Latest news with #Geophysical
Metro
2 days ago
- Science
- Metro
Hidden 620 mile crack beneath North America could trigger massive earthquake
A crack stretching more than 620 miles across northwestern Canada could one day cause 'at least' a 7.5 magnitude earthquake. Tintina is a fault line – where two of Earth's puzzle pieces, tectonic plates, meet – which runs from northeastern British Columbia to central Alaska. Experts have never worried too much about it, believing it has been asleep for about 40million years. But researchers have revealed in a new study that an 81-mile-long stretch of the fault line in Yukon has been very much awake for 2.6million years. The study, published in the Geophysical Research Letters, found that the crack has produced multiple strong tremors between a magnitude of three and four, enough to cause minor damage. Worryingly, whether the fault could cause an even larger tremor isn't a question of if; it's when. The most active chunk is grumbling about 12 miles from Dawson City, a town home to 1,500 people, University of Victoria researchers found. Tintina is a right-lateral strike-slip fault, where two chunks of the Earth's crust slide against each other horizontally. By looking at how far the landforms have shifted around, scientists pieced together the fault's recent movements. And by 'recent', we mean geologically recent. One side of the fault slipped about 270 miles during the Eocene period, some 55million years ago. But the team realised that Tintina is more active than first thought by examining fault scarps, steep slopes and cliffs formed by earthquakes. These scarps can easily be tens of miles long, but only a few metres wide and tall, making them tricky to see in forested areas like Canada. The scientists used satellite images and data to identify fault scarps near Dawon City that suggest the last time the fault experienced a major earthquake was at least 12,000 years ago. Two tectonic grinding on one another causes friction and pressure to build up. Once the force of the plates moving exceeds the friction, they suddenly jolt and release seismic waves that shake the ground, causing a quake. With 12,000 years of pressure built up, the study warned that Tintina is overdue for a Big One. Lead author Theron Finley said in a statement: 'We determined that future earthquakes on the Tintina fault could exceed magnitude 7.5.' 'Based on the data, we think that the fault may be at a relatively late stage of a seismic cycle.' A 7.5 magnitude earthquake and the tsunami that followed it killed more than 4,300 people in Indonesia in 2018. While 645 people died after a 7.5 quake shook Noto, a peninsula in northern Japan, last year. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Finley's team added that a quake of this scale would rattle Dawson City and could pose a threat to nearby roads and mines. Dr Jonathan Paul, a senior lecturer from the Department of Earth Sciences at Royal Holloway, University of London, told Metro that Tintina is a 'spectacular fault not to have been detected before'. 'It's like San Andreas, only about six times as long,' he said, referring to the tension-wracked fault line slicing through California. 'It's in a very remote location so, even if there were a huge earthquake, the damage to people's livelihoods and the local economy is likely to be minimal.' More Trending Dr Paul said that it's 'impossible to predict' when an earthquake might happen, and the one that could happen along Tintina is no exception. He added: 'Digging trenches across the fault would also be a prerequisite to understanding whether the fault is likely to move in a single jump, releasing a huge amount of energy all at once (i.e. an earthquake) or whether movement might take the form of a cluster of much smaller ruptures, or even slower creep motion. Dr Ian Stimpson, a senior lecturer in geophysics at Keele University, similarly said that there's no suggestion the quake hitting the remote region is 'imminent'. 'If I were Canadian, I would be more concerned about a magnitude seven-plus earthquake from the Cascadia subduction zone beneath Vancouver, a region with 2.7 million people living there,' he told Metro. Get in touch with our news team by emailing us at webnews@ For more stories like this, check our news page. MORE: At least one woman killed as 6.1 magnitude earthquake rocks Turkey MORE: My week in the world's most welcoming city where immigrants are 'newcomers' MORE: Moment huge black bear is chased out of home by tiny Pomeranian dog
Filipino Times
27-07-2025
- Climate
- Filipino Times
Rains Expected Over Parts of Luzon on July 28 Due to Southwest Monsoon
