Latest news with #volcanism
Yahoo
9 hours ago
- Science
- Yahoo
'Pulsing, like a heartbeat': Rhythmic mantle plume rising beneath Ethiopia is creating a new ocean
When you buy through links on our articles, Future and its syndication partners may earn a commission. Rhythmic pulses of molten rock are rising beneath eastern Africa, according to a new study. The pulsing plume of hot mantle beneath Ethiopia, driven by plate tectonics, is slowly pulling the region apart and forming a new ocean near the Gulf of Aden and the Red Sea, researchers reported June 25 in the journal Nature Geoscience. "We have found that the evolution of deep mantle upwellings is intimately tied to the motion of the plates above," Derek Keir, an Earth scientist at the University of Southampton and the University of Florence, said in a statement. "This has profound implications for how we interpret surface volcanism, earthquake activity, and the process of continental breakup." The mantle plume lies under Ethiopia's Afar region, at the intersection of three tectonic plates. All of the rifts between these plates are different ages, and they are changing at different rates; some are in the process of forming new oceans, while others are pulling apart the crust beneath Africa. But the structure and motion of the plume, as well as the forces driving these movements, aren't well understood. To investigate the structure of the crust and the mantle plume beneath it, the scientists studied the chemical compositions of more than 130 samples of volcanic rocks from the Afar region. These samples provided information about the depth and composition of melted rock beneath the surface. The team also used computer models to determine how the region might respond to different kinds of mantle plumes and compared those responses to existing geological data. A single mantle plume lies beneath all three rifts, the researchers found, but its chemical composition is not uniform. Further, the molten rock surges upward rhythmically, leaving behind distinct chemical signatures. "The chemical striping suggests the plume is pulsing, like a heartbeat," Tom Gernon, an Earth scientist at the University of Southampton, said in the statement. "These pulses appear to behave differently depending on the thickness of the plate, and how fast it's pulling apart. In faster-spreading rifts like the Red Sea, the pulses travel more efficiently and regularly like a pulse through a narrow artery." RELATED STORIES —Study reveals 'flawed argument' in debate over when plate tectonics began —There's a 'ghost' plume lurking beneath the Middle East — and it might explain how India wound up where it is today —Africa is being torn apart by a 'superplume' of hot rock from deep within Earth, study suggests Varying spacing between the stripes in different rifts suggests that the mantle plume responds differently depending on the tectonic plates above. In places where the lithosphere — the crust and upper mantle — is thicker, the mantle flow is impeded, and the striping is more condensed. Under a thinner lithosphere, the stripes are more spread out. The findings could help scientists understand volcanic activity at the surface. "The work shows that deep mantle upwellings can flow beneath the base of tectonic plates and help to focus volcanic activity to where the tectonic plate is thinnest," Keir said in the statement. Future work in the Afar region could involve investigating the rate of mantle flow beneath the various plates, Keir added.
Yahoo
3 days ago
- Science
- Yahoo
Earth Is Pulsing Beneath Africa Where The Crust Is Being Torn Apart
A deep, rhythmic pulse has been found surging like a heartbeat deep under Africa. At the Afar triple junction under Ethiopia, where three tectonic plates meet, molten magma pounds the planet's crust from below, scientists have discovered. There, the continent is slowly being torn asunder in the early formation stages of a new ocean basin. By sampling the chemical signatures of volcanoes around this region, a team led by geologist Emma Watts of Swansea University in the UK hoped to learn more about this wild process. "We found that the mantle beneath Afar is not uniform or stationary – it pulses, and these pulses carry distinct chemical signatures," says Watts, who was at the University of Southampton in the UK when the research was conducted. "These ascending pulses of partially molten mantle are channeled by the rifting plates above. That's important for how we think about the interaction between Earth's interior and its surface." Related: Our planet's surface is in a constant state of renovation. The tectonic plates into which the planetary crust is divided aren't fixed in position, but shift and collide and even slip underneath one another. The places at which they meet are usually hotspots of geological evolution, quite literally, rampant with volcanic activity that is reshaping the surface from below. The Afar junction is the point at which the Arabian, Nubian, and Somalian plates meet, each departing in their own directions to leave a widening gap