because these behemoths change the shape of ice sheets and affect global sea levels. Yet when a chunk of ice the size of Greater London suddenly broke off the Brunt Ice Shelf in 2023 and started drifting away, glaciologist Oliver Marsh was not surprised. Marsh told AFP he had predicted that a huge iceberg breaking off was "imminent within the next weeks to months". The British Antarctic Survey researcher had spent years studying the huge crack that would create the 550-square-kilometre (210-square-mile) iceberg named A81. As Marsh had anticipated, the calving occurred at the peak of spring tide, when there is the biggest difference between the ocean's high and low tide. New research led by Marsh, published in the journal Nature Communications on Thursday, used modelling to show that the calving was triggered by the tide, along with high winds and stress on the ice. After A81 broke off, Marsh visited the ice shelf to see how open water had replaced what had previously been "ice as far as you could see". "It was sad to see it go, in a way," he said. A81 is currently drifting up the eastern side of the Antarctica Peninsula towards the Weddell Sea. It remains to be seen whether it will come close to South Georgia island, which is an important breeding ground for penguins, seals and other animals. 'Out of balance' The world's biggest iceberg, A23a, ran aground not too far from South Georgia earlier this year but is not thought to pose a threat to wildlife. Now that A23a is exposed to the waves of the Southern Ocean, its "days are numbered", Marsh said. He emphasised that iceberg calving is a natural process which balances out the massive amount of snow that falls on Antarctica every year. However, "now we're out of balance", Marsh added. Antarctica loses ice in two ways -- icebergs calving and ice sheets melting. And ice sheets are melting at a rapidly increasing rate as oceans warm due to human-driven climate change, scientists have warned. "We don't know whether calving rates have gone up" because they happen relatively infrequently, Marsh said. A81 was the second of three mammoth icebergs that have broken free of the Brunt Ice Shelf since 2021. "We are expecting a very large calving event at some point from this area" in the future, Marsh said. But he could not give a timeframe. © 2025 AFP
News.com.au
12-07-2025
- Climate
- News.com.au
Greenland village wakes up to titanic iceberg dangerously close to homes
A small settlement in Greenland is holding its collective breath as an iceberg of titanic proportions drifts dangerously close to shore — and residents' homes. For days now, the freakishly large frozen mass has been on a collision course with tiny Innaarsuit — leading local authorities to issue a warning to residents. If the fearsome frosty float were to make contact with the shore or break apart, potential damage and injuries could follow, officials said. Though it's unlikely any broken ice chunks would fall directly on land, the impact of pieces of plummeting permafrost would create massive waves, which could sweep ashore. These swells could cause immediate structural harm, or at their worst, wash away low-lying or already compromised structures entirely. Innaarsuit is located on a small island in western Greenland, and the local economy revolves primarily around fishing. Government representatives cautioned against getting too close to the iceberg when sailing to and from the island, or even while going about daily activities on dry land. 'Emergency services encourage families not to go in a group towards the store, while at the same time asking people with walking difficulties to be extra careful when walking towards the store,' they said. Typically, large icebergs move within a few days, but according to local worker Dennis Lehtonen, it's been stationary for around a week, which is the main source of worry. 'Because of this, the [local municipality] issued the official warning for the iceberg and we are temporarily closing the local fish factory where I work as well as the small shop,' Lehtonen said. Despite the towering magnitude of the frosty float, not all of the town's residents are bothered by its presence. 'I have asked the locals about their feelings for the iceberg. Some say they're worried, but there are plenty of people who are sort of excited (like me),' he added. This isn't the first time a hulking iceberg has sailed on into the Innaarsuit harbour. Back in 2018, a similarly sized mass floated into the same harbour, and at 11 tons, it was so large it could be seen from space. At the time, residents near areas that could be impacted were evacuated to higher ground. The 2018 iceberg eventually floated away — after being assailed by days of consistently strong winds.
