Latest news with #Gernon
Newsweek
2 days ago
- Science
- Newsweek
Beneath America, a Large Buried Heat Blob Is Moving
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. There's something large moving deep beneath New England. This is the conclusion of a new paper by researchers from the University of Southampton, England, who have been studying a mysterious patch of unusually hot rock below the Appalachian Mountains. This region—known as the Northern Appalachian Anomaly (NAA)—is some 200 miles wide and lies around 125 miles beneath the surface. According to the researchers, the anomaly is part of a slow-moving underground "mantle wave" triggered by tectonic events that happened more than 90 million years ago. "The 'mantle wave' refers to a newly-discovered chain reaction of convective instabilities in the mantle that begins when a continent starts to rift," paper author and Southampton geodynamicist professor Tom Gernon told Newsweek. "It's not a literal wave, but a progressive flow and deformation of mantle material that behaves like a wave in how it propagates." This surprising find is shaking up what geologists thought they knew about the eastern U.S.—a region long considered geologically stable—and may help explain why parts of the Appalachian Mountains have been gently rising for millions of years. What Exactly Is the Northern Appalachian Anomaly? Appalachian Mountains in northeastern North America. Appalachian Mountains in northeastern North America. University of Southampton Imagine taking a CT scan of the Earth. That's essentially what geologists did using seismic tomography, a technique that tracks how earthquake waves travel through different layers of the planet. What they found under New Hampshire was a huge, slow-moving blob of hot material. This kind of anomaly is typically seen near volcanoes or tectonic boundaries—but New England has neither. Originally, scientists thought the NAA might be caused by "edge-driven convection," a type of vertical stirring in the Earth's mantle caused when thick and thin crust meet. But that didn't fully explain why this hot zone sits far inland, beneath thick and ancient rock. A Drip from the Distant Past A bold new theory reimagines the NAA as a "Rayleigh–Taylor instability"—a geological term for when heavy, cold rock begins to sink into the hot, soft rock below, like molasses dripping into honey. This process forces hotter material to rise, forming a plume of heat beneath the surface. The twist? This "drip" may not have originated beneath New England at all. Instead, scientists now believe it began near the Labrador Sea, a site where North America began pulling away from Europe over 120 million years ago. As the continents split, stress fractured deep layers of rock, triggering convective instabilities—blobs of rock slowly dripping downward under gravity. Gernon explained: "As the continent stretches and begins to split, space opens up beneath the rift. That space is rapidly filled by an inflow of soft, flowing asthenosphere." (The asthenosphere is a semi-molten part of the Earth's upper mantle, beneath the tectonic crust.) "This sudden movement disturbs the edge of the continent's root, triggering a chain reaction. Much like falling dominoes, blobs of the root begin to drip downward one after another. "These 'drips' migrate inland over time, away from the rift. We think this same process might explain unusual seismic patterns beneath the Appalachians. The timing lines up perfectly. These "drips" move slowly—about 20 kilometers every million years—which matches perfectly with the NAA's current location and age. Not a Lone Hot Spot The NAA may be just one part of a larger chain. Further south, another underground heat anomaly—the Central Appalachian Anomaly (CAA)—may represent an earlier drip in this chain. That one likely dates back around 135 million years, consistent with the early stages of the Labrador Sea rift. Together, these anomalies form a "mantle wave": a hidden, progressive disturbance deep inside the Earth, slowly traveling westward like a chain reaction. This idea, pioneered by Gernon's team, is gaining traction in explaining elevated plateaus, seismic activity, and even past volcanism in areas once considered geologically "dead." Origin of the Northern Appalachian Anomaly. Origin of the Northern Appalachian Anomaly. University of Southampton What It Means for the Surface While the Northern Appalachian Anomaly lies deep underground, its presence could help explain some of the long-term uplift seen in parts of the Appalachian Mountains. However, the region's dry climate and low erosion rates suggest that not much visible change has occurred in recent geological time. Earlier convective instabilities—like those possibly linked to the Central Appalachian Anomaly—may have had a greater impact, contributing to the reshaping of the landscape millions of years ago. The pattern of these features suggests that such deep mantle processes may have occurred repeatedly, moving step by step inland over tens of millions of years. Because there's limited seismic data in northern areas like Newfoundland and the Gulf of St. Lawrence, it's still unclear whether more of these ancient "drips" exist along the same path. But their potential connection hints at a larger, hidden system of mantle activity beneath the eastern edge of North America. Do you have a tip on a science story that Newsweek should be covering? Do you have a question about the mantle? Let us know via science@ Reference Gernon et al. (2025). A viable Labrador Sea rifting origin of the Northern Appalachian and related seismic anomalies. Geology.
