The eruption of Hung volcano provides an explosion of data
Giant January 15, 2022 eruption with Underwater volcano Hung in the South Pacific devastated the island nation of Tonga and created a diversity with atmospheric wave types, including sounds audible for 6,200 miles (10,000 km) in Alaska. It also created an atmospheric impulse that caused an unusual tsunami-like excitement that arrived on the shores of the Pacific Ocean earlier than the actual tsunami.
This is among the many observations reported by a team of 76 scientists from 17 countries who studied atmospheric eruption waves, the largest known from the volcano since 1883 The eruption of Krakatoa. The work of the team, compiled in an unusually short period of time due to significant scientific interest in the eruption, was published on May 12, 2022 in the journal Science.
David Phee, director of the Wilson Alaska Technical Center at the Fairbanks Institute of Geophysics in Alaska, is the lead author of the research work and one of four center scientists involved in the study.
The eruption of the Hung near the island of Tonga gave an unprecedented view of the behavior of some atmospheric waves. A dense network of barometers, infrasound sensors and seismometers in Alaska, operated by the Wilson Technical Center of Alaska Geophysical Institute, the Alaska Volcanic Observatory and the Alaska Center for Earthquakes, have contributed to the data.
“We hope we can better monitor volcanic eruptions and tsunamis by understanding the atmospheric waves of this eruption,” said Phi, who is also a coordinating scientist. in the part of the Alaska Volcanic Observatory owned by the Geophysical Institute.
“Atmospheric waves have been recorded across a wide range of frequencies, and by studying this excellent data set, we will better understand the generation, propagation and recording of acoustic and atmospheric waves,” he said. “This is important for monitoring nuclear explosions, volcanoes, earthquakes and many other phenomena.”
Researchers have found particularly interesting the behavior of the Lamb wave during the eruption, a type named after its discoverer in 1917, the English mathematician Horace Lamb.
The largest atmospheric explosions, such as volcanic eruptions and nuclear tests, create Lamb waves. They can last from minutes to several hours.
A Lamb wave is a type of controlled wave that travels parallel along the surface of a material and also travels upward. During the Hung eruption, a wave traveled along the Earth’s surface and flew around the planet four times in one direction and three times in the opposite – the same thing that was observed during the Krakatovo eruption in 1883.
“Lamb waves are rare. We have very few quality observations of them, ”Phee said. “By understanding the Lamb wave, we can better understand the source and the eruption. This is due to the tsunami and volcanic plume, and probably due to higher infrasonic and acoustic waves from the eruption.
The Lamb wave consisted of at least two pulses near the Hung, with the first having a 7-10-minute increase in pressure followed by a second and greater compression and a subsequent long decrease in pressure.
The wave also reached the Earth’s ionosphere, rising at 700 miles per hour to an altitude of about 280 miles, according to ground stations.
The main difference from the Lamb wave during the Hung explosion compared to the 1883 wave is the amount of data collected due to more than a century of technology and the spread of sensors around the world, the article said.
Scientists have noted other findings about atmospheric waves associated with the eruption, including “excellent” long-range infrasound – sounds too low to be heard by humans. Infrasound arrived after the Lamb wave and in some regions was accompanied by sounds.
The sounds, as noted in the paper, traveled about 6,200 miles to Alaska, where they were heard across the state in the form of repeated sounds about nine hours after the eruption.
“I heard sounds, but at the time I didn’t think it was from a volcanic eruption in the South Pacific,” Phee said.
Reports of Alaska are the most documented reports of audible sound from its source. In part, the document notes, this is due to population growth in the world and progress in relation to society.
“We will study these signals over the years to find out how atmospheric waves were created and how they propagated so well across the Earth,” Phee said.
Reference: “Atmospheric waves and global seismic observations of the Hung eruption in January 2022, Tonga” Robin S. Matoza, David Phi, Jel D. Asink, Alexandra M. Iezi, David N. Green, Kihun Kim, Liam Tony, Thomas Lecock , Siddhartha Krishnamurti, Jean-Marie Lalande, Kivamu Nishida, Kent L. Guy, Matthew M. Haney, Hugo D. Ortiz, Quentin Brisso, Leo Martir, Lucy Roland, Panagiotis Vergados, Alexandra Nippress, Junjong Park, Shahar-Kahad -Shani Alex Witsill, Stephen Arrowsmith, Quarantine Codron, Shinga Watada, Anna B. Perth, Benoit Tesne, Pierre Mialle, Alexis Le Pichon, Julien Vergoz, Patrick Jupp, Philip S. Blom, Roger Waxler, Sylvio DeJonato B. Snyvley Adam T. Ringler, Robert E. Anthony, Arthur D. Jolie, Jeff Kilgour, Gil Averbuch, Maurizio Ripepe, Mi Ichihara, Alejandro Arsinega-Sebalos, Elvira Astafyeva, Lars Serrano, Sandrine Cheng-Yeward , Rodrigo De Negri Carl W. Ebeling, Leslo G. Evers, Louis E. Franco-Marine, Thomas B. Gabrielson, Catherine Hafner, R. Giles Harrison, Attila Kamjati, D Georgio Lacan, John Lyons, Kenneth A. McPherson, Emanuele Marchetti, Kathleen F. McKee, Robert J. Mellors, Gerardo Menda-Perez, T. Dylan Michesel, Edha Munaybari, Meira Abaibari-Merced, Isel Park, Christoph Pilger, Christina Ramos, Mario K. Ruiz, Roberto Sabatini, Hans F. Schweiger, Dariana Tailpid, Kerry , Jeremy Webster and David K. Wilson, May 12, 2022, Science.
DOI: 10.1126 / science.abo7063
Other Geophysical Institute scientists involved in the study include graduate student Liam Tony, acoustic wave analysis, figure creation and animation; Dr. Alex Witsill, acoustic wave analysis and equivalent explosive power analysis; and seismic researcher Kenneth A. McPherson, sensor response and data quality. All are at the Wilson Alaska Technical Center.
The Alaska Volcano Observatory, the National Science Foundation, and the U.S. Defense Threat Reduction Agency funded some of the UAF’s research.
Robin S. Matosa of the University of California, Santa Barbara is the lead author of the article.