Latest news with #FrontiersinEarthScience
Yahoo
11-06-2025
- Science
- Yahoo
Scientists find Aleutian Range volcano offers clues to ‘stealthy' eruptions
Mount Veniaminof is pictured on July 8, 2024. A newly published study of the mountain increases knowledge of what are known as stealthy volcanoes, like Veniaminof. (Photo by Tara Shreve/Alaska Volcano Observatory/University of Alaska Fairbanks Geophysical Institute) An ice-clad behemoth among Alaska's Aleutian Range mountains is sharing secrets about what makes some volcanoes tick — namely, ones that show little sign of erupting before they blow. In a study published Tuesday in the journal Frontiers in Earth Science, scientists said they have discovered why Mount Veniaminof is so stealthy — and that information may help improve volcano forecasting and perhaps save lives. Named after an 18th century Russian Orthodox priest, Veniaminof is what scientists call a 'stealthy volcano,' one that offers practically zero warning that an eruption is imminent. These volcanoes generally do not exhibit the typical precursors to eruptions, which may include rumbling, earthquakes, gas and steam plumes, and swollen or hot ground surfaces. Stealthy volcanoes can be especially hazardous when located close to population centers. Merapi in Indonesia, Galeras in Colombia, Stromboli in Italy and Popocatépetl and Colima in Mexico are examples, according to the paper. Unlike its more urban counterparts, Veniaminof sits in the remote Alaska Peninsula, some 480 miles southwest of Anchorage. The nearest village, Perryville, lies about 20 miles to the south. Perryville's population totaled 81 people at last count. Veniaminof is one of Alaska's most active volcanoes, with 13 recorded eruptions since 1993, according to the study. Unlike Mount Redoubt, which triggered a near-disaster in 1989 when a jet bound for Anchorage lost engine power after flying into an ash cloud before recovering, or Mount Spurr, which coated Anchorage in ash and prompted airport closures during its 1992 eruption, Veniaminof's seismic activity has caused relatively little trouble for Alaska residents. But its eruptions seem to come out of the blue. Of Veniaminof's 13 eruptions in the past three decades, only two produced warning signs, and a 2018 eruption went undetected until three days after it started. The paper's lead author, Yuyu Li, a volcanology doctoral student at the University of Illinois Urbana-Champaign, found Veniaminof's behavior fascinating but disturbing. Given that the volcano can send ash nearly 10 miles into the atmosphere without warning, with the potential for disrupting air travel or posing other hazards, Li wanted to know more. She and her team analyzed open-source monitoring data over three summer seasons immediately before the 2018 eruption. They created a model to understand what factors influence the likelihood of Veniaminof erupting. They considered several parameters, including magma flow rates, magma volumes and temperatures, and reservoir depths and shapes. In a phone interview on Tuesday, Li said she and her colleagues found that a high flow of magma, or molten rock, into what's known as a chamber increases the chances of an eruption. The volcano may not erupt. But if magma quickly fills the chamber and an eruption does occur, the ground will likely bulge or otherwise change shape, a process called deformation. That's something scientists would be able to detect. They also found rapid movement of magma into a small chamber is likely to produce an eruption capable of being detected, not one without warning. Stealthy eruptions occur more often when a low flow of magna enters a relatively small chamber, according to the research. The study's results suggest that Veniaminof has a small magma chamber and a low flow of magma. A chamber's size and shape factor heavily into the equation. Minimal earthquakes occur when magma enters larger, flatter chambers, according to the research. Elongated chambers seem to produce less ground disturbance or deformation. If the rock is warm, it's less likely to crumble in ways that produce earthquakes. Stealthy eruptions only occur when the precise conditions exist, involving the right magma flow and the right chamber size, depth and shape. One of the paper's big takeaways is that volcanoes with small, warm reservoirs and slow magma flows are among those that ought to be most closely watched. The biggest hazard from any eruption in Alaska is ashfall and disruption to aviation. Anything we can do to help predict that is important. – Dave Schneider, acting scientist-in-charge, Alaska Volcano Observatory Using the model created by Li and her colleagues and adding more instrumentation and real-time monitoring to stealthy volcanoes could help keep the public safer, Li said. It's a recipe for opening the door to improved volcano forecasting. Dave Schneider, acting scientist-in-charge at the Alaska Volcano Observatory, didn't have a chance to read the full study on Tuesday. But from what he gleaned from the news release, he said AVO scientists will evaluate it and determine if any of the findings and recommendations should be implemented. 