Latest news with #volcaniceruptions
Daily Mail
20 hours ago
- Science
- Daily Mail
Mysterious blobs deep inside Earth may fuel deadly volcanic eruptions - with the capability of wiping out life as we know it
Explosive volcanic eruptions don't just damage property and cancel flights. They can kill hundreds or even thousands of people, burying them under lethal 'pyroclastic' flows. Now, scientists in Australia have identified a possible cause of gigantic volcanic eruptions – mysterious 'blobs' about 1,200 miles under our feet. Blobs are three-dimensional regions that span the length of continents and stretch 100 times higher than Mount Everest. They sit at the bottom of Earth's rocky mantle above the molten outer core – a place so deep that Earth's elements are squeezed beyond recognition. And they're a starting point for plumes of hot molten rock which flow upwards towards the Earth's surface. There they erupt as lava, gases and rock fragments – with the capability of wiping out life as we know it. The authors warn that giant, large-scale eruptions can have serious impacts, such as sudden climate change and mass extinction events. Volcanic eruptions can intensify global warming by adding greenhouse gases such as carbon dioxide (CO2) to the atmosphere. Giant volcanoes also triggered events that led to the largest mass dying on Earth, the Permian-Triassic extinction 252 million years ago. 'These blobs have possibly existed for hundreds of millions of years,' say the researchers from the University of Wollongong near Sydney. Earth is made up of three layers – the crust, the mantle and the core, which was recently separated into 'inner' and 'outer'. According to the team, blobs are at the bottom of Earth's mantle, about 1,200 miles and 1,800 miles (2,000km and 3,000km) below our feet. The mantle, the planet's thickest layer, is predominantly a solid rock – but blobs may be different compared with the surrounding mantle rocks. Blobs are made of rock just like the rest of the mantle, but they're thought to be hotter and heavier. For their study, the team used computer modeling to simulate 'mantle convection' – the movement of material in Earth's mantle powered by heat – over one billion years. Blobs, which are some 1,200 miles below Earth's surface, move over time and are connected to Earth's surface by 'mantle plumes' that create giant eruptions How do scientists know about Earth's interior? No one can see inside the Earth, nor can drill deep enough to take rock samples from the mantle, the layer between Earth's core and crust. So geophysicists use indirect methods to see what's going on deep beneath our feet. For example, they use seismograms, or earthquake recordings, to determine the speed at which earthquake waves propagate. They then use this information to calculate the internal structure of the Earth - similar to how doctors use ultrasound to see inside the body. Their findings suggest that mantle plumes – columns of hot molten rock in the mantle – rise up from the continent-sized blobs. Mantle plumes are shaped a bit like a lollipop sticking upwards – with the 'stick' the plume tail and the 'candy' nearer Earth's surface the plume head. The researchers found that locations of volcanic eruption fall either onto (or close to) the location of blobs, as predicted by their models. This suggests that blobs – an acronym standing for Big LOwer-mantle Basal Structures – are essentially the deep-Earth origin of volcanic eruptions. Typically, deep Earth motions are in the order of 0.4-inch (1 cm) per year, so they only become significant over tens of millions of years. Blobs probably shift in a year at roughly the rate at which human hair grows each month, the team say. Although they have possibly existed for hundreds of millions of years, it's unclear what causes their movement. Mantle plumes rise very slowly from blobs through the mantle because they transport hot solid rock, not melt or lava. Cotopaxi, one of the highest active volcano in the world, stands at 19,347 feet (5,897 metres). Historically, its activity started in 1534 when the Spanish conquistadors began to venture into the territories that are now Ecuador At lower pressures in the uppermost 125 miles (200 km) of Earth's mantle, the solid rock melts, leading to volcanic eruptions. 'We used statistics to show that the locations of past giant volcanic eruptions are significantly related to the mantle plumes predicted by our models,' explain the authors in a piece for The Conversation. 