Phys.org September 12, 2023 An international team of researchers (UK, Italy, Germany, USA – University of Alaska, Cornell University) studied 600 glaciers located on and near 37 ice-clad volcanoes in South America. The results demonstrated glacier sensitivity to volcanic heat. They distinguished between “volcanic glaciers” and “proximal glaciers” and calculated their equilibrium line altitudes (ELAs). For each ice-clad volcano, they compared the ELAs of its volcanic glaciers to those of its proximal glaciers and established volcanic thermal anomaly. Results highlighted the impact of volcanic heat on glacier elevation; emphasized the need to exclude glaciers on, or near, volcanoes from glacier-climate […]
Category Archives: Volcanoes
Tonga volcano unleashed fastest ever undersea flows: study
Phys.org September 7, 2023 In December 2021, an undersea volcano in the southern Pacific Ocean, the Hunga Tonga–Hunga Ha‘apai (Hunga volcano) began erupting. In January 2022 the eruption reached a powerful climax, triggering atmospheric waves that traveled around the globe and a tsunami that swept across the Pacific Ocean. An estimated 75% of Earth’s volcanoes are underwater, and 20% of all fatalities caused by volcanic eruptions since 1600 CE have been associated with underwater volcanism. Yet, explosive underwater eruptions are poorly understood. An international team of researchers (UK, New Zealand, Kingdom of Tonga, Australia, USA – industry) reported that volcanic […]
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 […]
The Tonga volcano eruption caused a ‘super bubble’ in Earth’s ionosphere, disrupting satellite navigation
Phys.org May 30, 2023 The Hunga Tonga Volcano eruption launched waves which generated traveling ionospheric disturbances (TIDs) in the ionosphere, which are known to adversely impact radio applications such as Global Navigation Satellite Systems (GNSS). One such GNSS application is Precise Point Positioning (PPP), which can achieve cm-level accuracy using a single receiver, following a typical convergence time of 30 min to 1 hr. An international team of researchers (Australia, USA – Boston College, Vietnam) used a network of ionosondes located throughout the Australian region in combination with GNSS receivers to explore the impacts of the volcano eruption on the […]
Researchers reveal disturbances of Tonga volcanic eruption
Phyus.org March 3, 2023 The effects of volcanic eruptions on the ionosphere have been well studied, however, evidence for the anticipated upper atmospheric neutral variations and their exact extents of change are rarely available. An international team of researchers (China, Germany, USA – MIT) found dramatic thermospheric disturbances following the 15 January 2022 Tonga eruption. The GRACE-FO and Swarm-C observations from the accelerometers exhibited three successive thermospheric density waves at ∼500 km altitudes propagating concentrically across the globe at 200–450 m/s phase speed and two of the three waves converged at the antipode of the epicenter. A large-scale and long-lasting […]
Ice cores show even dormant volcanoes leak abundant sulfur into the atmosphere
Phys.org February 3, 2023 Sulfate aerosols are particles in the atmosphere that have a net cooling effect on the climate. One of the most uncertain aspects of climate modeling is the abundance of sulfate aerosols during the preindustrial era. Without knowing the amount of sulfate aerosols during the preindustrial times, it is difficult to estimate how much anthropogenic sulfate aerosols have offset warming from anthropogenic greenhouse gases. A team of researchers in the US (University of Washington, South Dakota State University, University of New Mexico, Michigan Technological University) examined preindustrial sulfate aerosols in a Greenland ice core. They found that […]
A year on, we now know why the Tongan eruption was so violent. It’s a wake-up call to watch other submarine volcanoes
Phys.org January 13, 2023 An international team of researchers (Tonga, New Zealand) studied the texture and chemistry of the erupted particles to find clues about the event’s violence. Isotopic “fingerprinting” showed at least three different magma sources were involved. Two magma bodies were older and resident in the middle of the Earth’s crust, the younger one joined shortly before the eruption. The mingling of magmas caused a strong reaction, driving water and other “volatile elements” out of solution and into gas. This created bubbles and an expanding magma foam, pushing the magma out vigorously at the onset of eruption. The […]
Signals from the ionosphere could improve tsunami forecasts
Phys.org December 12, 2022 Acoustic-gravity waves propagated by the eruption and tsunami caused global complex ionospheric disturbances. Researchers at the University of Washington studied the nature of the perturbations from Global Navigation Satellite System observables over the southwestern Pacific. After processing data from 818 ground stations, they detected supersonic acoustic waves, Lamb waves, and tsunamis, with filtered magnitudes between 1 and 7 Total Electron Content units. Phase arrivals appeared super positioned up to ∼1,000 km from HTHH and were distinct by ∼2,200 km. Within ∼2,200 km, signals had an initial low-frequency pulse that transitioned to higher frequencies. They found the […]
The Yellowstone Supervolcano Holds Way More Liquid Magma Than We Realized
Science Alert December 8, 2022 An obvious but key requirement for an eruption is the presence of magma. This magma also needs to be distributed so that it can mobilize and erupt as a coherent body. A key issue for eruption hazard assessment is to ascertain how much magma is below the surface and where. Researchers at UC Davis modeled seismic data to image melt beneath the Yellowstone Caldera. They concluded that more melt is present than had been recognized, and it is located at shallow depths in the crust. But the melt fraction they estimated is substantially lower than […]
Monitoring ‘frothy’ magma gases could help evade disaster
Phys.org November 21, 2022 Researchers in Japan repeatedly measured isotopic compositions of noble gases and CO2 in volcanic gases sampled at six fumaroles around the Kusatsu-Shirane volcano (Japan) between 2014 and 2021 to detect variations reflecting recent volcanic activity. The synchronous increases in 3He/4He at some fumaroles suggested an increase in magmatic gas supply since 2018. The increase in magmatic gas supply was also supported by the temporal variations in 3He/CO2 ratios and carbon isotopic ratios of CO2. The 3He/40Ar* ratios showed significant increases in the period of high 3He/4He ratios. The temporal variation in 3He/40Ar* ratios may reflect changes […]