Latest news with #SeismologicalResearchLetters
The Hindu
22-07-2025
- Science
- The Hindu
India's water, energy demand spotlight risk of human-induced quakes
Earthquakes are usually natural — but not always. Sometimes some natural factors can combine with human activities to lead to earthquakes as well. Quakes induced by human activities are called human-induced earthquakes. According to one estimate researchers discussed in Seismological Research Letters in 2017, more than 700 human-induced earthquakes have been recorded around the world in the last 150 years, and they are becoming more common. Human activities like mining, extracting groundwater, impounding water behind a dam, injecting fluids into the ground, constructing tall buildings, and engineering coastal structures, among others, have been shown to induce seismic activity. This is because, according to experts, loading and unloading the crust in a repeated manner can cause strain to accumulate between tectonic plates, which would in turn modulate seismic activity. In India, seismologists have also been studying how the amount of water above and below the ground can affect the geological processes. A 2021 study in Scientific Reports reported that shallow earthquakes recorded in the National Capital Region could be linked to excessive groundwater extraction in the region for farming and human consumption. 'It was seen that between 2003 and 2012, when the water table had depleted significantly, there was an increase in seismic activity. The seismic activity reduced after 2014 when the water table stabilised,' Bhaskar Kundu, associate professor at NIT Rourkela and one of the authors of the study, told The Hindu. Managing extraction When groundwater is pumped out, the mass of water maintaining the pressure under the earth is removed, creating jolts on the surface. 'The situation is not of major concern because these earthquakes in the Delhi-NCR region are usually minor, with the maximum going up to 4.5 magnitude,' C.P. Rajendran, geoscientist and author of The Rumbling Earth: The Story of Indian Earthquakes, said. 'It can go up to 5.5, which for a densely populated city like Delhi could have risks.' This is because Delhi lies on several faultlines and is in the Zone 4 seismic risk category, meaning it's a quake-prone region. The risk for earthquakes induced by groundwater extraction is spread across the Gangetic plains, where the water table has been dropping in leaps, Dr. Rajendran said. This is mostly because crops sown in the region still need large quantities of water and very little of that thirst is quenched by rainfall. He added that there is a need to manage the rate of groundwater extraction and its recharge in a scientific manner and while considering the rate of seismic activity in the region. In the past, human-induced earthquakes have devastated lives and property, caused foremost by large dams that change the water load on the surface. On December 11, 1967, for example, an earthquake of 6.3 magnitude wrought significant damage in Koynanagar, a village in Maharashtra. More than 180 people were killed and thousands of houses were destroyed. Several studies that followed blamed the disaster on water overloading in the Koyna hydroelectric dam nearby. Similarly, research has recorded an increase in seismic activity around the Mullaperiyar dam in Idukki, Kerala, which like Delhi also lies in an earthquake-prone zone. Energy and quakes 'The U.S., which has recorded reservoir-induced earthquakes, has implemented regulations on how quickly a dam should be filled and emptied. Such regulations should also be enforced in India to prevent earthquakes,' Vineet K. Gahalaut, Chief Scientist at the National Geophysical Research Institute, told The Hindu. He also said seismic activities in a region should be properly evaluated before a dam is built there. 'Huge dams in seismically active areas like the Himalayas are not recommended because the water load and percolation could change the local stress regime,' Dr. Rajendran said. India's growing energy demand also increases the risk of this type of disaster. 'The methods used to extract energy to meet our needs have significant risks on our earth, be it oil or hydropower,' Dr. Gahalaut said. Fracking — where liquids are injected into the ground to push rocks apart and allow oil and natural gas — has also been shown to induce earthquakes, Dr. Gahalaut added. India currently has 56 fracking sites across six States. In Palghar district in Maharashtra, which has been experiencing a sequence of quakes since 2018, experts have said plate deformation is occurring in an isolated manner. Initial findings by seismologists indicated that the cause could be fluid migration due to rainfall. 'Strong seismic networks using instruments need to be established across India in regions like these, which are experiencing isolated plate deformation, to monitor and track seismic activity more accurately,' Dr. Kundu said. Impact of climate change Scientists have said that climate change can indirectly affect the occurrence of earthquakes and render them more frequent over time. The melting of glaciers due to global warming has been found to trigger earthquakes around Antarctica and Greenland. Changes in rainfall patterns due to climate change have also been known to modulate the water loading process on the surface. For example, sudden heavy rainfall could alter the stress accumulated between tectonic plates and induce seismic activity. The area around the Sahyadri range of the Western Ghats has been recording tremors due to heavy rainfall for this reason. 'The height of the mountains should have been reduced considering the rate of rainfall. However, the mountains have maintained their height due to seismic activity,' Dr. Gahalaut said. Changing rainfall patterns can also change the soil chemistry, Dr. Rajendran said, affecting cropping patterns and compelling farmers to turn to groundwater for irrigation, which can also induce seismic activity. Similarly, longer droughts can also reactivate seismic faults. Such a drought-induced earthquake was recorded in California in 2014. 'The risk of earthquakes is not present at all locations where there is groundwater depletion or huge dams, They have only been recorded in areas that are present on faultlines or are facing plate deformation processes,' according to Dr. Kundu. At present, the rate at which strain has been accumulating along plates and the fraction of this stress that is due to human activities is not possible to ascertain, he added. Experts have thus warned against concluding that such activities are solely to blame for tremors or earthquakes. Research thus far has only shown that these activities could postpone or accelerate tectonic processes causing these movements.