Yahoo
12-07-2025
- Science
- Yahoo
Greenland coastal village bracing for potential collision with giant iceberg
An enormous iceberg is drifting dangerously close to the shore in northwestern Greenland The skyscraper-sized piece of ice is on a potential collision course with the harbour of Innaarsuit, a village in Greenland's Avannaata Municipality. It originally sidled up to the village last week, but seemed to have drifted away before reappearing on Monday and remaining precariously close. Local authorities have issued warnings to residents as the iceberg sits near the Royal Greenland fish factory and the local grocery store. People have been advised to take care when in that part of the community. Emergency services are encouraging families not to go in a group towards the store. They are also asking people who have difficulty walking to be extra careful. The fish-processing factory has been temporarily closed. Meanwhile, locals have been advised to be careful when sailing to or from the settlement. While some residents are concerned, others are reportedly excited by the rare and dramatic sight. There are few options for dealing with threatening icebergs. One of the main concerns with a large iceberg is that it will 'calve' (split), with pieces falling into the ocean, resulting in large waves that will swamp nearby coastal communities. As a result, authorities monitor icebergs for cracks and holes that may result in calving. The first line of defence is for nearby residents to evacuate. That occurred in 2018, when this same Greenlandic community was similarly threatened. Other options have been considered but remain experimental. They involve explosives to break up the iceberg and towing. These tactics present monumental challenges. The U.S. Coast Guard says aside from difficulty involved in successfully getting onto an iceberg, demolition would require 'a 1,000 lb. charge of conventional explosives…to break up approximately 70,000 cubic ft of ice (an iceberg weighing 1,960 tons).' Further, a hundred of these charges would be needed to destroy an average iceberg, (presumably more for the mammoth berg threatening Innaarsuit at this time). Melting a medium-sized iceberg of 100,000 tons would theoretically require heat from the 'combustion of over a quarter of a million gallons of gasoline' says the Coast Guard. 'Such methods are, of course, economically, as well as practically unsound.' Icebergs drift south after calving from Arctic and western Greenland glaciers. They are regular sights in spring-early summer. Transported by Atlantic Ocean currents to waters off Greenland, Newfoundland and Labrador, as well as Cape Breton Island, they eventually melt in somewhat warmer southern climes. An iceberg that drifts south rarely lasts more than a year. Icebergs flow at speeds of up to seven kilometres a year, first floating in Arctic bays before passing into the Labrador Current and south into what is known as 'Iceberg Alley.' Every year about 40,000 medium to large icebergs calve from glaciers but only 400-800 make it as far south as St. John's. However, those numbers can vary greatly from year to year based on temperature, ocean current, wind direction and sea/pack ice. Often huge, ninety per cent of an iceberg sits below the ocean surface. Black iceberg spotted off Labrador could be result of an asteroid strike Unusual iceberg with giant hole attracts onlookers to Eastern Newfoundland cove Our website is the place for the latest breaking news, exclusive scoops, longreads and provocative commentary. Please bookmark and sign up for our daily newsletter, Posted, here.
Yahoo
12-07-2025
- Science
- Yahoo
Greenland coastal village bracing for potential collision with giant iceberg
An enormous iceberg is drifting dangerously close to the shore in northwestern Greenland The skyscraper-sized piece of ice is on a potential collision course with the harbour of Innaarsuit, a village in Greenland's Avannaata Municipality. It originally sidled up to the village last week, but seemed to have drifted away before reappearing on Monday and remaining precariously close. Local authorities have issued warnings to residents as the iceberg sits near the Royal Greenland fish factory and the local grocery store. People have been advised to take care when in that part of the community. Emergency services are encouraging families not to go in a group towards the store. They are also asking people who have difficulty walking to be extra careful. The fish-processing factory has been temporarily closed. Meanwhile, locals have been advised to be careful when sailing to or from the settlement. While some residents are concerned, others are reportedly excited by the rare and dramatic sight. There are few options for dealing with threatening icebergs. One of the main concerns with a large iceberg is that it will 'calve' (split), with pieces falling into the ocean, resulting in large waves that will swamp nearby coastal communities. As a result, authorities monitor icebergs for cracks and holes that may result in calving. The first line of defence is for nearby residents to evacuate. That occurred in 2018, when this same Greenlandic community was similarly threatened. Other options have been considered but remain experimental. They involve explosives to break up the iceberg and towing. These tactics present monumental challenges. The U.S. Coast Guard says aside from difficulty involved in successfully getting onto an iceberg, demolition would require 'a 1,000 lb. charge of conventional explosives…to break up approximately 70,000 cubic ft of ice (an iceberg weighing 1,960 tons).' Further, a hundred of these charges would be needed to destroy an average iceberg, (presumably more for the mammoth berg threatening Innaarsuit at this time). Melting a medium-sized iceberg of 100,000 tons would theoretically require heat from the 'combustion of over a quarter of a million gallons of gasoline' says the Coast Guard. 'Such methods are, of course, economically, as well as practically unsound.' Icebergs drift south after calving from Arctic and western Greenland glaciers. They are regular sights in spring-early summer. Transported by Atlantic Ocean currents to waters off Greenland, Newfoundland and Labrador, as well as Cape Breton Island, they eventually melt in somewhat warmer southern climes. An iceberg that drifts south rarely lasts more than a year. Icebergs flow at speeds of up to seven kilometres a year, first floating in Arctic bays before passing into the Labrador Current and south into what is known as 'Iceberg Alley.' Every year about 40,000 medium to large icebergs calve from glaciers but only 400-800 make it as far south as St. John's. However, those numbers can vary greatly from year to year based on temperature, ocean current, wind direction and sea/pack ice. Often huge, ninety per cent of an iceberg sits below the ocean surface. Black iceberg spotted off Labrador could be result of an asteroid strike Unusual iceberg with giant hole attracts onlookers to Eastern Newfoundland cove Our website is the place for the latest breaking news, exclusive scoops, longreads and provocative commentary. Please bookmark and sign up for our daily newsletter, Posted, here.
