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Tag: Seismology

  • Lava from Hawaii volcano lights night sky amid warnings

    Lava from Hawaii volcano lights night sky amid warnings

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    KAILUA-KONA, Hawaii — Waves of orange, glowing lava and ash blasted and billowed from the world’s largest active volcano in its first eruption in 38 years, and officials told people living on Hawaii’s Big Island to be ready in the event of a worst-case scenario.

    The eruption of Mauna Loa wasn’t immediately endangering towns, but the U.S. Geological Survey warned the roughly 200,000 people on the Big Island that an eruption “can be very dynamic, and the location and advance of lava flows can change rapidly.”

    Officials told residents to be ready to evacuate if lava flows start heading toward populated areas. Monday night, hundreds of people lined a road as lava flowed down the side of Mauna Loa and fountained into the air.

    The eruption migrated northeast throughout Monday and spread out over the side of the volcano, with several distinct streams of lava running down the hillside.

    The eruption began late Sunday night following a series of fairly large earthquakes, said Ken Hon, scientist-in-charge at the Hawaiian Volcano Observatory.

    The areas where lava was emerging — the volcano’s summit crater and vents along the volcano’s northeast flank — are both far from homes and communities.

    Officials urged the public to stay away from them, given the dangers posed by lava, which is shooting 100 to 200 feet (30 to 60 meters) into the air out of three separate fissures roughly estimated to be 1 to 2 miles (1.6 to 3.2 kilometers) long.

    Volcanic gases wafting out of the vents, primarily sulfur dioxide, are also harmful.

    Air quality on the Big Island more generally is good right now, but officials are monitoring it carefully, said Dr. Libby Char, the director of the state Department of Health.

    Hon said air quality could deteriorate while the eruption lasts, which scientists expect will be about one or two weeks if the volcano follows historical patterns.

    Lifelong Big Island resident Bobby Camara, who lives in Volcano Village, said everyone across the island should keep track of the eruption. He said he’s seen three Mauna Loa eruptions in his lifetime and stressed the need for vigilance.

    “I think everybody should be a little bit concerned,” he said. “We don’t know where the flow is going, we don’t know how long it’s going to last.”

    Gunner Mench, who owns an art gallery in Kamuela, said he awoke shortly after midnight and saw an alert on his phone about the eruption.

    Mench and his wife, Ellie, ventured out to film the eerie red glow cast over the island, watching as lava spilled down the volcano’s side.

    “You could see it spurting up into the air, over the edge of this depression,” Mench said.

    “Right now it’s just entertainment, but the concern is” it could reach populated areas, he said.

    Seeing Mauna Loa erupt is a new experience for many residents of the Big Island, where the population has more than doubled from 92,000 in 1980.

    More than a third of the island’s residents live either in the city of Kailua-Kona to the west of the volcano, or about 23,000 people, and Hilo to the east, with about 45,000. Officials were most worried about several subdivisions some 30 miles (50 kilometers) to the volcano’s south that are home to about 5,000 people.

    A time-lapse video of the eruption from overnight showed lava lighting up one area, moving across it like waves on the ocean.

    The U.S. Geological Survey said the eruption had migrated to a rift zone on the volcano’s northeast flank. Rift zones are where the mountain rock is cracked and relatively weak — making it easier for magma to emerge.

    Lava could move toward the county seat of Hilo, but that could take about a week, Hon said at a news conference.

    Scientists hope the flow will parallel the 1984 eruption, where the lava was more viscous and slowed down.

    Mauna Loa has another rift zone on its southwest flank. Lava could reach nearby communities in hours or days if the volcano erupts from this area. But Hon said historically Mauna Loa has never erupted from both rift zones simultaneously.

    “So we presume at this point that all of the future activity is going to be on the northeast rift zone of Mauna Loa and not on the southeast rift zone,” he said. “So those residents in that area do not have to worry about lava flows.”

