Icebergs as large as cities, potentially tens of kilometres wide, once roved the coasts of the UK, according to scientists. Researchers found distinctive scratch marks left by the drifting icebergs as they gouged deep tracks into the North Sea floor more than 18,000 years ago. It's the first hard evidence that the ice sheet formerly covering Britain and Ireland produced such large bergs. The findings could provide vital clues in understanding how climate change is affecting Antarctica today. The scientists searched for fingerprints of giant icebergs using very detailed 3D seismic data, collected by oil and gas companies or wind turbine projects doing ocean surveys. This is a bit like doing an MRI scan of the sediment layers beneath the present-day seafloor, going back millions of years. The researchers found deep, comb-like grooves, interpreted to have been created by the keels of large icebergs that broke off the British-Irish ice sheet more than 18,000 years ago. Some of these scratch marks are as close as 90 miles (145km) to Scotland's present-day east coast. "We found [evidence of] these gigantic tabular icebergs, which basically means the shape of a table, with incredibly wide and flat tops," said James Kirkham, marine geophysicist at the British Antarctic Survey and lead author of the new study, published in the journalNature Communications. "These have not been seen before and it shows definitively that the UK had ice shelves, because that's the only way to produce these gigantic tabular icebergs." Ice shelves are floating platforms of ice where glaciers extend out into the ocean. By analysing the size of the grooves, the scientists estimate that these icebergs could be five to tens of kilometres wide and 50-180m thick, although it's difficult to be exact. That means they would have covered an area roughly as big as medium-sized UK cities like Norwich or Cambridge. The icebergs are comparable in size to some of the smaller icebergs found off present-day Antarctica, such as blocks that calved fromthe Larsen B ice shelf in 2002. Dr Kirkham described seeing such an iceberg when working in Antarctica two years ago. "Those of us working on this paper were standing together, gazing out onto this iceberg and thinking, 'Wow, that's probably a similar size iceberg to what was found off the shore of Scotland 18,000 years ago, right in front of us in Antarctica today.'" Hundreds of ice shelves surround about three-quarters of today's Antarctic ice sheet, helping to hold back its vast glaciers. But if ice shelves are lost, the glaciers behind can speed up, depositing more and more ice into the ocean and raising sea levels worldwide. Exactly how this plays out, though, is "one of the largest sources of uncertainty in our models of sea level rise", Dr Kirkham told BBC News. That's partly because scientists have only been able to use satellites for a few decades to observe about 10 cases of ice shelves collapsing - hence the desire to look for examples further back in time. No ice shelf setting is the same, but the researchers say their findings from the former British-Irish ice sheet could help understand how Antarctica might respond to today's rapidly warming climate. By looking at the changing scratch marks on the seafloor, the researchers discovered an abrupt shift in Britain's icebergs about 18,000 years ago, a time when the planet was gradually warming from a very cold period. The occasional production of giant bergs ceased. Instead, smaller ones were produced much more frequently. That indicates that the ice shelves suddenly disintegrated; without these massive floating platforms, such large icebergs could no longer be produced. And it's potentially important because this coincides with the time when the glaciers behind began to retreat faster and faster. The crucial, but unresolved, question is whether the disintegration of Britain's former ice shelves was merely a symptom of a quickly melting ice sheet - or whether the loss of these shelves directly triggered the runaway retreat of ice. Resolving this chicken-and-egg dilemma, as Dr Kirkham put it, would shed light on how serious the impacts of losing today's Antarctic ice shelves might be. "These ocean records are fascinating and have implications for Antarctica, as they illustrate the fundamental role of ice shelves in buttressing [holding back] the flow of continental ice into the ocean," said Prof Eric Rignot, glaciologist at the University of California, Irvine, who was not involved in the study. "But the argument that the collapse of ice shelves triggered ice sheet collapse is only part of the story; the main forcing is warmer air temperature and warmer ocean temperature," he argued. Graphics by Erwan Rivault
First evidence of city-sized icebergs found off UK coast
TruthLens AI Suggested Headline:
"Research Reveals Evidence of City-Sized Icebergs Off UK Coast"
Bbc News
8.1
TruthLens AI Summary
Recent research has revealed the existence of city-sized icebergs off the coast of the UK, providing the first definitive evidence that the ice sheet which once covered Britain and Ireland produced such massive ice formations. Scientists discovered distinctive scratch marks on the North Sea floor, which were created by these drifting icebergs over 18,000 years ago. The findings, published in the journal Nature Communications, are significant for understanding past climatic conditions and their implications for contemporary climate change. Using advanced 3D seismic data previously collected by oil and gas companies, researchers analyzed the sediment layers beneath the seafloor, revealing deep comb-like grooves attributed to the keels of enormous icebergs that calved from the British-Irish ice sheet. These icebergs, estimated to be between five to tens of kilometers wide and 50 to 180 meters thick, would have been comparable in size to medium-sized UK cities such as Norwich or Cambridge.