'This is encouraging, as it suggests that the simulations predict mantle plumes in places and at times generally consistent with the geologic record.' The new findings, published in Communications Earth and Environment, suggest that the deep Earth is even more dynamic than we realised. Future research aims to explore the chemical nature of blobs, which might be possible with simulations that track the evolution of their composition. HOW CAN RESEARCHERS PREDICT VOLCANIC ERUPTIONS? According to Eric Dunham, an associate professor of Stanford University's School of Earth, energy and Environmental Sciences, 'Volcanoes are complicated and there is currently no universally applicable means of predicting eruption. In all likelihood, there never will be.' However, there are indicators of increased volcanic activity, which researchers can use to help predict volcanic eruptions. Researchers can track indicators such as: Volcanic infrasound: When the lava lake rises up in the crater of an open vent volcano, a sign of a potential eruption, the pitch or frequency of the sounds generated by the magma tends to increase. Seismic activity: Ahead of an eruption, seismic activity in the form of small earthquakes and tremors almost always increases as magma moves through the volcano's 'plumbing system'. Gas emissions: As magma nears the surface and pressure decreases, gases escape. Sulfur dioxide is one of the main components of volcanic gases, and increasing amounts of it are a sign of increasing amounts of magma near the surface of a volcano. Ground deformation: Changes to a volcano's ground surface (volcano deformation) appear as swelling, sinking, or cracking, which can be caused by magma, gas, or other fluids (usually water) moving underground or by movements in the Earth's crust due to motion along fault lines. Swelling of a volcano cans signal that magma has accumulated near the surface.
Yahoo
a day ago
- Science
- Yahoo
Mysterious Blobs Deep Inside Earth May Fuel Deadly Volcanic Eruptions
Volcanic eruptions can destroy essential infrastructure, ground air traffic for days, wipe out entire cities, disrupt the climate for years, and even wipe out life on Earth, so it's important to know what causes them to blow. New research has revealed that specific features deep within Earth can be linked directly to such cataclysmic eruptions. Thousands of kilometers below Earth's surface, there is a solid layer of hot rock called the lower mantle. Textbook diagrams would have you believe this is a smooth layer, but the lower mantle actually contains a mountainous topography, with two continent-sized structures, possibly made of different materials than their surrounds. Related: These hidden structures feature craggy ranges that shift and buckle much like the tectonic plates far above them. Volcanologist Annalise Cucchiaro from the University of Wollongong in Australia and her colleagues have found these big lower-mantle basal structures – termed 'BLOBS' by the research team – have a direct influence on volcanic activity at Earth's surface. When scorching columns of rock, known as deep mantle plumes, first rise from depths of nearly 3,000 kilometers (almost 2,000 miles), we get the kinds of Earth-shattering volcanoes that wiped out most of life on Earth, and had a hand in the extinction of the dinosaurs. The BLOBS seemed a likely source of these subterranean plumes, and Cucchiaro's team has now confirmed this connection using three different datasets that provide extensive detail on large volcanic eruptions that happened around 300 million years ago. "This work highlights the importance of mantle plumes in acting as 'magma highways' to the surface, creating these giant eruptions," Cucchiaro says. "It also shows that these plumes move along with their source, the BLOBS." There are two BLOBS within the lower mantle. One is below the African hemisphere, and the other, under the Pacific. We still don't know if the BLOBS are ever fixed in place, or if they're always moving around via convection, but the new research suggests it's a dynamic system with direct repercussions for us surface dwellers. By simulating the movements of BLOBS 1 billion years ago, the team showed that they produced mantle plumes that were sometimes slightly tilted as they rose. This meant eruptions occurred either directly above the BLOBS, or close to it – and these locations matched that of known eruptions. "We used statistics to show that the locations of past giant volcanic eruptions are significantly related to the mantle plumes predicted by our models," Cucchiaro and her colleague, geoscientist Nicholas Flament, explained in The Conversation. "This is encouraging, as it suggests that the simulations predict mantle plumes in places and at times generally consistent with the geologic record." As much as they destroy, large eruptions also have the power to create, and knowing where they may occur – either historically or in the future – could also help us to find magmatic treasures like kimberlite and diamonds, and minerals that could be used in harnessing renewable energy. "This research cracks open one of the questions that has long plagued scientists – are the BLOBS stationary or mobile and how do they relate to giant volcanic explosions – so it is a thrill to finally [be able] to unravel these mysteries," says Flament. This research was published in Communications Earth & Environment. Atlantic Ocean's Nanoplastic Problem Revealed in Shocking New Study Scientists Discovered This Amazing Practical Use For Leftover Coffee Grounds Antarctica's Ocean Is Mysteriously Getting Saltier, Spelling End to Sea Ice