New York Post
30-04-2025
- Science
- New York Post
Major chunk of Pacific coast from California to Canada will sink into the sea if mega-earthquake hits this spot, doomsday study warns
This should have West Coasters shaking in their shoes. Hundreds of miles of coastline in the Pacific Northwest could go straight into the drink if another major earthquake strikes the region, an alarming new study warned. A 600-mile-long earthquake hotspot off the Pacific Coast could be due for another monster rumble — and if one happens, shorelines from northern California to Vancouver, Canada, could suddenly sink 6 feet or more. Towns and cities for hundreds of miles would find themselves in a brand new floodplain, at risk of catastrophic floods and tsunamis at any moment, according to the study published Monday in the journal Proceedings of the National Academy of Sciences. The aforementioned earthquake minefield is called the Cascadia Subduction Zone, an undersea fault line roughly 100 miles off the coast of North America. 6 A beach in Samoa, California, which could be underwater if an earthquake hits. San Francisco Chronicle via Getty Images 6 Damage from a 1964 quake in Anchorage, Alaska. U.S. Geological Survey 6 A map of earthquake hotspots around the Pacific Ocean showing the Cascadia Subduction Zone. FEMA A big quake there could send massive tsunamis hurtling toward the shore and change the landscape forever. It could double the 'flooding exposure of residents, structures and roads,' the study warned. Bridges, power lines and other infrastructure would need to be totally rebuilt or else risk instant destruction in a major storm. The land at risk of flooding would increase by 116 square miles (the equivalent of five Manhattans), the number of people living in floodplains would increase from around 8,000 to 22,000 — and the number of at-risk structures would go from around 13,000 to 36,000, according to the study. Those grim numbers are more than a hypothetical guess: The study's authors looked at data from another monster earthquake that wiped out a section of Canadian coastline in 1700. 6 An off-road vehicle drives the sandy trails of the Samoa Dunes Recreation Area in Samoa, California. 6 Dust rising from the side of a cliff after an earthquake in Coleville, California, on July 8, 2021 via REUTERS 6 Graphics from the study published in 'Proceedings of the National Academy of Sciences' show the possible effects of a major Cascadia quake. PNAS Oral histories by the Huu-ay-aht First Nation, in present-day Vancouver Island, tell of shaking that was so intense they thought two cosmic beings — a thunderbird and a whale — must be fighting it out. Whole forests and villages plunged into the sea, and only one in 600 people living in the area are said to have survived, according to a paper published in Seismological Research Letters. Modern science has backed up that terrifying tale: Researchers discovered 'ghost forests' and fields of native grasses that seem to have been submerged in moments — a kind of geological snapshot of what could happen if the proverbial thunderbird and whale get into another scrap. Earthquakes are impossible to truly predict, but in the next 50 years, scientists have put the odds of a major quake at 7-12% in the Cascadia Zone, and 37-42% for just the southern section, which includes northern California and Oregon. By the year 2060, those odds will have roughly doubled, according to the United States Geological Survey. So if you buy a beach house in the Pacific Northwest, you might also want to get a canoe.
