Latest news with #tectonicPlates
Yahoo
2 days ago
- Science
- Yahoo
World-first: Slow-motion earthquake that travels miles in weeks captured, stuns scientists
Researchers from a renowned U.S. university captured a slow slip earthquake in motion. It was captured during the act of releasing tectonic pressure on a major fault zone at the bottom of the ocean. A team from the University of Texas at Austin recorded the slow earthquake spreading along the tsunami-generating portion of the fault off the coast of Japan, behaving like a tectonic shock absorber. The team described the event as the slow unzipping of the fault line between two of the Earth's tectonic plates.A type of slow-motion seismic event that takes days or weeks to unfold, slow slip earthquakes are relatively new to science and are thought to be an important process for accumulating and releasing stress as part of the earthquake cycle. The new measurements, made along Japan's Nankai Fault, appear to confirm that. "It's like a ripple moving across the plate interface," said Josh Edgington, who conducted the work as a doctoral student at the University of Texas Institute for Geophysics (UTIG) at UT Austin's Jackson School of captured the earthquake with the help of borehole sensors that were placed in the critical region far offshore, where the fault lies closest to the seafloor at the ocean Director Demian Saffer, who led the study, stressed that sensors installed in boreholes can detect even the slightest motions, as small as a few movement on the shallow fault is all but invisible to land-based monitoring systems such as GPS slow slip earthquake, captured by the team's sensors in the fall of 2015, traveled along the tail of the fault — the region close to the seafloor where shallow earthquakes can generate tsunamis, easing tectonic pressure at a potentially hazardous location. A second slow tremor in 2020 followed the same path."In this work, we analyze formation pore pressure records from three offshore borehole observatories at the Nankai subduction zone, Honshu, Japan, to capture detailed slip-time histories of two slow slip events (SSEs) along the outermost reaches of the plate boundary," said researchers in the results published in the journal Science recently."Slip initiates ~30 kilometers landward of the trench; migrates seaward at 1 to 2 kilometers per day to within a few kilometers of, and possibly breaching, the trench; and coincides with the onset and migration of tremor and/or very-low-frequency earthquakes. The SSE source region lies in a zone of high pore fluid pressure and low stress, which provides clear observational evidence linking these factors to shallow slow earthquakes." The two events, which have only now successfully been analyzed in detail, appear as ripples of deformation traveling through Earth's crust. Originating about 30 miles off the coast of Japan, borehole sensors tracked this unzipping motion along the fault as it moved out to sea before dissipating at the edge of the continental margin, according to a press also pointed out that although the Nankai Fault is known to generate large earthquakes and tsunamis, the discovery suggests that this part of the fault does not contribute energy to these events, acting more like a shock absorber. The results will help researchers home in on the behavior of subduction zone faults across the Pacific Ring of Fire, the tectonic belt that spawns the planet's largest earthquakes and tsunamis. Each event took several weeks to travel 20 miles along the fault, and each one happened in places where geologic fluid pressures were higher than normal. The finding is important because it is strong evidence that fluids are a key ingredient for slow earthquakes. This is an idea widely circulated in the scientific community, but finding a direct connection has been elusive until now, as per the also revealed that the last time Japan's Nankai Fault produced a significant earthquake was in 1946. The magnitude 8 earthquake destroyed 36,000 homes and killed over 1,300 people. Although another large earthquake is expected in the future, the observations suggest the fault releases at least some of its pent-up energy harmlessly in regular, recurring slow slip earthquakes. The team stressed that the location is also important because it shows that the part of the fault nearest the surface releases tectonic pressure independently of the rest of the these details, scientists can begin to probe other regions of the fault to better understand the overall hazard it poses. Saffer underlined that knowledge is also vital for understanding other faults.
