Latest news with #EasternOman
Yahoo
5 days ago
- Science
- Yahoo
Geologists Accidentally Found a Ghost Plume Rising From Earth's Mantle
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Here's what you'll learn when you read this story: Mantle plumes are important geologic processes—they interact with plate tectonics, create rich mineral deposits, and even contribute to mass extinction events. Now, a new study has found evidence of a 'ghost plume'—a mantle plume that shows no sign of volcanic activity on the surface—under eastern Oman. Understanding these ghost plumes, and especially developing ways to find more of them, will help geologists better understand how much heat is escaping the core-mantle boundary. Mantle plumes are one of the most dynamic geologic processes on Earth. As their name suggests, these plumes move hot rock near the core-mantle boundary toward the surface, creating new landmasses (such as Hawai'i) or causing powerful geothermal activity (Yellowstone). Of course, moving all that magma beneath the Earth comes with a healthy dose of volcanism for those who live above these mantle superhighways—unless you live in Oman, that is. In a new paper published in the journal Earth and Planetary Science Letters, an international team of scientists—led by seismologist Simone Pilia of King Fahd University of Petroleum and Minerals in Saudi Arabia—claims to have found an amagmatic mantle plume, also known as a 'ghost plume,' resting beneath eastern Oman. Speaking with New Scientist, Pilia said that he accidentally discovered the plume while analyzing seismic data from the region. Seismologists typically analyze the interior of Earth using earthquake data from around the world. When an earthquake occurs, it sends seismic waves through the planet, and the trajectory of those waves can give scientists insight into the interior of the globe. While analyzing some of these waves, Pilia noticed a cylindrical area beneath eastern Oman where they moved more slowly and the rock they moved through appeared to be less rigid. This means that temperatures were much higher in this region, indicating the presence of a mantle plume. But eastern Oman doesn't display the surface volcanism that's typical of such areas. Taking a closer look with independent measurements, Pilia confirmed that a mantle plume—nicknamed 'Dani' after his son—likely existed roughly 660 kilometers below the surface. 'The more we gathered evidence, the more we were convinced that it is a plume,' Pilia told New Scientist. Although there is no volcanic activity on the surface above this plume, there are other pieces of evidence that point to some sort of geologic anomaly in the region. For example, Oman continues to rise in elevation long after the impacts of tectonic compression—a process that squeezes the Earth's crust together. The plume's existence also fits nicely into models detailing the movement of the Indian tectonic plate during the late Eocene. If this 'Dani plume' truly is a ghost plume, it would be the first one ever detected, and could possibly lead scientists to re-examine just how much heat is moving from the core-mantle boundary—especially if more ghost plumes exist around the world. Not only could that change Earth's geologic history, but mantle plumes provide many real-world benefits. They initiating seafloor spreading; they serve as sources of large nickel, platinum, and diamond deposits; and they can even cause global mass extinction events. If a variety of 'ghost plumes' are also at work around the world, it's important that we learn as much as we can. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Daily Mail
18-06-2025
- Science
- Daily Mail
Scientists spot a mysterious 'ghost plume' in Oman – and it suggests Earth's core could be LEAKING
A mysterious 'ghost plume' has been spotted beneath eastern Oman. Emanating from the Earth's core, this hot pillar of soft rock is pushing upwards from 410 miles (660km) beneath the planet's surface. Until now, the ghost plume was hidden because it hadn't broken through the surface to form volcanoes. But, in a new study, researchers have proved the 'ghost plume' exists by looking at how it slows down passing earthquake waves. Since waves move slower through hot, soft rock, this is a key sign that there is a plume hidden beneath the surface. Having shown that one ghost pillar exists, the researchers say there might be many more waiting to be found around the world. Worryingly , that might mean the Earth's core is leaking heat faster than scientists previously thought. Lead author Dr Simone Pilia, of the King Fahd University of Petroleum, Engineering and Geosciences, told MailOnline: 'It's a reminder that surface silence doesn't mean the mantle is quiet.' Ghost plumes are a type of mantle plume, pillars of hot rock which form when heat wells up from the boundary of the Earth's outer