Mint
23-04-2025
- Science
- Mint
Another win for geology's Theory of Everything
Plate tectonics is geology's Theory of Everything. The realisation in the 1960s that Earth's crust is made of fragments called plates—and that these plates can grow, shrink and move around—explained the origins of mountain ranges, ocean trenches, volcanoes and earthquakes. It also explained why continents drift over the planet's surface and thus, from time to time, come together to form an all-embracing supercontinent. Mountain ranges, ocean trenches, volcanoes and earthquakes are, however, things that happen mainly where plates abut. Plate tectonics is not as good at explaining events and features elsewhere, particularly in continental interiors. These are often dominated by extensive highlands called plateaux, which differ in form from mountain ranges and are frequently bounded by giant escarpments. But, as he told the annual meeting of the American Association for the Advancement of Science in Boston, Tom Gernon of Southampton University thinks he can bring these puzzling geographical features into the ambit of plate tectonics as well. His team's calculations suggest they are caused by waves that ripple through Earth's mantle, the layer below the crust, when continents divide. They may even be responsible for some of the 'mini" mass extinctions which punctuate the fossil record. His work began with a different, more eye-catching question: explaining how diamonds are propelled to the surface. Diamonds are crystals of carbon compressed into that form by the high pressure found in the upper mantle. Those discovered at the surface have been carried there by unusual, explosive volcanoes called kimberlite pipes, which traverse the crust from bottom to top, erupting at ground level. Dr Gernon and his colleagues proposed that the rifting of continental plates sets in motion a slow-moving wave through the semi-liquid rock of the mantle. (Really slow-moving: they estimate it travels at about 15-20km per million years.) This wave of hot rock ablates the bottom of the crust, forming gas-charged magmas that erupt violently as kimberlite pipes. They then followed up this work by asking what other consequences their newly discovered waves might have. The answers, when they ran their model on a computer, were giant escarpments with plateaux behind them. These features were formed by a process known as isostatic rebound, in which the travelling wave removed the crust's underside, causing the rock above to rise, rather as a balloon rises when its crew jettison ballast. All this rapidly emerging highland will, though, be subject to immediate erosion. And that is where the extinctions come in. Really big extinctions, such as those at the end of the Permian and Cretaceous periods, have big, sudden causes (huge volcanic eruptions and collision with an asteroid respectively). But these are interspersed by numerous smaller catastrophes that particularly affect the oceans, and are associated with reduced levels of oxygen. This reduction of oxygen seems to happen because organic matter is being created in greater than normal quantities, and then decomposing, sucking that element out of the water. Dr Gernon thinks this is a result of pulses of erosion caused by plateau uplift fertilising the oceans with phosphorus. That causes life to bloom, increasing the amount of organic matter available for decomposition. He argues, in particular, that the pattern of these mini mass extinctions during the Jurassic and Cretaceous periods supports his hypothesis. It all, then, fits very nicely together. Geology's Theory of Everything continues successfully to defend its title. © 2025, The Economist Newspaper Limited. All rights reserved. From The Economist, published under licence. The original content can be found on
Telegraph
08-04-2025
- Science
- Telegraph
Mini Ice Age may have fuelled collapse of Roman Empire
A 'Little Ice Age' in the sixth century was so intense it may have been the 'primary driver' in the fall of the Roman Empire, scientists believe. Between 536AD and 547AD, three massive volcanic eruptions blocked out the Sun and ushered in a rapid period of cooling which saw average temperatures fall by several degrees. Researchers at the University of Southampton have found that the mini Ice Age was so intense that it moved rocks from Greenland to Iceland. The scientists found smooth rounded rocks known as 'cobbles' on the beaches of Iceland's west coast which must have been carried on icebergs from Greenland. It suggests that the cooling event sparked changes even more widespread and severe than previously thought, causing major climate upheavals in the northern hemisphere that probably played a pivotal role in the collapse of the Roman Empire. 'When it comes to the fall of the Roman Empire, this climate shift may have been the straw that broke the camel's back,' said Prof Tom Gernon, co-author of the new research and an earth science professor at the University of Southampton. 'The climate was particularly cold at the time – cold enough for icebergs to reach and noticeably impact the geology in Iceland,' Prof Gernon added. 