Yahoo
3 days ago
- Science
- Yahoo
Horrifying Research Finds Melting Glaciers Could Activate Deadly Volcanoes
Scientists are warning that glaciers melting due to global warming could trigger explosive — and potentially deadly — volcanic eruptions around the world. As detailed in a new study presented at the Goldschmidt international geochemistry conference this week and due to be peer-reviewed later this year, researchers from the University of Wisconsin-Madison analyzed six volcanoes in southern Chile to study how retreating ice sheets may have influenced past volcanic behavior. Using advanced argon dating and crystal analysis methods, they found that around the peak of the last ice age, around 20,000 years ago, a thick ice cover subdued volcanic activity, allowing a huge reservoir of magma to accumulate six to nine miles below the surface. However, the end of the ice age led the ice sheets to retreat rapidly. The sudden loss of ice weight allowed gases in the magma to expand, setting the stage for explosive eruptions from newly formed volcanoes. Now, scientists are warning that a similar scenario could unfold thanks to global warming. "Glaciers tend to suppress the volume of eruptions from the volcanoes beneath them," said University of Wisconsin-Madison graduate student and lead author Pablo Moreno-Yaeger in a statement. "But as glaciers retreat due to climate change, our findings suggest these volcanoes go on to erupt more frequently and more explosively." Scientists previously found that melting glaciers could increase volcanic activity by observing the phenomenon in Iceland. However, other places in the world could also be at risk. "Our study suggests this phenomenon isn't limited to Iceland, where increased volcanicity has been observed, but could also occur in Antarctica," Moreno-Yaeger explained. "The key requirement for increased explosivity is initially having a very thick glacial coverage over a magma chamber, and the trigger point is when these glaciers start to retreat, releasing pressure — which is currently happening in places like Antarctica." "Other continental regions, like parts of North America, New Zealand and Russia, also now warrant closer scientific attention," he added. Worse, in the long term eruptions themselves could contribute to "long-term global warming because of a buildup of greenhouse gases," as Moreno-Yaeger explained. "This creates a positive feedback loop, where melting glaciers trigger eruptions, and the eruptions in turn could contribute to further warming and melting," he said. More on volcanoes: Scientists Say Something Is Corking the Yellowstone Supervolcano
The Guardian
4 days ago
- The Guardian
‘I'm here': Montserrat 30 years on from devastating volcanic eruption
This year marks the 30th anniversary of the volcanic eruptions that devastated the small Caribbean island of Montserrat. In July 1995, the Soufrière Hills volcano erupted for the first time in centuries, leaving 80% of the self-governing British overseas territory uninhabitable. Soufrière Hills, exclusion zone, Montserrat, 2024 The area known as the exclusion zone is now deserted and overgrown. The eruptions forced a mass exodus, depopulating the island from 14,000 to just over 4,000 people and rendering it one of the world's least populous sovereign states or dependencies. Those who stayed migrated north while Brades, once countryside, became Montserrat's de facto capital. The sense of what could have been permeates the island. Montserratians – including Alvin Ryan, the director of the Disaster Management Coordination Agency – are proud of the island's heyday. The holder of the proverbial and literal keys to the exclusion zone, Ryan speaks wistfully about a nation once on the precipice of independence, priding itself on its economic sustainability – exporting agricultural produce to neighbouring islands – and a robust musical and cultural identity. Shanna Johnson and Sheviyona Thomas take a break from the Miss Montserrat pageant opening ceremony at Carnival City, Little Bay As we drive into the boundaries of the exclusion zone, Ryan radios the Montserrat Volcano Observatory to announce our arrival – 'Two souls, one vehicle' – emphasising just how secure this area truly is. Once inside, he reminisces about his past life, from boiling eggs in the volcanic hot springs as a child, to believing in the myth of a beautiful mermaid living at the peak of the mountain, unaware then that it was an active volcano. There is an implicit kinship with those who hail from the same village in the old Montserrat or 'town' as it is affectionately called. This is what binds them – shared fond memories of belonging, flickered with grief. The interior of a dilapidated building, filled with ash in Plymouth – the centre of the exclusion zone Alvin Ryan in front of the supermarket he was in on the day of the first eruption in 1995 While we admire the scope of Soufrière Hills, Ryan's radio crackles with the voice of Montserrat's then governor, Sarah Tucker, imploring us to leave the zone immediately because of volcanic activity. We jog back to our vehicle. 