Three easily measurable parameters can provide valuable information about the structure of volcanoes

Phys.org  August 31, 2023 Volcanoes exhibit a wide range of eruptive and geochemical behavior, which has significant implications for their associated risk. The suggested first-order drivers of intervolcanic diversity invoke a combination of crustal and mantle processes. To better constrain mantle-crustal-volcanic coupling, an international team of researchers (Ireland, Switzerland) used the Lesser Antilles to show that melt flux from the mantle, identified by proxy in the form of boron isotopes in melt inclusions, correlates with the long-term volcanic productivity, the volcanic edifice height, and the geophysically defined along-arc crustal structure. These features were the consequence of a variable melt flux […]

Half-century of cyclone data puts researchers on track to explore future risks

Phys.org  January 19, 2023 Tropical cyclones (TCs) with genesis in the Coral Sea present significant hazards to coastal regions in their surroundings. In addition, the erratic nature of TC tracks is not well understood in this region. Researchers in Australia grouped Coral Sea TC tracks over the last fifty years based on K-means clustering of the maximum wind-weighted centroids to extract valuable new cyclone power, track curvature and location related information to predict their behaviour. They assessed the TC track variance and curvature (sinuosity) and identified three well-defined clusters of TC tracks. The results showed differing predominant directions of TC […]

Deep learning can predict tsunami impacts in less than a second

Phys.org  December 27, 2022 An international team of researchers (Japan, New Zealand) leveraged the world’s largest and densest tsunami observing system to develop a method for a real-time tsunami inundation prediction based on machine learning. Their method utilizes 150 offshore stations encompassing the Japan Trench to simultaneously predict tsunami inundation at seven coastal cities stretching ~100 km along the southern Sanriku coast. They trained the model using 3093 hypothetical tsunami scenarios from the megathrust (Mw 8.0–9.1) and nearby outer-rise (Mw 7.0–8.7) earthquakes. Then, the model was tested against 480 unseen scenarios and three near-field historical tsunami events. The proposed model can […]

Shockwave caused by Tonga underwater eruption may help scientists predict future tsunamis

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 […]

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 […]

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 […]

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 […]

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 […]

Hidden magnitude-8.2 earthquake source of mysterious 2021 global tsunami

Phys.org  February 8, 2022 The 2021 August South Sandwich Island Mw 8.2 earthquake was a surprise, because it was initially reported as a magnitude 7.5 event at a deep depth (47 km) but generated a global-spreading tsunami that would only be expected for a larger and shallower event. By using seismic data researchers at Caltech revealed a hidden Mw 8.16 shallow slow event that happened between clusters of regular ruptures in the beginning and end. Although the slow event contributed 70% of the seismic moment, lasted three minutes, and ruptured a 200-km section of the plate interface, it is essentially […]

New type of earthquake discovered

Phys.org  December 6, 2021 A seismic slip loading has recently been proposed as a complementary mechanism to induce moderate-sized earthquakes located within a few kilometers of the wellbore over the timescales of hydraulic stimulation. However, aseismic slip signals linked to injection-induced earthquakes remain largely undocumented to date. An international team of researchers (Canada, Germany) has reported a new type of earthquake characterized by hybrid-frequency waveforms (EHWs). Distinguishing features from typical induced earthquakes include broader P and S-pulses and relatively lower-frequency coda content. Both features may be causally related to lower corner frequencies, implying longer source durations, thus, either slower rupture […]