'The Roman Empire was likely already in decline when the Little Ice Age began. However, our findings support the idea that climate change in the northern hemisphere was more severe than previously thought. 'Indeed, it may have been a primary driver of major societal change, rather than just one of several contributing factors.' The period of cooling, dubbed the Late Antique Little Ice Age, lasted around 200 to 300 years. It is known to have coincided with a period of widespread social unrest across Europe and Asia, which saw the Roman empire giving way to the Byzantine era. By that time, the Roman empire had shrunk to the Mediterranean and continued to decline because crop failures induced by the cold, famine and plague. As well as the Romans, the huge climate shift also saw Chinese dynasties falling as well as the Eastern Turkic empire. The new findings, published in the journal Geology, show that the climate disruption reached far into the North Atlantic Ocean. Experts had known that the beach rocks on Iceland's west coast did not belong there but were unsure where they had come from until they studied their age and composition. The team found that the rocks came from Greenland by analysing the age and composition of tiny zircon crystals. Zircon is one of the primary minerals used to determine the age of rocks. 'We knew these rocks seemed somewhat out of place because the rock types are unlike anything found in Iceland today, but we didn't know where they came from,' said Dr Christopher Spencer, associate professor at Queen's University in Kingston, Ontario, and lead author of the research. 'Zircons are essentially time capsules that preserve vital information including when they crystallised as well as their compositional characteristics. 'The combination of age and chemical composition allows us to fingerprint currently exposed regions of the Earth's surface, much like is done in forensics.' The team discovered that the age of the fragments spanned nearly 3 billion years, and were able to trace the rocks back to specific regions of Greenland. 'This is the first direct evidence of icebergs carrying large Greenlandic cobbles to Iceland,' added Dr Spencer. The rocks were once carved out of the landscape by glaciers on Greenland and would have become embedded in ice which was eventually set adrift as icebergs. The ice-rafted rocks were likely deposited during the seventh century, coinciding with a major climate shift when temperatures warmed and the ground slowly rebounded after the heavy ice sheets melted. Prof Gernon added: 'This timing coincides with a known major episode of ice-rafting, where vast chunks of ice break away from glaciers, drift across the ocean, and eventually melt, scattering debris along distant shores.'
Yahoo
08-04-2025
- Science
- Yahoo
Mini Ice Age may have fuelled collapse of Roman Empire
A 'Little Ice Age' in the sixth century was so intense it may have been the 'primary driver' in the fall of the Roman Empire, scientists believe. Between 536AD and 547AD, three massive volcanic eruptions blocked out the Sun and ushered in a rapid period of cooling which saw average temperatures fall by several degrees. Researchers at the University of Southampton have found that the mini Ice Age was so intense that it moved rocks from Greenland to Iceland. The scientists found smooth rounded rocks known as 'cobbles' on the beaches of Iceland's west coast which must have been carried on icebergs from Greenland. It suggests that the cooling event sparked changes even more widespread and severe than previously thought, causing major climate upheavals in the northern hemisphere that probably played a pivotal role in the collapse of the Roman Empire. 'When it comes to the fall of the Roman Empire, this climate shift may have been the straw that broke the camel's back,' said Prof Tom Gernon, co-author of the new research and an earth science professor at the University of Southampton. 'The climate was particularly cold at the time – cold enough for icebergs to reach and noticeably impact the geology in Iceland,' Prof Gernon added. 'The Roman Empire was likely already in decline when the Little Ice Age began. However, our findings support the idea that climate change in the northern hemisphere was more severe than previously thought. 'Indeed, it may have been a primary driver of major societal change, rather than just one of several contributing factors.' The period of cooling, dubbed the Late Antique Little Ice Age, lasted around 200 to 300 years. It is known to have coincided with a period of widespread social unrest across Europe and Asia, which saw the Roman empire giving way to the Byzantine era. By that time, the Roman empire had shrunk to the Mediterranean and continued to decline because crop failures induced by the cold, famine and plague. As well as the Romans, the huge climate shift also saw Chinese dynasties falling as well as the Eastern Turkic empire. The new findings, published in the journal Geology, show that the climate disruption reached far into the North Atlantic Ocean. Experts had known that the beach rocks on Iceland's west coast did not belong there but were unsure where they had come from until they studied their age and composition. The team found that the rocks came from Greenland by analysing the age and composition of tiny zircon crystals. Zircon is one of the primary minerals used to determine the age of rocks.'We knew these rocks seemed somewhat out of place because the rock types are unlike anything found in Iceland today, but we didn't know where they came from,' said Dr Christopher Spencer, associate professor at Queen's University in Kingston, Ontario, and lead author of the research. 