under the Afar Triangle. Eventually, the crust will become so thin here that the surface will drop below sea level, creating a new ocean basin off the Red Sea. Scientists suspect that mantle upwelling is playing a role in this continental breakup process, but our understanding of how it works is limited. We can't exactly just dig down to have a close look, so Watts and her colleagues went for the next best thing: looking at material that has been disgorged onto Earth's surface from the mantle by way of volcano. They collected 130 samples of volcanic rock from around the Afar region and the Main Ethiopian Rift, and conducted chemical analyses. They used these analyses combined with existing data to conduct advanced modeling to understand what's going on with the activity under the Triangle. The results showed distinct chemical bands or stripes that repeat across the rift system, delivered by a single, asymmetrical plume of material shaped by its environment and pushing upwards from the mantle. "The chemical striping suggests the plume is pulsing, like a heartbeat," says geologist Tom Gernon of the University of Southampton in the UK. "These pulses appear to behave differently depending on the thickness of the plate, and how fast it's pulling apart. In faster-spreading rifts like the Red Sea, the pulses travel more efficiently and regularly like a pulse through a narrow artery." If the team's model is correct, it suggests that mantle plumes and upwellings can be shaped by the dynamics of the tectonic plates above them – a finding that could be used to inform future research into the activity that is continually remodeling our planet. "We have found that the evolution of deep mantle upwellings is intimately tied to the motion of the plates above. This has profound implications for how we interpret surface volcanism, earthquake activity, and the process of continental breakup," says geophysicist Derek Keir of the University of Southampton and the University of Florence in Italy. "The work shows that deep mantle upwellings can flow beneath the base of tectonic plates and help to focus volcanic activity to where the tectonic plate is thinnest. Follow-on research includes understanding how and at what rate mantle flow occurs beneath plates." The research has been published in Nature Geoscience. Strange Cellular Entity Challenges Very Definition of Life Itself Sharks Do Something Bizarre When Turned Upside Down, And We Don't Know Why Orcas' Strange Beauty Routine Revealed by Scientists For The First Time
Yahoo
4 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?
WIRED
15-06-2025
- Science
- WIRED
The Mysterious Inner Workings of Io, Jupiter's Volcanic Moon
Jun 15, 2025 7:00 AM Recent flybys of the fiery world refute a leading theory of its inner structure—and reveal how little is understood about geologically active moons. Photograph: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM The original version of this story appeared in Quanta Magazine. Scott Bolton's first encounter with Io took place in the summer of 1980, right after he graduated from college and started a job at NASA. The Voyager 1 spacecraft had flown past this moon of Jupiter, catching the first glimpse of active volcanism on a world other than Earth. Umbrella-shaped outbursts of magmatic matter rocketed into space from all over Io's surface. 'They looked amazingly beautiful,' said Bolton, who is now based at the Southwest Research Institute in Texas. 'It was like an artist drew it. I was amazed at how exotic it looked compared to our moon.' Scientists like Bolton have been trying to understand Io's exuberant volcanism ever since. A leading theory has been that just below the moon's crust hides a global magma ocean, a vast contiguous cache of liquid rock. This theory dovetails neatly with several observations, including ones showing a roughly uniform distribution of Io's volcanoes, which seem to be tapping the same omnipresent, hellish source of melt. But now, it appears that Io's hell has vanished—or rather, it was never there to begin with. During recent flybys of the volcanic moon by NASA's Juno spacecraft, scientists measured Io's gravitational effect on Juno, using the spacecraft's tiniest wobbles to determine the moon's mass distribution and therefore its internal structure. The scientists reported in Nature that nothing significant is sloshing about just beneath Io's crust. 'There is no shallow ocean,' said Bolton, who leads the Juno mission. Independent scientists can find no fault with the study. 