'I always park my truck facing the exit in case I have to leave quickly,' says Ryan, crystallising the realities of life in the shadow of an active volcano. Despite this risk, a recently introduced government incentive is offering returning nationals duty-free concessions on materials to rebuild or fix abandoned homes in Cork Hill, an area on the periphery of the exclusion zone. This incentive is part of a wider governmental drive towards capital development and ecotourism, including a new seaport to accommodate bigger cruise ships and super-yachts. Allyaha entertains her little cousin outside their home in Davy Hill Even with this potential to increase economic activity on the island, Alford Dyett II, a young architect who splits his time between London and Montserrat, has his doubts. 'At some point there's not going to be enough people to sustain this country and we're getting very close,' he says. 'The people won't say it, the British government won't say it … a lack of population might be a reason why we have [low] crime and a great sense of community … but within this tranquillity we have no economy. We have a population crisis.' It is a catch-22 situation. Foreign investment can increase job opportunities, which are scarce (many young people feeling compelled to leave the island after secondary school graduation). It can also intensify fear of potential economic exploitation. Miss Montserrat 2021 to 2024, Nia St Claire, watches the procession as she anticipates handing over the crown Those remaining in Montserrat often juggle multiple jobs to survive. This is the case for Nia St Claire, Miss Montserrat between 2021 and 2024, who has several customer service jobs to stay afloat. The exclusion zone is incredibly fertile because of volcanic nutrients in the soil, but local residents are unable to take advantage and farm on it. As a result, fresh produce is scarce. Those not growing their own produce are dependent on processed foods. 'There are major health issues on the island like high rates of cancer and diabetes because of these processed foods,' says John Osborne, Montserrat's minister of agriculture. In an effort to contribute to the food economy, groups of men defy boundaries by camping off grid for days or weeks to illegally hunt in the exclusion zone. With limited access for rescue vehicles and the prospect of being mauled by wild pigs, they are risking their lives to catch and sell their bounty. Beyond this, it seems to be a peaceful protest – a noble persistence to roam a land they feel is rightfully theirs. Young masqueraders prepare for their performance at the opening ceremony of Montserrat carnival in Carnival City, Little Bay 'Sometimes I spend more than two weeks out in the bush,' says one of the island's hunters, who has agreed to speak on condition of anonymity. 'I love it. It's beautiful. And people pay big money for hogs – alive or dead.' The hunters are an anomaly, since many Montserratians have never returned to their villages after having to evacuate. Carmelita Kirwan stands outside her home with her family 'I've never been back,' says Carmelita Kirwan, a mother of 13. 'I don't go past Caulk Hill.' Kirwan's youngest, Joshua, a member of the local masquerade group, dreams of gaining an overseas basketball scholarship. Her third youngest, Kenville, is a popular musician on the island. When Kirwan and I first meet she insists she is 'here' – 'I always have been. I'm here.' Her emphasis on the word seems to betray a desire to be witnessed so her existence is not overlooked or forgotten. 'I am Montserrat's history, and my children are too,' she says. 'I stay here, and I give Montserrat 13 children. They will carry it on. [I hope] that someday we will turn to some brightness.' Zeekee and his dog pause before descending into the valleys of Silver Hills Montserrat is grappling with this need to be remembered – a desire to move beyond a past shaped by natural disaster and British colonial rule. The quotidian is demanding, yet it is remarkable how much people have forged a new identity in the past 30 years. There is much to be proud of. It is more than resilience – it is fortitude. It is no wonder that hunting, easy communing on patios and bars, elegant pageantry and everyday family life add up to both a way of living and a quiet persistence of sorts. Montserratians are determined to remain on a land that has shaped its people, irrespective of how much of it they are able to inhabit.