'Zircons are essentially time capsules that preserve vital information including when they crystallised as well as their compositional characteristics. 'The combination of age and chemical composition allows us to fingerprint currently exposed regions of the Earth's surface, much like is done in forensics.' The team discovered that the age of the fragments spanned nearly 3 billion years, and were able to trace the rocks back to specific regions of Greenland.'This is the first direct evidence of icebergs carrying large Greenlandic cobbles to Iceland,' added Dr Spencer. The rocks were once carved out of the landscape by glaciers on Greenland and would have become embedded in ice which was eventually set adrift as icebergs. The ice-rafted rocks were likely deposited during the seventh century, coinciding with a major climate shift when temperatures warmed and the ground slowly rebounded after the heavy ice sheets melted. Prof Gernon added: 'This timing coincides with a known major episode of ice-rafting, where vast chunks of ice break away from glaciers, drift across the ocean, and eventually melt, scattering debris along distant shores.' Broaden your horizons with award-winning British journalism. Try The Telegraph free for 1 month with unlimited access to our award-winning website, exclusive app, money-saving offers and more.
The Independent
08-04-2025
- Science
- The Independent
New evidence suggests surprise reason behind fall of Roman Empire
Scientists have uncovered evidence that sheds light on a little-known ice age that may have contributed to the decline of the Roman Empire. "Unusual rocks," discovered in Iceland, are believed to have been carried by icebergs travelling from Greenland sometime between 540 and 800 AD. This period of intense, rapid cooling, known as the Late Antique Little Ice Age, coincided with the crumbling of Roman power. Researchers suggest this climatic shift may have been the final blow to the already weakened empire. The ice age is thought to have been triggered by three major volcanic eruptions, the resulting ash clouds blocking sunlight and causing a drop in global temperatures. A University of Southampton spokeswoman said: 'Historians have long debated the role of climatic cooling in the fall of the Roman empire. 'This new research strengthens the case that a brief but intense period of cooling may have kicked an already declining empire and played a key role in inciting the mass migrations that reshaped Europe in this period.' Tom Gernon, professor of earth science at the University of Southampton and co-author of the report, published in the journal Geology, said: 'When it comes to the fall of the Roman empire, this climate shift may have been the straw that broke the camel's back.' Dr Christopher Spencer, associate professor at Queen's University in Kingston, Ontario, Canada, and lead author of the research, said that the team, which also involved the Chinese Academy of Sciences in Beijing, analysed the age and composition of the rocks found on a raised beach terrace on Iceland's west coast He said: 'We knew these rocks seemed somewhat out of place because the rock types are unlike anything found in Iceland today, but we didn't know where they came from.' The analysis involved examination of tiny mineral crystals called zircons, locked inside the rocks, which enabled the team to pinpoint their source. The scientists were able to locate the source to specific regions of Greenland. Dr Spencer said: 'This is the first direct evidence of icebergs carrying large Greenlandic cobbles to Iceland.' Prof Gernon added: 'The fact that the rocks come from nearly all geological regions of Greenland provides evidence of their glacial origins. 'As glaciers move, they erode the landscape, breaking up rocks from different areas and carrying them along, creating a chaotic and diverse mixture, some of which ends up stuck inside the ice.' He said that the study showed that the 'ice-rafted' rocks were likely deposited during the 7th century. Prof Gernon said: 'This timing coincides with a known major episode of ice-rafting, where vast chunks of ice break away from glaciers, drift across the ocean, and eventually melt, scattering debris along distant shores.' Dr Spencer added: 'What we're seeing is a powerful example of how interconnected the climate system is. When glaciers grow, icebergs calve, ocean currents shift, and landscapes change. Climate-driven iceberg activity may have been one of the many cascading effects of rapid cooling.'