    Hawaii County Civil Defense announced it had opened shelters because it had reports of people evacuating from along the coast on their own initiative.

    The USGS warned residents who could be threatened by the lava flows to review their eruption preparations. Scientists had been on alert because of a recent spike in earthquakes at the summit of the volcano, which last erupted in 1984.

    Portions of the Big Island were under an ashfall advisory issued by the National Weather Service in Honolulu. It said up to a quarter-inch (0.6 centimeters) of ash could accumulate in some areas.

    “Volcanic gas and possibly fine ash and Pele’s hair may be carried downwind,” Gov. David Ige said, referring to glass fibers that form when hot lava erupts from a fissure and rapidly cools in the air. The wind stretches the fibers into long strands that look like hair. “So certainly we would ask those with respiratory sensitivities to take precautions to minimize exposure.”

    Mauna Loa is one of five volcanoes that together make up the Big Island of Hawaii, the southernmost island in the Hawaiian archipelago.

    Mauna Loa, rising 13,679 feet (4,169 meters) above sea level, is the much larger neighbor of Kilauea, which erupted in a residential neighborhood and destroyed 700 homes in 2018. Some of Mauna Loa’s slopes are much steeper than Kilauea’s, so lava can flow much faster when it erupts.

    During a 1950 eruption, the mountain’s lava traveled 15 miles (24 kilometers) to the ocean in under three hours.

    Mauna Loa’s volume is estimated at least 18,000 square miles (75,000 square kilometers), making it the world’s largest volcano when measured from the ocean floor its summit.

    Tourism is Hawaii’s economic engine but Big Island Mayor Mitch Roth predicted few problems for those vacationing during the eruption.

    “It will be spectacular where it is, but the chances of it really interrupting the visitor industry — very, very slim,” he said.

    Tourism officials said no one should have to change Big Island travel plans.

    For some, the eruption might cut down on some travel time, even if there is more volcanic smog caused by higher sulfur-dioxide emissions.

    “But the good thing is you don’t have to drive from Kona over to Hawaii Volcanoes National Park to see an eruption anymore,” Roth said. “You can just look out your window at night and you’ll be able to see Mauna Loa erupting.”

    ———

    Contributing to this report were Associated Press writers Jennifer Sinco Kelleher and Audrey McAvoy in Honolulu; Alina Hartounian in Phoenix; and Mark Thiessen in Anchorage, Alaska.

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  • Remote undersea volcano likely erupting in Pacific Ocean

    Remote undersea volcano likely erupting in Pacific Ocean

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    HONOLULU — A volcano is likely erupting deep beneath the Pacific Ocean in the U.S. Commonwealth of the Northern Mariana Islands, but scientists don’t know for sure because it’s so inaccessible.

    All indications are that the Ahyi Seamount began erupting in mid-October, the U.S. Geological Survey said Monday. The Northern Marianas are about 3,800 miles (6,115 kilometers) west of Honolulu.

    Scientists are looking to see if the activity is shallow earthquakes or if material exploded from the crater, said Matt Haney, a USGS research geophysicist. Scientists are checking satellite data to see if there’s discolored water, which could suggest material is coming out of the volcano, he said.

    “There’s nothing right now that suggests that this eruption will intensify and become a large eruption,” Haney said.

    Still, mariners would want to avoid the immediate area, he said.

    Activity from an undersea volcanic source was picked up last month by hydroacoustic sensors some 1,400 miles away (2250 kilometers) at Wake Island.

    With help from the the Laboratoire de Geophysique in Tahiti and data from seismic stations in Guam and Japan, scientists analyzed the signals to determine the source of the activity was likely Ahyi Seamount, the USGS said in a statement.

    Activity has been declining in recent days, the statement said.

    Ahyi seamount is a large conical submarine volcano. Its highest point is 259 feet (79 meters) below the surface of the ocean. It’s located about 11 miles (18 kilometers) southeast of the island of Farallon de Pajaros, also known as Uracas.