The Independent
29-05-2025
- General
- The Independent
Scientists solve mystery of Antarctic mountain range hidden for 500 million years
Have you ever imagined what Antarctica looks like beneath its thick blanket of ice? Hidden below are rugged mountains, valleys, hills and plains. Some peaks, like the towering Transantarctic Mountains, rise above the ice. But others, like the mysterious and ancient Gamburtsev Subglacial Mountains in the middle of East Antarctica, are completely buried. The Gamburtsev Mountains are similar in scale and shape to the European Alps. But we can't see them because the high alpine peaks and deep glacial valleys are entombed beneath kilometres of ice. How did they come to be? Typically, a mountain range will rise in places where two tectonic plates clash with each other. But East Antarctica has been tectonically stable for millions of years. Our new study, published in Earth and Planetary Science Letters, reveals how this hidden mountain chain emerged more than 500 million years ago when the supercontinent Gondwana formed from colliding tectonic plates. Our findings offer fresh insight into how mountains and continents evolve over geological time. They also help explain why Antarctica's interior has remained remarkably stable for hundreds of millions of years. A buried secret The Gamburtsev Mountains are buried beneath the highest point of the East Antarctic ice sheet. They were first discovered by a Soviet expedition using seismic techniques in 1958. Because the mountain range is completely covered in ice, it's one of the least understood tectonic features on Earth. For scientists, it's deeply puzzling. How could such a massive mountain range form and still be preserved in the heart of an ancient, stable continent? Most major mountain chains mark the sites of tectonic collisions. For example, the Himalayas are still rising today as the Indian and Eurasian plates continue to converge, a process that began about 50 million years ago. Plate tectonic models suggest the crust now forming East Antarctica came from at least two large continents more than 700 million years ago. These continents used to be separated by a vast ocean basin. The collision of these landmasses was key to the birth of Gondwana, a supercontinent that included what is now Africa, South America, Australia, India and Antarctica. Our new study supports the idea that the Gamburtsev Mountains first formed during this ancient collision. The colossal clash of continents triggered the flow of hot, partly molten rock deep beneath the mountains. As the crust thickened and heated during mountain building, it eventually became unstable and began to collapse under its own weight. Deep beneath the surface, hot rocks began to flow sideways, like toothpaste squeezed from a tube, in a process known as gravitational spreading. This caused the mountains to partially collapse, while still preserving a thick crustal 'root', which extends into Earth's mantle beneath. Crystal time capsules To piece together the timing of this dramatic rise and fall, we analysed tiny zircon grains found in sandstones deposited by rivers flowing from the ancient mountains more than 250 million years ago. These sandstones were recovered from the Prince Charles Mountains, which poke out of the ice hundreds of kilometres away. Zircons are often called 'time capsules' because they contain minuscule amounts of uranium in their crystal structure, which decays at a known rate and allows scientists to determine their age with great precision. These zircon grains preserve a record of the mountain-building timeline: the Gamburtsev Mountains began to rise around 650 million years ago, reached Himalayan heights by 580 million years ago, and experienced deep crustal melting and flow that ended around 500 million years ago. Most mountain ranges formed by continental collisions are eventually worn down by erosion or reshaped by later tectonic events. Because they've been preserved by a deep layer of ice, the Gamburtsev Subglacial Mountains are one of the best-preserved ancient mountain belts on Earth. While it's currently very challenging and expensive to drill through the thick ice to sample the mountains directly, our model offers new predictions to guide future exploration. For instance, recent fieldwork near the Denman Glacier on East Antarctica's coast uncovered rocks that may be related to these ancient mountains. Further analysis of these rock samples will help reconstruct the hidden architecture of East Antarctica. Antarctica remains a continent full of geological surprises, and the secrets buried beneath its ice are only beginning to be revealed. Jacqueline Halpin is an Associate Professor of Geology at the University of Tasmania. Nathan R. Daczko is a Professor of Earth Science at Macquarie University.