'The biggest hazard from any eruption in Alaska is ashfall and disruption to aviation,' said Schneider. 'Anything we can do to help predict that is important, given the constraints we have in terms of being able to get things in the ground and be able to interpret the data.' Other stealthy volcanoes in Alaska include Cleveland, Shishaldin and Pavlov. The National Volcano Early Warning System lists them, as well as Veniaminof and others, as high priority in terms of their threat level. Highest on the threat list are Akutan, Augustine, Makushin, Redoubt and Spurr. Logistics and finances don't always allow for high-tech, costly instruments to be placed in as many spots as volcanologists would like or to the extent they would prefer to see. 'Resources are finite,' Schneider said. Eruptions from stealthy volcanoes in Alaska also tend to be less explosive and life- and property-threatening than those from volcanoes offering ample warning signs, he said. Right now, Spurr is by far more of an issue than Veniaminof for volcanologists. The volcano, located about 75 miles west of Anchorage, is currently in 'code yellow' status. That means low-level unrest is occurring with small earthquakes continuing beneath the surface and a weak steam plume arising from the top. If magma were to move closer to the surface and other eruption indications were present, like ground deformation or increased hot gases and vapor plumes, the threat level would rise and scientists would advise the public that an eruption is very likely. In March, scientists predicted that Spurr would erupt within weeks or months but the threat has since lessened. SUPPORT: YOU MAKE OUR WORK POSSIBLE
Yahoo
31-01-2025
- Science
- Yahoo
Africa is going through a massive breakup thanks to an impending continental separation
When you buy through links on our articles, Future and its syndication partners may earn a commission. Africa is dividing in two, and a new landmass and ocean may form sooner than expected. The change could alter the climate and ecosystem of the region, as well as the way humans live. In the geologic history of Earth, shifting plate tectonics are commonplace. Africa's impending rift is but another chapter in that story. The Earth's continents are far from constant. Plate tectonics have caused the landmasses to shift over time, and another shift is occurring in the 21st century. Scientists have known for the past two decades that Africa has been splitting. In 2005, Ethiopia experienced earthquakes that caused the appearance of a 35-mile-long fissure in the desert called the East African Rift. "It marked the start of a long process in which the African plate is splitting into two tectonic plates: the Somali plate and the Nubian plate," said Unilad. Then, in 2018, another crack appeared in Kenya along the rift. The cracks are "associated with the East African Rift System (EARS)," which stretches "downward for thousands of kilometers through several countries in Africa, including Ethiopia, Kenya, the Democratic Republic of the Congo, Uganda, Rwanda, Burundi, Zambia, Tanzania, Malawi and Mozambique," said IFL Science. The rift has been widening over time, and along the system there have been varying levels of seismic activity, according to a study published in the journal Frontiers in Earth Science. But "in the human life scale, you won't be seeing many changes," Ken Macdonald, a professor at the University of California, Santa Barbara, said to Daily Mail. "You'll be feeling earthquakes, you'll be seeing volcanoes erupt, but you won't see the ocean intrude in our lifetimes." Even with the long timelines, scientists suggest that the rift is happening quicker than previously thought. Original estimates put a complete split at tens of millions of years from now. "With the continent dividing at a rate of half an inch per year, those estimations have sped up," said Unilad. MacDonald puts the timeline at between one million and five million years. The split will change the world's continental makeup. "Somalia, Kenya, Tanzania and some parts of Ethiopia would form a new continent separated by the world's sixth ocean," said Metro. A change this drastic could have major implications for the region's biodiversity and ecosystem. Landlocked nations like Uganda and Zambia would gain coastlines which could influence weather patterns and climate. "This transformation could affect biodiversity, water resources and agricultural practices, posing both challenges and opportunities for the inhabitants of East Africa," said HowStuffWorks. In addition "the gradual separation might influence the continent's geopolitical landscape," and "create new opportunities for trade and communication." A new continent is small potatoes in the context of Earth's geological history. All the continents were once a giant landmass known as Pangea, which then split off into the continents we know today. Only recently, scientists mapped the hidden continent of Zealandia located in the Southern Ocean. Africa's split "will be just another move in this giant geological playbook," said IFL Science. "Whether we as a species will survive for long enough to witness it? Well, that's a different story."