    “There are no local monitoring stations near Ahyi Seamount, which limits our ability to detect and characterize volcanic unrest there,” the agency said. “We will continue to monitor available remote hydrophonic, seismic, and satellite data closely.”

    The seamount is part of the Mariana Volcanic Arc, which is a chain of over 60 active volcanoes stretching over 600 miles west of and parallel to the Mariana Trench, the world’s deepest point.

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  • Two NASA spacecraft detect biggest meteor strikes at Mars

    Two NASA spacecraft detect biggest meteor strikes at Mars

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    CAPE CANAVERAL, Fla. — Two NASA spacecraft at Mars — one on the surface and the other in orbit — have recorded the biggest meteor strikes and impact craters yet.

    The high-speed barrages last year sent seismic waves rippling thousands of miles across Mars, the first ever detected near the surface of another planet, and carved out craters nearly 500 feet (150 meters) across, scientists reported Thursday in the journal Science.

    The larger of the two strikes churned out boulder-size slabs of ice, which may help researchers look for ways future astronauts can tap into Mars’ natural resources.

    The Insight lander measured the seismic shocks, while the Mars Reconnaissance Orbiter provided stunning pictures of the resulting craters.

    Imaging the craters “would have been huge already,” but matching it to the seismic ripples was a bonus, said co-author Liliya Posiolova of Malin Space Science Systems in San Diego. “We were so lucky.”

    Mars’ atmosphere is thin unlike on Earth, where the thick atmosphere prevents most space rocks from reaching the ground, instead breaking and incinerating them.

    A separate study last month linked a recent series of smaller Martian meteoroid impacts with smaller craters closer to InSight, using data from the same lander and orbiter.

    The impact observations come as InSight nears the end of its mission because of dwindling power, its solar panels blanketed by dust storms. InSight landed on the equatorial plains of Mars in 2018 and has since recorded more than 1,300 marsquakes.

    “It’s going to be heartbreaking when we finally lose communication with InSight,” said Bruce Banerdt of NASA’s Jet Propulsion Laboratory, the lander’s chief scientist who took part in the studies. “But the data it has sent us will certainly keep us busy for years to come.”

    Banerdt estimated the lander had between four to eight more weeks before power runs out.

    The incoming space rocks were between 16 feet and 40 feet (5 meters and 12 meters) in diameter, said Posiolova. The impacts registered about magnitude 4.

    The larger of the two struck last December some 2,200 miles (3,500 kilometers) from InSight, creating a crater roughly 70 feet (21 meters) deep. The orbiter’s cameras showed debris hurled up to 25 miles (40 kilometers) from the impact, as well as white patches of ice around the crater, the most frozen water observed at such low latitudes, Posiolova said.

    Posiolova spotted the crater earlier this year after taking extra pictures of the region from orbit. The crater was missing from earlier photos, and after poring through the archives, she pinpointed the impact to late December. She remembered a large seismic event recorded by InSight around that time and with help from that team, matched the fresh hole to what was undoubtedly a meteoroid strike. The blast wave was clearly visible.

    Scientists also learned the lander and orbiter teamed up for an earlier meteoroid strike, more than double the distance of the December one and slightly smaller.

    “Everybody was just shocked and amazed. Another one? Yep,” she recalled.

    The seismic readings from the two impacts indicate a denser Martian crust beyond InSight’s location.

    “We still have a long way to go to understanding the interior structure and dynamics of Mars, which remain largely enigmatic,” said Doyeon Kim of ETH Zurich’s Institute of Geophysics in Switzerland, who was part of the research.

    Outside scientists said future landers from Europe and China will carry even more advanced seismometers. Future missions will “paint a clearer picture” of how Mars evolved, Yingjie Yang and Xiaofei Chen from China’s Southern University of Science and Technology in Shenzhen wrote in an accompanying editorial.

    ———

    The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

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