The southwest monsoon, or habagat, will bring rains to several areas in Luzon on Monday, July 28, according to the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (Pagasa). In a 5 p.m. weather update, Pagasa weather specialist Veronica Torres said that regions such as Cagayan Valley, the Cordillera Administrative Region, Ilocos Region, Central Luzon, and parts of CALABARZON and MIMAROPA — including Laguna, Batangas, Cavite, Rizal — are likely to experience rainfall due to habagat. Fair weather is expected in areas like Quezon Province and the Bicol Region, although localized thunderstorms may still occur. Visayas and Mindanao will also see generally fair conditions, with chances of isolated thunderstorms. No gale warnings have been issued for any of the country's coastal areas. Here are the temperature forecasts for Monday in select locations: Metro Manila: 25°C to 30°C Laoag, Ilocos Norte: 25°C to 30°C Baguio City: 17°C to 21°C Tuguegarao: 26°C to 32°C Legazpi, Albay: 25°C to 32°C Tagaytay: 23°C to 28°C Puerto Princesa & Kalayaan Islands: 25°C to 31°C Cebu & Tacloban: 27°C to 33°C Iloilo: 25°C to 32°C Zamboanga & Cagayan de Oro: 25°C to 34°C Davao: 26°C to 33°C Meanwhile, Pagasa's Obet Badrina noted that Metro Manila is expected to have minimal rain during the morning of President Ferdinand Marcos Jr.'s fourth State of the Nation Address (SONA), but isolated thunderstorms could develop by late afternoon or evening.
Yahoo
17-06-2025
- Science
- Yahoo
Scientists issue warning after making troubling discovery in waters off Antarctica: 'Could be more unstable'
A recent discovery by a team of Australian scientists reveals that an ocean current, which acts as a safeguard by protecting Antarctica from warm water that would otherwise melt the region's ice, is at risk of failing. Relatively little is known about the Antarctic Slope Current (ASC), but scientists do understand its importance in acting as Antarctica's last line of defense from preventing warm water from invading the region. New research that was recently published in Geophysical Research Letters looks at how this current, which acts as a vital barrier, "will respond to changes in wind, heating, and meltwater under climate change." "We found meltwater from Antarctica is speeding up the current, known as the Antarctic Slope Current," the authors of the study wrote in an article for the Conversation, per "And it's set to become even faster by mid-century." "A faster current could be more unstable," added the researchers. "This means eddies of warm water could eat away at Antarctica's ice, posing a major concern for the stability of Earth's climate system." The team of scientists warned that "humanity must act now" to protect this natural buffer, which is helping to keep Antarctica's ice shelves from vanishing. The study's authors point out that in vulnerable low-lying coastal regions, even a minimal sea-level rise of just a few centimeters can double the likelihood of flooding events. Rising sea levels allow saltwater to encroach further inland, contaminating freshwater supplies and impacting crop yields. The Union of Concerned Scientists has linked human activity to rising global temperatures that are melting ice sheets and releasing vast volumes of freshwater into the North Atlantic. This invasion of freshwater is disturbing the delicate balance of ocean circulation patterns and contributing to rising sea levels as the relatively less salty and less dense water takes up more space. A study published in May showed that the Northeastern U.S. experienced up to eight days of flooding annually because of the disruption of the Atlantic Meridional Overturning Circulation. The research concluded that up to 50% of the total flooding events at monitored sites in the Northeast might be tied directly to the weakening circulation. Rising sea levels in Charleston, South Carolina, are making what used to be an occasional nuisance for the coastal city into a more routine disruption for the community, as rising tides bring water into homes and businesses. "Humanity must act fast to preserve the current, by cutting carbon emissions," warned the authors of the study on the changes to the ASC. "When it comes to Antarctica, this action isn't optional—it's the only way to hold the line." Transitioning from dirty energy sources to clean, renewable options is the most effective way to cut carbon pollution that is overheating our planet. Even relatively small changes we can make in our homes can help. Washing clothes in cold water, upgrading to LED bulbs, and unplugging "energy vampires" can have an impact and make a difference. Do you think America does a good job of protecting its natural beauty? Definitely Only in some areas No way I'm not sure Click your choice to see results and speak your mind. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
