Tonga eruption was so intense it caused the atmosphere to ring like a bell

Posted: January 25, 2022 by oldbrew in atmosphere, satellites, volcanos, waves

The atmospheric plume from an underwater volcano eruption in the Pacific nation of Tonga is pictured from the International Space Station as it orbited 269 miles above the Pacific Ocean northwest of Auckland, New Zealand [image credit: NASA / Kayla Barron @ Wikipedia]

This NASA animation leaves little room for doubt about how powerful the Tonga event was. The very low-frequency sound waves it produced were first predicted by Laplace over 200 years ago, as the article below explains.
– – –
The Hunga Tonga-Hunga Ha’apai eruption reached an explosive crescendo on Jan. 15, 2022, says Kevin Hamilton @ The Conversation (via

Its rapid release of energy powered an ocean tsunami that caused damage as far away as the U.S. West Coast, but it also generated pressure waves in the atmosphere that quickly spread around the world.

The atmospheric wave pattern close to the eruption was quite complicated, but thousands of miles away it appeared as an isolated wave front traveling horizontally at over 650 miles an hour as it spread outward.

NASA’s James Garvin, chief scientist at the Goddard Space Flight Center, told NPR the space agency estimated the blast was around 10 megatons of TNT equivalent, about 500 times as powerful as the bomb dropped on Hiroshima, Japan, during World Word II.

From satellites watching with infrared sensors above, the wave looked like a ripple produced by dropping a stone in a pond.

The pulse registered as perturbations in the atmospheric pressure lasting several minutes as it moved over North America, India, Europe and many other places around the globe.

Online, people followed the progress of the pulse in real time as observers posted their barometric observations to social media. The wave propagated around the whole world and back in about 35 hours.

I am a meteorologist who has studied the oscillations of the global atmosphere for almost four decades. The expansion of the wave front from the Tonga eruption was a particularly spectacular example of the phenomenon of global propagation of atmospheric waves, which has been seen after other historic explosive events, including nuclear tests.

This eruption was so powerful it caused the atmosphere to ring like a bell, though at a frequency too low to hear. It’s a phenomenon first theorized over 200 years ago.

Krakatoa, 1883

The first such pressure wave that attracted scientific attention was produced by the great eruption of Mount Krakatoa in Indonesia in 1883.

Continued here.

  1. […] Tonga eruption was so intense it caused the atmosphere to ring like a bell […]

  2. Gamecock says:

    ‘though at a frequency too low to hear.’

    Then it didn’t ring like a bell.

  3. Gamecock says:

    ‘though at a frequency too low to hear.’

    Then it didn’t ring like a bell.

    I wonder if this thing is going to affect GMT and CO2 concentration like Pinatubo did.

  4. oldbrew says:

    Continent-Size Pressure Waves Are Rippling Through Earth’s Atmosphere

    Scientists first theorized about the waves 220 years ago. In June, they finally found solid evidence.
    AUGUST 16, 2020

    Laplace didn’t name these waves or work out their behavior in detail, but modern atmospheric scientists now describe them as “normal modes”—waves that resonate like the ringing of a bell. The simplest mode raises the pressure in one hemisphere and lowers it in the other. More energetic modes create checkered patterns of smaller zones of high and low pressure. They race around the globe, mainly eastward and westward, at speeds exceeding those of most passenger planes.
    . . .
    “Atmospheric modeling of the pencil-and-paper kind was pretty damn crude until the 20th century, and yet Laplace managed to do this,” says David Randall, an atmospheric scientist at Colorado State University. “I think it’s astounding.”

  5. oldbrew says:

    JANUARY 19, 2022
    A volcanic eruption in 2020 led to hours-long thunderstorm
    by Geological Society of America

    A study conducted by scientists at the U.S. Geological Survey, the National Oceanic and Atmospheric Administration, and Vaisala Inc., published yesterday in the Geological Society of America’s journal Geology, discusses how advances in global lightning detection have provided novel ways to characterize explosive volcanism. Lead author Alexa Van Eaton says, “It’s the perfect storm—explosive eruptions can create lightning that is detected around the world.”
    . . .
    On Sat., 15 Jan. 2022, a massive volcanic eruption from the submarine volcano in Tonga, known as Hunga Tonga-Hunga Ha’apai, occurred. It sent a tsunami across the entire Pacific Ocean while a giant ash cloud spread out overhead, producing record-breaking amounts of volcanic lightning. Van Eaton and colleagues’ Geology paper explains how such water-rich volcanic plumes become electrically charged.
    – – –
    JANUARY 19, 2022
    EXPLAINER: Why Tonga eruption was so big and what’s next

    The magma inside the volcano was under enormous pressure and had gasses trapped within it. A fracture in the rock likely induced a sudden drop in pressure, allowing the gas to expand and blast the magma apart. Cronin said the crater was sitting about 200 meters (650 feet) below the sea surface, a kind of Goldilocks depth for a big explosion in which seawater pours into the volcano and turns instantly into steam, adding to the rapid expansion and energy of the explosion. Any deeper and the extra pressure of the water would have helped contain the eruption.

  6. […] Tonga eruption was so intense it caused the atmosphere to ring like a bell […]

  7. oldbrew says:

    JANUARY 26, 2022
    Tonga eruption is one for the record books

    The recent violent volcanic eruption on the Pacific island nation of Tonga is believed to be one of the strongest ever recorded, and future eruptions could be possible, according to a Texas A&M University geophysicist.

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