'The results and the work are totally solid and pretty convincing,' said Katherine de Kleer, a planetary scientist at the California Institute of Technology. The data has reopened a mystery that spills over into other rocky worlds. Io's volcanism is powered by a gravity-driven mechanism called tidal heating, which melts the rock into magma that erupts from the surface. Whereas Io is the poster child for this mechanism, tidal heating also heats many other worlds, including Io's neighbor, the icy moon Europa, where the heat is thought to sustain a subterranean saltwater ocean. NASA launched the $5 billion Clipper spacecraft to search Europa's sky for signs of life in the proposed underground ocean. A map of Io's surface, created with images from the Voyager 1 and Galileo missions, shows the wide distribution of the moon's volcanoes. The large red ring is sulfurous fallout from the plume of the Pele volcano. Photograph: US Geological Survey But if Io doesn't have a magma ocean, what might that mean for Europa? And, scientists now wonder, how does tidal heating even work? Melting Magma Heat drives geology, the rocky foundation upon which everything else, from volcanic activity and atmospheric chemistry to biology, is built. Heat often comes from a planet's formation and the decay of its radioactive elements. But smaller celestial objects like moons have only tiny reserves of such elements and of residual heat, and when those reserves run dry, their geological activity flatlines. Or, at least, it should—but something appears to grant geologic life to small orbs throughout the solar system long after they should have geologically perished. Io is the most flamboyant member of this puzzling club—a burnt-orange, crimson, and tawny Jackson Pollock painting. The discovery of its over-spilling cauldrons of lava is one of the most famous tales in planetary science, as they were predicted to exist before they were discovered. NASA's Voyager 1 probe photographed Io in 1979, revealing the first glimpse of volcanism beyond Earth. In this photo mosaic, a lava plume is seen emanating from Loki Patera, now known to be the moon's largest volcano. Photograph: NASA/JPL/USGS On March 2, 1979, a paper in Science ruminated on Io's strange orbit. Because of the positions and orbits of neighboring moons, Io's orbit is elliptical rather than circular. And when Io is closer to Jupiter, it experiences a stronger gravitational pull from the gas giant than when it is farther away. The study authors figured that Jupiter's gravity must therefore be constantly kneading Io, pulling its surface up and down by up to 100 meters, and, per their calculations, generating a lot of frictional heat within it—a mechanism they described as 'tidal heating.' They conjectured that Io may be the most intensely heated rocky body in the solar system. 'One might speculate that widespread and recurrent surface volcanism would occur,' they wrote. Just three days later, Voyager 1 flew by. An image taken on March 8 documented two gigantic plumes arching above its surface. After ruling out all other causes, NASA scientists concluded that Voyager had seen an alien world's volcanic eruptions. They reported their discovery in Science that June, just three months after the prediction. The planetary science community quickly coalesced around the idea that tidal heating within Io is responsible for the never-ending volcanism on the surface. 'The unknown part that's been an open question of decades is what that means for the interior structure,' said Mike Sori, a planetary geophysicist at Purdue University. Where is that tidal heating focused within Io, and just how much heat and melting is it generating? Courtest of Mark Belan/Quanta Magazine NASA's Galileo spacecraft studied Jupiter and several of its moons around the turn of the millennium. One of its instruments was a magnetometer, and it picked up a peculiar magnetic field emanating from Io. The signal appeared to be coming from an electrically conductive fluid—a lot of fluid, in fact. After years of study, scientists concluded in 2011 that Galileo had detected a global magma ocean just below Io's crust. Whereas Earth's mantle is mostly solid and plasticky, Io's subsurface was thought to be filled with an ocean of liquid rock 50 kilometers thick, or almost five times thicker than the Pacific Ocean at its deepest point. A similar magnetic field was coming from Europa, too—in this case, apparently generated by a vast ocean of salty water. The implications were profound: With a lot of rocky material, tidal heating can make oceans of magma. With plenty of ice, it can create oceans of potentially habitable liquid water. Volcanic Vanishing Act By the time the Juno spacecraft started swinging around Jupiter in 2016, the belief that Io had a magma ocean was widespread. But Bolton and his colleagues wanted to double-check. A sequence of images taken over the course of eight minutes by NASA's New Horizons probe in 2007 shows an eruption by the Tvashtar Paterae volcanic region. The plume in this false-color image rises 330 kilometers from the moon's surface. Video: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute During flybys in December 2023 and February 2024, Juno came within 1,500 kilometers of Io's scorched surface. Although the remarkable images of active volcanoes drew everyone's attention, the goal of these flybys was to find out if a magma ocean truly lay beneath the moon's rocky skin. To investigate, the team used an unlikely tool: Juno's radio transponder, which communicates with Earth, sending and receiving signals. Because of Io's unevenly distributed mass, its gravitational field isn't perfectly symmetrical. That uneven gravitational field subtly alters the motion of Juno as it flies by, causing it to accelerate or decelerate a little. That means Juno's radio transmissions will experience the Doppler effect, where the wavelength shifts slightly in response to Io's uneven gravitational field. By looking at the incredibly small shifts in the transmissions, Bolton's team was able to create a high-fidelity picture of Io's gravitational field and use that to determine its internal structure. 