The research highlights the critical role of ice shelves in stabilizing glaciers and influencing sea level rise. As the planet warmed from a glacial period, the formation of giant icebergs ceased, indicating a drastic change in the ice shelf dynamics. This transition suggests that the loss of ice shelves could have triggered a rapid retreat of the glaciers behind them. The study raises important questions regarding the relationship between ice shelf disintegration and ice sheet retreat, which is crucial for predicting future sea level rise. While the research underscores the impact of warmer air and ocean temperatures on ice stability, it also emphasizes the need to understand the historical context of ice shelf behavior to better anticipate the effects of ongoing climate change. As experts continue to investigate these ancient ice formations, the findings could provide valuable insights into the future of Antarctica's ice and its global implications.
TruthLens AI Analysis
The article presents a significant scientific discovery regarding ancient icebergs off the UK coast, suggesting a historical context for understanding current climate phenomena. By revealing the existence of city-sized icebergs, the research highlights the impact of past glacial activity on the North Sea, linking historical climate conditions to present-day climate change discussions.
Purpose of Publication
The intention behind publishing this article seems to be to inform the public about important scientific findings that connect historical events to contemporary climate issues. By presenting this research, the authors aim to raise awareness about the implications of climate change on polar regions today. The discovery of such large icebergs provides a tangible reference point that can help the public grasp the scale of climatic changes over millennia.
Public Perception
This news could shape public perception by fostering a sense of urgency regarding climate change. The idea of city-sized icebergs might evoke concerns about rising sea levels and the potential for extreme weather events resulting from climate shifts. It emphasizes that climate change is not a distant issue but a fundamental reality with historical roots.
Information Concealment
While the article focuses on the scientific breakthrough, it does not delve into the potential socio-political implications of climate change or the ongoing debates about climate policies. There might be an underlying motive to avoid discussing contentious issues that could distract from the scientific narrative.
Manipulative Elements
The article does not overtly display manipulative language; however, it uses evocative imagery of city-sized icebergs to create a sense of awe and urgency. This choice of language may guide readers toward a particular emotional response, encouraging them to consider the implications of climate change more seriously.
Reliability of Information
The reliability of the article stems from its basis in scientific research published in a reputable journal. The findings are presented by credible experts, enhancing the article's trustworthiness. However, the interpretation of historical data can be subject to debate, suggesting that while the article is based on factual research, the conclusions drawn may still invoke further discussion within the scientific community.
Societal Impact
The implications of this discovery could lead to increased public interest in climate science, potentially influencing educational programs and policy discussions. As awareness grows, there may be a push for more proactive measures to address climate change, impacting both governmental and corporate strategies.
Target Audiences
The article is likely to resonate with environmentalists, scientists, and educators, as well as the general public concerned about climate change. It appeals to those interested in the intersection of history and science, particularly in the context of environmental issues.
Economic Repercussions
While the article may not have direct implications for stock markets or specific investments, it could influence sectors related to climate technology and renewable energy as public interest and demand for sustainable solutions increase. Companies involved in environmental research or climate adaptation strategies might see heightened interest from investors.
Geopolitical Relevance
The findings could contribute to discussions about climate change's global impact, especially concerning ice melting in polar regions. This research connects to broader geopolitical dialogues about climate agreements and international cooperation in addressing climate change challenges.
Potential AI Influence
Although it's unclear if AI was involved in the writing, models could have influenced the article's style or structure. If AI were used, it might have streamlined data presentation or assisted in generating accessible explanations of complex scientific concepts, framing the narrative in a way that engages a broader audience.
Conclusion
In summary, this article serves as a vital piece of scientific communication, shedding light on historical climate phenomena while urging contemporary society to reflect on the ongoing climate crisis. Its reliability is backed by credible research, though its emotional framing may lead to varying interpretations among readers.