The Independent
17-02-2025
- Science
- The Independent
Scientists finally crack mystery of eerie ‘ghost lantern' orbs linked to strange whispers and slamming doors
Stories of strange 'ghostly' light orbs spotted hovering over railroad tracks around Summerville, South Carolina, and linked to eerie sounds in the area could be due to a seismic phenomenon, a new study says. The lore of the 'Summerville Light' holds that a strange light rarely seen in a remote part of the town is a lantern carried by the ghost of a woman who once waited hours for her husband to return. Sightings of the strange light began to be spun into ghost stories circulated in the 1950s to 1960s, including instances of the orbs slamming doors and making eerie sounds. Now, a new study, published in the journal Seismological Research Letters, suggests at least some of these strange light sightings could be attributed to natural phenomena from earthquakes too small to be felt. This phenomenon, known as earthquake lights, has been observed around the world in the form of glowing spheres, sparks, pillars and other shapes. However, until now, there has been no accepted theory for a possible mechanism behind their appearance. Some theories suggest the light orbs sighted during such quakes could be from the ignition of released underground gases like methane, or radon, or due to an electric discharge from fault movements. In the latest study, seismologist Susan E Hough from the US Geological Survey suggests Summerville's 'ghost' lore could be resulting from the area's unusual mix of shallow faults and railroad tracks in the eastern US. Dr Hough assessed historical accounts of the strange light orbs found in newspapers and books from local bookstores, and compared them with data on earthquakes in the region. The Summerville Light sightings began to be reported in the 1950s and 1960s. And only a few kilometres away there were three magnitude 3.5 to 4.4 earthquakes recorded in the area in 1959 and 1960. Summerville's strange light phenomenon might be shallow earthquakes in the area that could have released a water-soluble gas like radon or methane, which then got ignited by a spark of static electricity or rock movement, the seismologist says. Steel rails of an abandoned railway line and nearby scrap heaps could have also generated an igniting spark, the study said. 'From working in Charleston I know that when old tracks were replaced or repaired, the old tracks weren't always hauled away. You find piles of old metal along the tracks,' Dr Hough said. She suspects gases trapped in water droplets may also explain why the ghost lights in some of these tales seem to occur on dark and misty nights. The seismologists said more studies are needed to confirm if this proposed mechanism can account for earthquake lights. However, she said the theory can be tested easily by using gas detectors to look for escaping gases, or by conducting experiments to look for shallow faults. 'Maybe here we have an example of the recipe for the environments that might generate earthquake lights. And maybe the friendly ghosts are illuminating fault zones in the east,' Dr Hough said.
Yahoo
11-02-2025
- Science
- Yahoo
Experts Think This Haunting Ghost Story Could Be the Result of a Strange Geologic Phenomenon
A railroad track in South Carolina is reportedly haunted by the 'Summerville Ghost'—a ghastly apparition that appears as balls of light. A new study from a seismologist from the U.S. Geological Survey may have solved the mystery. The light is likely caused by a gaseous emission from the Earth itself, possibly as a result of earthquakes. Nearly every town in America has its local legends—the scary stories told at sleepovers or around campfires that someone's friend or cousin always swears they totally saw for real one time. In the town of Summerville, South Carolina, they have the tale of the 'Summerville Ghost.' The story involves a man who either worked for the railroad or simply walked along the tracks every day, depending on which version of the story you hear. (It's been told since the 1950s, so some details vary over time.) One day, that man was struck by a train coming down the tracks that ran between Charleston and Summerville, and in some versions of the story, was even decapitated. But the Summerville Ghost isn't the spirit of the headless man who died on the tracks. Instead, it's supposedly the man's wife. As the blog South Carolina Haunted Houses summarizes: 'In life, the woman would meet her husband every night and the two of them walked back to their house by lamp light{...} Unable to process his death, she continued her ritual of waiting at the train tracks. It is said that her ghost emits a green light that hovers above the road. Some witnesses claimed the light followed them, while others admitted to an overwhelming feeling of sorrow and despair.' Believable or not, there are thousands, maybe millions of these stories across the country and around the world. But what sets Summerville apart is that, according to seismologist Susan Hough, there might be some truth to this one. As reported by IFLScience, Hough—who works at the US Geological Survey (USGS)—has developed a theory to explain not just the lights that define the sightings of the Summerville Ghost, but also the other supposed signs of hauntings that have been reported in the area 'such as cars shaking, doors slamming, and whispered voices being heard without a source.' As you might have guessed, given that Hough is a seismologist for the USGS, the study she and her team recently published in Seismological Research Letters chalks the haunting up to a geological phenomenon—specifically, tremors and earthquakes. Hough attributes the cars shaking to 'earthquakes with a shallow source,' while the whispered voices were likely 'high-frequency shaking noises resulting from tremors,' because 'sound waves at frequencies of 20–200 Hz are within the audible range.' But what about the ghostly lights? That, Hough suggests, could have a few causes. One possibility is a gaseous release from within the earth: 'The gas release hypothesis involves two possible mechanisms,' Hough explained to IFLScience. 'As an inert gas, radon will not ignite, but could potentially be associated with a glow discharge phenomenon, whereby electrons move to an excited state and then fall back to their ground orbital shell. This usually happens at low temperatures, close to the freezing point. [The study] Enomoto (2024) presents other ideas, involving gamma rays in the atmosphere, and radon or radon/methane gas release.' Of course, there's also the possibility that it is an ignited gas, lit by sparks emitted from the train on the tracks. 'But the association could have a different explanation,' Hough notes, '…for example the tendency of railroads to follow corridors that were carved out by faults.' Hough's study was motivated by more than just a desire to be the X-Files' Dana Scully of the geological world, of course: 'The study felt too frivolous for words when I started, but could actually help address a difficult and important problem: which of the many preexisting faults in the east (and elsewhere) are active? Are there more potential seismic zones than the small handful that have produced large earthquakes during the short historic record?' 'My hope,' she concludes, 'is that ghost stories might provide a useful target for investigations, both to understand earthquake lights, and to identify shallow active faults in eastern North America.' 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?
