Phys.org July 14, 2022 Researchers in Japan believe that it may be possible to predict tsunamis faster by tracking the atmospheric disturbances caused by the airwaves they create and the errors in the positional information supplied by GPS satellites. Examining the errors following eruption they found that it caused waves of air pressure to spread as far as Australia and Japan. These waves oscillated the lower part of the ionosphere and generated an electric field that was then transmitted at high speed to the upper ionosphere. They detected the electron changes much earlier than the air pressure waves that caused […]
Category Archives: Volcanoes
Tonga Volcano Blasted Out Pressure Waves “Very Close to The Theoretical Limit”
Science Alert July 1, 2022 The initial explosion and subsequent plume triggered atmospheric waves which propagated around the world multiple times. An international team of researchers (UK, USA – industry, University of Massachusetts Lowell, Virginia Tech, University of Colorado Boulder, NASA Goddard Space Flight Center, Catholic University of America, Germany, Australia, France) show the details of this response, using a comprehensive set of satellite and ground-based observations to quantify it from surface to ionosphere. A broad spectrum of waves was triggered by the initial explosion, including Lamb waves propagating at phase speeds of 318.2±6 ms-1 at surface level and between […]
Scientists provide explanation for exceptional Tonga tsunami
Phys.org June 13, 2022 The colossal eruption of the Hunga Tonga-Hunga Ha’apai volcano and ensuing tsunami is the first global volcano-triggered tsunami recorded by modern, worldwide dense instrumentation, thus providing a unique opportunity to investigate the role of air-water coupling processes in tsunami generation and propagation. An international team of researcher (Portugal, UK, USA – Columbia University, Spain) used sea-level, atmospheric and satellite data from across the globe, along with numerical and analytical models, to demonstrate that this tsunami was driven by a constantly moving source in which the acoustic-gravity waves radiating from the eruption excite the ocean and transfer […]
Satellite mission finds that Tonga volcanic eruption effects reached space
Phys.org May 10, 2022 Analyzing data from NASA’s Ionospheric Connection Explorer (ICON) mission and ESA’s Swarm satellites, an international team of researchers (USA – UC Berkeley, University of Colorado, Germany) found that in the hours after the eruption, hurricane-speed winds and unusual electric currents formed in the ionosphere. Upon reaching the ionosphere and the edge of space, ICON clocked the windspeeds at up to 450 mph. After the eruption, the equatorial electrojet surged to five times its normal peak power and dramatically flipped direction, flowing westward for a short period. According to the researchers this is something we’ve only previously […]
New method for detecting pre-eruption warning signals at Whakaari White Island and other active volcanoes
Phys.org April 20, 2022 Even with real-time geophysical monitoring, forecasting sudden eruptions is difficult, because their precursors are hard to recognize and can vary between volcanoes. An international team of researchers (New Zealand, Belgium) has described a general seismic precursor signal for gas-driven eruptions, identified through correlation analysis of 18 well-recorded eruptions in New Zealand, Alaska, and Kamchatka. The precursor manifested in the displacement seismic amplitude ratio between medium (4.5–8 Hz) and high (8–16 Hz) frequency tremor bands, exhibited a characteristic rise in the days prior to eruptions. They interpreted this as formation of a hydrothermal seal that enables rapid pressurization of […]
Tonga Islands: A seismic algorithm reveals the magnitude of the January 2022 eruption
Phys.org April 20, 2022 By analyzing the seismic waves researchers in France were able to design an algorithm that can detect and locate a volcanic eruption in near real-time and, using equations that describe explosive eruptions, assess its size. Until now, such an assessment required field work and took several weeks or months, since it was necessary to estimate the volume of ash and lava produced. The authors show that the Hunga Tonga eruption ejected a volume of around 10 km3, making it the largest explosive eruption of the twenty-first century, equivalent in strength to that of the devastating eruption […]
Ice Cores Reveal Huge Volcanic Eruptions, Bigger Than Anything in The Last 2,500 Years
Science Alert March 20, 2022 Large volcanic eruptions occurring in the last glacial period can be detected by their accompanying sulfuric acid deposition in continuous ice cores. Using such data an international team of researchers (Demark, Switzerland, Italy, UK, Canada) estimated the emission strength, frequency and the climatic forcing of large volcanic eruptions that occurred during the second half of the last glacial period and the early Holocene epoch. Due to limited data resolution and large variability in the sulfate background signal, they identified 1113 volcanic eruptions in Greenland and 737 eruptions in Antarctica within the 51 kyr period. They found […]
Tongan volcano eruption leaves scientists with unanswered questions [24 minutes]
Nature Podcast February 16, 2022 On the 15th of January, a volcano in the South Pacific Ocean erupted, sending ash into the upper atmosphere, and unleashing a devastating tsunami that destroyed homes on Tonga’s nearby islands. Now scientists are trying to work out exactly what happened during the eruption — and what it means for future volcanic risks. Podcast
Why the Tongan eruption will go down in the history of volcanology
Nature.com February 19, 2022 The eruption that devastated Tonga on 15 January lasted just 11 hours, but it will take years for scientists to work out exactly what happened during the cataclysmic explosion — and what it means for future volcanic risks. Geochemical analysis of that material, described in a paper found that the 2009 and 2014–15 eruptions involved molten rock that had not risen recently from the great depths of Earth’s mantle. Instead, it had spent some time in a magma chamber located 5–8 kilometres deep in Earth’s crust and gone through some tell-tale chemical changes before ultimately erupting […]
Tonga Volcanic Explosion Was Strong Enough to Send Gravitational Waves to the Atmosphere
Nature World News January 22, 2022 Tonga’s population has suffered a huge disaster due to a volcanic eruption and following tsunami on the South Pacific Island country. On January 15, 2022, the volcano that had been erupting since December 2021 burst spectacularly. The shock wave from the blast was so powerful that it was detected as far away as Antarctica according to Comprehensive Nuclear-Test-Ban Treaty Organization in Vienna, Austria, which oversees an international network of remote monitoring stations. Even days after the eruption the network can still detect the faint echo of the shock wave as it orbits Earth’s atmosphere. […]