'If there were indeed a global magma ocean, you'd see a lot more distortion as Io orbited around Jupiter and as the tidal forces flexed it and changed its shape,' said Ashley Davies, a volcanologist at NASA's Jet Propulsion Laboratory who wasn't involved with the new study. But Bolton's team did not find this level of distortion. Their conclusion was clear. 'There cannot be a shallow magma ocean fueling the volcanoes,' said study coauthor Ryan Park, a Juno co-investigator at the Jet Propulsion Laboratory. The Cassini-Huygens mission photographed Io against the backdrop of Jupiter in 2001. Photograph: NASA/JPL/University of Arizona So what else might be powering Io's volcanoes? On Earth, discrete reservoirs of magma of different types—from the tarlike viscous matter that powers explosive eruptions to the runnier, honey-esque stuff that gushes out of some volcanoes—are located within the crust at various depths, all created by the interactions of tectonic plates, the moving jigsaw pieces that make up Earth's surface. Io lacks plate tectonics and (perhaps) a diversity of magma types, but its crust may nevertheless be peppered with magma reservoirs. This was one of the original lines of thought until Galileo's data convinced many of the magma ocean theory. The new study doesn't rule out a far deeper magma ocean. But that abyssal cache would have to be filled with magma so iron-rich and dense (because of its great depth) that it would struggle to migrate to the surface and power Io's volcanism. 'And at some depth, it becomes tricky to distinguish between what we would call a deep magma ocean versus a liquid core,' Park said. For some, this raises an irreconcilable problem. Galileo's magnetometer detected signs of a shallow magma ocean, but Juno gravity data has emphatically ruled that out. 'People are not really disputing the magnetometer results, so you have to make that fit with everything else,' said Jani Radebaugh, a planetary geologist at Brigham Young University. Researchers disagree on the best interpretation of the Galileo data. The magnetic signals 'were taken as probably the best evidence for a magma ocean, but really they weren't that strong,' said Francis Nimmo, a planetary scientist at the University of California, Santa Cruz, and a coauthor of the new study. The induction data couldn't distinguish between a partly molten (but still solid) interior and a fully molten magma ocean, he said. Heavy Water Perhaps the main reason scientists study Io is because it teaches us about the fundamentals of tidal heating. Io's tidal heating engine remains impressive—there's clearly a lot of volcano-feeding magma being generated. But if it's not producing a subsurface magma ocean, does that mean tidal heating doesn't generate water oceans, either? Scientists remain confident that it does. Nobody doubts that Saturn's moon Enceladus, which is also tidally heated, contains an underground saltwater ocean; the Cassini spacecraft not only detected signs of its existence but directly sampled some of it erupting out of the moon's South Pole. And although there is some light skepticism about whether Europa has an ocean, most scientists think it does. The smooth, lightly scratched surface of Jupiter's icy moon Europa, photographed by the Juno spacecraft in 2022, shows no sign of what lies beneath: in all likelihood, a vast saltwater ocean. Photograph: NASA/JPL-Caltech/SwRI/MSSS Crucially, unlike Io's odd magnetic field, which seemed to indicate that it concealed an ocean's worth of fluid, Europa's own Galileo-era magnetic signal remains robust. 'It's a pretty clean result at Europa,' said Robert Pappalardo, the Europa mission's project scientist at the Jet Propulsion Laboratory. The icy moon is far enough from Jupiter and the intense plasma-flooded space environment of Io that Europa's own magnetic induction signal 'really sticks out.' But if both moons are tidally heated, why does only Europa have an inner ocean? According to Nimmo, 'there's a fundamental difference between a liquid-water ocean and a magma ocean. The magma wants to escape; the water really doesn't.' Liquid rock is less dense than solid rock, so it wants to rise and erupt quickly; the new study suggests that it doesn't linger at depth long enough inside Io to form a massive, interconnected ocean. But liquid water is, unusually, denser than its solid icy form. 'Liquid water is heavy, so it collects into an ocean,' Sori said. 