core, some 1,800 miles (2,890 km) beneath the surface. These are usually easy to find because they produce lots of volcanic activity at the surface as the molten rock is forced upwards. Dr Pilia says: 'A ghost plume is a mantle plume that doesn't produce observable surface volcanism, making it essentially "invisible" to traditional geological observation.' Although there are no volcanoes in Oman, Dr Pilia noticed that seismic waves from earthquakes slow down as they travel through this area. By analysing the way these waves were warped, Dr Pilia, who named the feature 'Dani' after his son, realised that there might be a cylinder of hot rock hidden beneath the ground. Dr Pilia and his co-authors used geological evidence and computer simulation to show how the presence of a mantle plume fits with what geologists already know about the area. Together, this evidence created a strong case that there is an elusive ghost plume lurking underground. Dr Pilia says: 'Despite lacking surface volcanic activity, all the deep-Earth signals of the plume are there.' Normally, mantle plumes would emerge at the surface as volcanoes. But Oman is above a layer of thick rock which keeps the plume well below the surface which it can't melt through Five layers of Earth Crust: To a depth of up to 43 miles (70km), this is the outermost layer of the Earth, covering both ocean and land areas. Mantle: Going down to 1,795 miles (2,890km) with the lower mantle, this is the planet's thickest layer and made of silicate rocks richer in iron and magnesium than the crust overhead. Outer core: Running to a depth of 3,200 miles (5,150km), this region is made of liquid iron and nickel with trace lighter elements. Inner core: Going down to a depth of 3,958 miles (6,370km) at the very centre of Earth, this region is thought to be made of solid iron and nickel. Innermost core: Within the inner core, this region is solid iron in a different, but unknown structure to the inner core. Based on this evidence, the plume is likely to be a cylinder around 125 to 185 miles in diameter (200-300km) and extends at least 410 miles (660km) deep. The rocks within the plume are up to 300°C (540°F) hotter than the surrounding mantle. Although these rocks are extremely hot, the researchers say the plume isn't producing volcanic activity due to a 'lid' of rock near the surface. Unlike above many other plumes, this 60-mile-thick (100km) layer of rock prevents the plume from melting its way to the surface. Dr Pilia says: 'Even if the plume is hot - and our data suggest it is - the pressure at those depths makes it very hard for melt to form and reach the surface. So, the plume exists, but it's essentially trapped.' Luckily for the people of Oman, Dr Pilia says this means the plume is 'very unlikely' to produce any volcanic activity in the foreseeable future. According to the modelling, the plume has been there for at least 40 million years, during which time it affected the drift of the Indian continental plate. The plume may also explain why parts of Oman continue to rise even after tectonic compression, a process which squeezes the Earth's crust together, has stopped. The researchers' modelling (pictured) suggests that the plume is a cylinder around 125 to 185 miles in diameter (200-300km) extending at least 410 miles (660km) beneath the surface Most importantly, this discovery also suggests that there may be many other ghost plumes out there waiting to be discovered, especially under areas with thick rock caps. That would mean more heat is leaking from the Earth's core than researchers previously thought, which could have big implications for the study of Earth's inner layers. Mantle plumes are a key part of how the Earth distributes heat and pressure deep beneath the surface. Studies have shown that they are closely linked to plate tectonics, the planet's magnetic field, and even the evolution of life on Earth. Dr Pilia says there are 'likely' many more ghost plumes around the world but these may be small and hard to spot without special networks of seismic detectors. 'What makes the Dani plume stand out is that we had just the right data, in just the right place, to finally see it. 'It's a reminder that surface silence doesn't mean the mantle is quiet.' The Earth is moving under our feet: Tectonic plates move through the mantle and produce Earthquakes as they scrape against each other Tectonic plates are composed of Earth's crust and the uppermost portion of the mantle. Below is the asthenosphere: the warm, viscous conveyor belt of rock on which tectonic plates ride. Earthquakes typically occur at the boundaries of tectonic plates, where one plate dips below another, thrusts another upward, or where plate edges scrape alongside each other. Earthquakes rarely occur in the middle of plates, but they can happen when ancient faults or rifts far below the surface reactivate.
