Latest news with #Geophysical
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?