The Independent
28-05-2025
- General
- The Independent
Breakthrough after mysterious mountain range found buried beneath Antarctica's ice
Have you ever imagined what Antarctica looks like beneath its thick blanket of ice? Hidden below are rugged mountains, valleys, hills and plains. Some peaks, like the towering Transantarctic Mountains, rise above the ice. But others, like the mysterious and ancient Gamburtsev Subglacial Mountains in the middle of East Antarctica, are completely buried. The Gamburtsev Mountains are similar in scale and shape to the European Alps. But we can't see them because the high alpine peaks and deep glacial valleys are entombed beneath kilometres of ice. How did they come to be? Typically, a mountain range will rise in places where two tectonic plates clash with each other. But East Antarctica has been tectonically stable for millions of years. Our new study, published in Earth and Planetary Science Letters, reveals how this hidden mountain chain emerged more than 500 million years ago when the supercontinent Gondwana formed from colliding tectonic plates. Our findings offer fresh insight into how mountains and continents evolve over geological time. They also help explain why Antarctica's interior has remained remarkably stable for hundreds of millions of years. A buried secret The Gamburtsev Mountains are buried beneath the highest point of the East Antarctic ice sheet. They were first discovered by a Soviet expedition using seismic techniques in 1958. Because the mountain range is completely covered in ice, it's one of the least understood tectonic features on Earth. For scientists, it's deeply puzzling. How could such a massive mountain range form and still be preserved in the heart of an ancient, stable continent? Most major mountain chains mark the sites of tectonic collisions. For example, the Himalayas are still rising today as the Indian and Eurasian plates continue to converge, a process that began about 50 million years ago. Plate tectonic models suggest the crust now forming East Antarctica came from at least two large continents more than 700 million years ago. These continents used to be separated by a vast ocean basin. The collision of these landmasses was key to the birth of Gondwana, a supercontinent that included what is now Africa, South America, Australia, India and Antarctica. Our new study supports the idea that the Gamburtsev Mountains first formed during this ancient collision. The colossal clash of continents triggered the flow of hot, partly molten rock deep beneath the mountains. As the crust thickened and heated during mountain building, it eventually became unstable and began to collapse under its own weight. Deep beneath the surface, hot rocks began to flow sideways, like toothpaste squeezed from a tube, in a process known as gravitational spreading. This caused the mountains to partially collapse, while still preserving a thick crustal 'root', which extends into Earth's mantle beneath. Crystal time capsules To piece together the timing of this dramatic rise and fall, we analysed tiny zircon grains found in sandstones deposited by rivers flowing from the ancient mountains more than 250 million years ago. These sandstones were recovered from the Prince Charles Mountains, which poke out of the ice hundreds of kilometres away. Zircons are often called 'time capsules' because they contain minuscule amounts of uranium in their crystal structure, which decays at a known rate and allows scientists to determine their age with great precision. These zircon grains preserve a record of the mountain-building timeline: the Gamburtsev Mountains began to rise around 650 million years ago, reached Himalayan heights by 580 million years ago, and experienced deep crustal melting and flow that ended around 500 million years ago. Most mountain ranges formed by continental collisions are eventually worn down by erosion or reshaped by later tectonic events. Because they've been preserved by a deep layer of ice, the Gamburtsev Subglacial Mountains are one of the best-preserved ancient mountain belts on Earth. While it's currently very challenging and expensive to drill through the thick ice to sample the mountains directly, our model offers new predictions to guide future exploration. For instance, recent fieldwork near the Denman Glacier on East Antarctica's coast uncovered rocks that may be related to these ancient mountains. Further analysis of these rock samples will help reconstruct the hidden architecture of East Antarctica. Antarctica remains a continent full of geological surprises, and the secrets buried beneath its ice are only beginning to be revealed. Jacqueline Halpin is an Associate Professor of Geology at the University of Tasmania. Nathan R. Daczko is a Professor of Earth Science at Macquarie University.
