Latest news with #Geophysical
Yahoo
4 days ago
- 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.
Yahoo
31-03-2025
- Science
- Yahoo
In a Warming World, Why Is the Southern Ocean Getting Cooler?
Climate models predict that as the planet warms, so will the Southern Ocean. But for decades, the waters around Antarctica have grown mysteriously cooler. A new study shows why. With warming, the region is seeing more rainfall and more ice melt, which are introducing more freshwater into the Southern Ocean. Because freshwater is not as dense as saltwater, it stays on the surface of the ocean instead of sinking down below. Freshwater acts like a lid, keeping warmer waters from rising up, scientists say, and the effect is much greater than previously appreciated. Until now, models have failed to fully account for the influence of rain and, in particular, melting. Study coauthor Earle Wilson, of Stanford University, said the impact of meltwater is 'completely missing from most climate models.' Missing freshwater, he and colleagues found, accounts for 60 percent of the mismatch between predicted and actual temperatures. The findings were published in Geophysical Research Letters. 'There's been some debate over whether that meltwater is enough over the historical period to really matter,' said lead study author Zachary Kaufman, also of Stanford. 'We show that it does.' As 'Doomsday' Glacier Melts, Can an Artificial Barrier Save It?