GMA Network
27-05-2025
- Climate
- GMA Network
PAGASA warns of danger level heat index in 22 areas on May 28, 2025
The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) expects the heat index to reach dangerous levels in 22 areas across the country on Wednesday, May 28, 2025. According to the state weather bureau's advisory on May 27, these areas are forecast to experience heat indices ranging from 42°C to 45°C, significantly increasing the risk of heat-related illnesses such as heat cramps, exhaustion, and even heat stroke with prolonged exposure. Areas with highest projected heat index: 45°C Butuan City, Agusan del Norte 44°C Laoag City, Ilocos Norte Dagupan City, Pangasinan Masbate City, Masbate Basco, Batanes 43°C MMSU, Batac, Ilocos Norte Bacnotan, La Union CBSUA-Pili, Camarines Sur Catarman, Northern Samar Dipolog, Zamboanga del Norte 42°C NAIA, Pasay City (Metro Manila) Sinait, Ilocos Sur NVSU, Bayombong, Nueva Vizcaya ISU, Echague, Isabela Baler, Aurora Iba, Zambales Daet, Camarines Norte Legazpi City, Albay Virac, Catanduanes Juban, Sorsogon Zamboanga City, Zamboanga del Sur Hinatuan, Surigao del Sur The heat index, often referred to as the "apparent temperature," represents how hot conditions feel to the human body by factoring in both air temperature and relative humidity. PAGASA classifies temperatures between 42 degrees Celsius and 51 degrees Celsius as the "danger" level, where heat cramps and exhaustion are likely, and heat stroke is possible with continued exposure. The weather bureau urges the public to limit outdoor activities, remain hydrated, and wear fresh clothes to avoid heat-related illnesses. — VDV, GMA Integrated News
Hindustan Times
26-04-2025
- Science
- Hindustan Times
Spin cycle: Why Earth's rotational speed is changing
Talk about making the world go round. Earth's rotational speed is changing, and we're more than partly responsible. A gigantic dam, our extraction of groundwater, melting ice sheets and rising sea levels are among the human-linked factors altering Earth's spin. The thing all these factors have in common, is water. Where it stands, how it flows and where it settles has always shaped Earth's rotation. During the last Ice Age, which ended about 20,000 years ago, for instance, the weight of the ice was so great that it depressed the surface of the planet. As it melted, large parts of the planet returned to their original form, leading to shifts in the orbit then too. Giant earthquakes have also traditionally altered Earth's rotation, in tiny but still real ways. Anything that redistributes Earth's mass can cause such a change. One of the things now estimated to do this is the world's most powerful dam. China's Three Gorges Dam across the Yangtze River generates more hydroelectric power than certain small countries. Completed in 2006, it is over 7,500 ft long and 600 ft tall. At capacity, it holds back (and draws power from) 10 trillion gallons of water. Because this water has been moved from a lower elevation to a higher one, at a certain distance from the equator, it has likely caused a measurable shift in the Earth's spin. According to research by Benjamin Fong Chao, a geophysicist with the US National Aeronautics and Space Administration (NASA), released in 2005, the dam has likely increased the length of a day by 0.06 microseconds (for context, there are a million microseconds in a second). Incidentally, other dams have been said to cause infinitesimal shifts in spin too; few have been studied as closely as the Three Gorges. Elsewhere, 'contemporary mass loss' and its impact on Earth's rotation are being studied on two primary fronts: the cracking and collapsing of ice sheets at the poles, and the extraction of massive volumes of groundwater over time. Through the 20th century, the Greenland ice sheet (the largest ice mass in the northern hemisphere) has had an estimated 7,500 billion tonnes of ice melt into the ocean. The rate of melting has since sped up. NASA estimates that about 270 billion tonnes are now being lost a year in Greenland, and another 135 billion tonnes are being lost in Antarctica. Meanwhile, humans pumped out more than 2,100 billion tonnes of groundwater between 1993 and 2010 alone, according to a study by Korean geophysicist Ki-Weon Seo, published in Geophysical Research Letters in 2023. Most of it eventually ended up in the sea. This shifting of mass directly affects Earth's rotation too. The direct implications of such shifts are felt in areas that rely on extreme precision, such as satellite orbits, GPS accuracy and the synchronisation of atomic clocks. The impacts of the factors causing the shifts, of course, are a matter of survival.