Daily Mail
19-05-2025
- General
- Daily Mail
Scientists are GOBSMACKED by never-before-seen footage of the Earth rupturing during an earthquake
Terrifying footage has emerged from March's Myanmar earthquake showing the ground literally sliding either side of two tectonic plates. The astonishing video clip, originally uploaded to Facebook, was captured by a surveillance camera just south of Mandalay, Myanmar's second-largest city. Initially, the clip – captured at 12:46pm local time on March 28 – looks like unremarkable security footage from a private property. But about 10 seconds in, the point-of-view begins to shake up and down, plants flap wildly and the gate starts sliding back and forth. Then, at about 14 seconds, the entire driveway starts to move forward relative to the ground beyond, like some kind of horrible fairground ride. Wendy Bohon, an earthquake geologist and science communicator in California, said her 'jaw hit the floor' when she saw the footage from along the fault line. 'We have computer models of it, we have laboratory models of it, but all of those are far less complex than the actual natural system,' she told CBS News. 'So to see it actually happening was mind-blowing.' An account called 2025 Sagaing Earthquake Archive found the video on Facebook and uploaded it to their YouTube page John Vidale, a seismologist at the University of Southern California Dornsife, said he knows of no other video showing a so-called 'ground rupture'. 'It's really kind of unsettling,' Professor Vidale told Live Science. The footage was captured by a security camera at GP Energy Myanmar's Tha Pyay Wa solar energy facility, just south of Mandalay. An account called 2025 Sagaing Earthquake Archive found the video on Facebook and uploaded it to their YouTube page. Although easily missed, the 'surface rupture' event is best viewed by keeping a close eye beyond the gate to the right of the picture. Dividing the driveway and the road beyond is the fault line – the boundary where two tectonic plates meet. When the 7.7-magnitude quake hit, the ground moved as much as 20 feet (6 metres), according to 2025 Sagaing Earthquake Archive. This is the first and currently only known instance of a fault line motion being captured on camera, the page says. What happened during the Myanmar earthquake? Myanmar sits on the boundary between the Indian and Sunda tectonic plates. Right in the heart of the country, these plates move past each other in a zone called the Sagaing Fault. Researchers have warned that part of the Sagaing Fault had been 'stuck', building up a huge reserve of energy. On March 28, that energy was released in a massive earthquake near Myanmar's population centres. The earthquake was also exceptionally shallow, meaning more energy was transferred into buildings at the surface. The video was posted to YouTube on May 11, where it received 12,000 likes and more than 1,000 comments from astonished users. One person said: 'This video is going to be a staple in geology classrooms, while another called it 'truly a groundbreaking video'. A third said: '[It's] terrifying to see the entire landscape shift, very visceral expression of the energy involved', while a fourth said: 'If you're watching this for the first time and only notice the driveway, rewatch it several times looking at different areas.' Another posted: 'There's so many amazing tiny details in this video, that 30 watches in, I'm still finding new things.' Earthquakes occur when two tectonic plates that are sliding in opposite directions stick and then slip suddenly. Myanmar sits directly on top of the Sagaing Fault – a highly active earthquake zone stretching 745 miles (1,200 km) through the heart of the country. In this region, the Indian and Sunda tectonic plates slide past each other at a speed of 1.9-inch (49mm) per year. When those plates catch and stick, they build up a vast reserve of energy which is then released in a violent 'slip-strike' earthquake, as has happened on March 28. The earthquake originated from a fault that runs the length of the country between the Indian and Sunda tectonic plates. It originated from a region called the Sagaing Fault, near Mandalay In January, geologists from the Chinese Academy of Sciences found that the middle section of the Sagaing fault had been highly 'locked' – meaning the plates had been stuck for an abnormally long time. This indicated that more energy was building up than normal and the researchers warned that the Sagaing fault would be 'prone to generating large earthquakes in the future'. The March 28 earthquake killed more than 5,300 people in Myanmar, as well as more than 100 in neighbouring Thailand and one person in Vietnam. It was the most powerful earthquake to strike Myanmar since 1912 and the second deadliest in Myanmar's modern history. 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.
