Smartphone sensors spotted Tonga volcano from Hawaii

The explosion of the Hunga Tonga-Hunga-Ha’apai submarine volcano on January 15 was recorded by a smartphone-based infrasound app from the University of Hawaii at Manoa.

This shows that these devices can record large explosions from thousands of kilometers away, according to the Infrasound Laboratory, based in the School of Earth and Ocean Sciences and Technology (SOEST) of this university.

Until the Tonga event, the 2013 Chelyabinsk meteor over Russia was the largest recorded atmospheric explosion in the digital age. The blast intensity of meteorite impacts and volcanic eruptions is commonly reported relative to the energy of a trinitrotoluene (TNT) equivalent blast. With an estimated yield of 500 kilotons of TNT, the shock wave from the Russian meteorite was recorded by conventional geophysical monitoring systems across the Earth.

After reviewing emerging smartphone technology of the time, Milton Garcés, director of the Infrasound Laboratory, postulated that onboard microphones and barometer sensors could also record such signals.

“Both smartphones and traditional networks captured unique and extraordinary infrasound measurements in Hawaii from the Tonga eruption”Garces said in a statement.

“Smartphones not only captured the direct arrival, but also the multiple circumglobal transits of the air wave. Nine years after the Russian meteorite, the Tonga explosion proved that smartphone sensors can record large explosions thousands of miles away.” he added.

In 2014, the US Department of State supported the development of Garcés’ RedVox Recorder smartphone app to detect infrasound from atmospheric bursts. More recently, in support of nuclear non-proliferation goals, research funding from the US Department of Energy’s National Nuclear Security Administration has enabled Garcés to expand its smartphone technology and enhance capabilities to measure various sound and vibration signatures near the Earth’s surface, as well as in the upper atmosphere and ocean.

Teams of scientists, engineers, programmers, students, and citizens have helped mature the technology and make it available to the public. The free RedVox Infrasound Recorder app is available from the Apple App and Android Play stores and runs on most modern smartphones.

“Ubiquitous sensors, such as smartphones, can take our infrasound monitoring potential to the next level,” Garcias said. “For example, from calculations based on pressure data collected through the app and traditional sensors, we can estimate that the Tonga explosion was larger than Tsar Bomb, which at 50 megatons was the nuclear weapon. most powerful ever tested. It is probably closer to the 1883 Krakatoa explosion, which reached 200 megatons.”

“That something as evanescent and intangible as infrasound can last for days is remarkable, and we have a free smartphone app that can record these primary signals in the deepest part of sound. This was not possible 10 years ago,” she concluded.

Source: Elcomercio

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