'I think that's the big-picture message from this paper,' Sori added. Tidal heating might struggle to create magma oceans. But on icy moons, it can easily make watery oceans due to the bizarrely low density of ice. And that suggests life has a multitude of potentially habitable environments throughout the solar system to call home. Hell's Poster Child The revelation that Io is missing its shallow magma ocean underscores just how little is known about tidal heating. 'We've never really understood where in Io's interior the mantle is melting, how that mantle melt is getting to the surface,' de Kleer said. Our own moon shows evidence of primeval tidal heating too. Its oldest crystals formed 4.51 billion years ago from the stream of molten matter that got blasted off Earth by a giant impact event. But a lot of lunar crystals seem to have formed from a second reservoir of molten rock 4.35 billion years ago. Where did that later magma come from? Nimmo and coauthors offered one idea in a paper published in Nature in December: Maybe Earth's moon was like Io. The moon was significantly closer to Earth back then, and the gravitational fields from the Earth and the sun were battling for control. At a certain threshold, when the gravitational influence of both were roughly equal, the moon might have temporarily adopted an elliptical orbit and gotten tidally heated by Earth's gravitational kneading. Its interior might have remelted, causing a surprise secondary flourish of volcanism. But exactly where within the moon's interior its tidal heating was concentrated—and thus, where all that melting was happening—isn't clear. Perhaps if Io can be understood, so too can our moon—as well as several of the other satellites in our solar system with hidden tidal engines. For now, this volcanic orb remains maddeningly inscrutable. 'Io's a complicated beast,' Davies said. 'The more we observe it, the more sophisticated the data and the analyses, the more puzzling it becomes.' Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.
Forbes
27-05-2025
- Science
- Forbes
Superplume Beneath Continent Is Splitting Africa Apart
Aerial view of Suguta River in the Great Rift Valley. Kenya. Sophisticated chemical analysis of volcanic gases from Kenya have provided the first evidence that a superplume lies beneath East Africa driving active tectonics and slowly separating the Somali plate and the Horn of Africa from the rest of the continent. An international team of scientists led by Professor Fin Stuart from the University of Glasgow, working in partnership with the Kenya Geothermal Development Company, has discovered surprising results in a new study of gases from the Menengai geothermal field in central Kenya. The rift valleys of East Africa are some of the largest and most spectacular topographic features on Earth. They extend for 3,500 kilometers through Ethiopia, Kenya, Uganda and Malawi, and host extensive volcanic fields. The rifts are the manifestation of the African tectonic plate being split apart driven by forces in the Earth's interior. However, scientists are uncertain whether the volcanism and rifting is due to shallow processes or whether it is driven by up-welling hot material from Earth's mantle. As countries along the rift zone are tapping into geothermal energy, scientists get access to new sampling sites. The researchers used gases collected from the Menengai geothermal field (started in 2009 and still in development) in central Kenya to reconstruct the source in Earth's mantle feeding the geothermal activity. The team notes that the gases are chemically indistinguishable from gases present in volcanic rocks from Hawaiʻi', where volcanism is fueled by a mantle plume. Together with the common chemical 'fingerprint' between different geothermal fields— the researchers compared their results with gas samples coming from the Red Sea to the north and from Malawi to the south — this discovery supports the theory that a single "superplume" is the main source. 'Our research suggests that a giant hot blob of rock from the core-mantle boundary is present beneath East Africa," summarizes Stuart. The plume not only drives the tectonic plates apart, but also pushes up the African continent preventing the rift zone to be flooded by the Red Sea (forming the geologically spectacular landscapes of the Afar Depression). Map of East Africa showing some of the historically active volcanoes (red triangles) and the Afar ... More Depression (shaded, center). Seismic surveys indicate the presence of a large anomaly beneath the southern tip of the African continent. Such "Large Low Shear Velocity Provinces" are composed of hot and weak mantle material, and the only other similar anomaly lies beneath the Pacific Plate. They may be the primary source feeding the mantle plume of Hawai'i and the plume beneath Africa, explaining the identical chemical signatures as described by the researchers. The study,"Neon Isotopes in Geothermal Gases From the Kenya Rift Reveal a Common Deep Mantle Source Beneath East Africa," was published in the journal Geophysical Research Letters. Additional material and interviews provided by the University of Glasgow.