The Independent
5 days ago
- Science
- The Independent
Scientists discover the ‘missing link' that causes giant volcanic eruptions
Volcanic eruptions at Earth's surface have significant consequences. Smaller ones can scare tourists on Mount Etna or disrupt air traffic. Giant, large-scale eruptions can have more serious impacts. One such event contributed to the demise of the dinosaurs 66 million years ago. Giant volcanoes also triggered events that led to the largest mass dying on Earth, the Permian–Triassic extinction 252 million years ago But what fuels a giant eruption, and how does it make its way to the surface from deep within the planet? In a new study published in Communications Earth and Environment, we show that columns of hot rock, which rise some 3,000 kilometres through Earth's mantle and cause giant eruptions, are connected to continent-sized source regions we call BLOBS. Hidden blobs within Earth BLOBS are hot regions at the bottom of Earth's mantle (between about 2,000km and 3,000km in depth) which might be composed of different material compared with the surrounding mantle rocks. Scientists have long known about these two hot regions under the Pacific Ocean and Africa. Geologist David Evans from Yale University suggested the acronym BLOBS, which stands for Big LOwer-mantle Basal Structures. These BLOBS have possibly existed for hundreds of millions of years. It is unclear whether they're stationary or if they move around as part of mantle motion (called convection). Mantle plumes were the implicit link in previous studies relating BLOBS to giant volcanic eruptions. Their shape is a bit like a lollipop: the 'stick' is the plume tail and the 'candy' is the plume head. Mantle plumes rise very slowly through the mantle because they transport hot solid rock, not melt or lava. At lower pressures in the uppermost 200km of Earth's mantle, the solid rock melts, leading to eruptions. A long-sought relationship In our new study, we simulated mantle convection from one billion years ago and found that mantle plumes rise from moving BLOBS and can sometimes be gently tilted. Giant volcanic eruptions can be identified by the volume of volcanic rocks preserved at Earth's surface. The ocean floor preserves detailed fingerprints of mantle plumes for the past 120 million years or so (there is not much seafloor older than that). Oceanic plateaus, such as the Ontong Java-Manihiki-Hikurangi plateau currently in the southwest Pacific Ocean, are linked to plume heads. In contrast, a series of volcanoes such as the Hawaii -Emperor seamount chain and the Lord Howe seamount chain are linked to plume tails. We used statistics to show that the locations of past giant volcanic eruptions are significantly related to the mantle plumes predicted by our models. This is encouraging, as it suggests that the simulations predict mantle plumes in places and at times generally consistent with the geologic record. Are BLOBS fixed or mobile? We showed that the considered eruption locations fall either onto or close to the moving BLOBS predicted by our models. Eruption locations slightly outside moving BLOBS could be explained by plume tilting. We represented fixed BLOBS with 3D images of Earth's interior, created using seismic waves from distant earthquakes (a technique called seismic tomography). One out of the four seismic tomographic models that we considered matched the locations of past giant volcanic eruptions, implying that the fixed BLOBS scenario cannot be ruled out for geologically recent times – the past 300 million years. One of the next steps for this research is to explore the chemical nature of BLOBS and plume conduits. We can do so with simulations that track the evolution of their composition. Our results suggest the deep Earth is dynamic. BLOBS, which are some 2,000km below Earth's surface, move hundreds of kilometres over time, and are connected to Earth's surface by mantle plumes that create giant eruptions. To take a step back and keep things in perspective: while deep Earth motions are significant over tens of millions of years, they are generally in the order of 1 centimetre per year. This means BLOBS shift in a year at roughly the rate at which human hair grows each month. Nicolas Flament is an Associate Professor and ARC Future Fellow in Environmental Futures, School of Science at the University of Wollongong.
