The Edge of Space Was Literally Shaken by a Massive Underwater Volcano
The explosion sent a plume of gas and ash over 50 kilometers (31 miles) into the air, far above the level of most weather and commercial jets. What really shocked scientists? It didn’t end there. A new study in AGU Advances describes how this massive eruption was able to shake a part the Earth that most volcanoes don’t touch. Using satellite data and atmospheric modeling, the researchers tested two culprits: lamb waves–pressure waves that “hug” Earth’s surface–and secondary gravity waves, which are generated when the first wave of, uh, waves, break apart high in the sky.
Simulations showing secondary gravity waves from the eruption. Graphic: Li et al. The researchers determined that secondary gravity waves caused the explosion, because their rapid movements and large magnitudes matched better with the satellite data they studied. The Tongan eruption produced a shockwave that was so powerful it caused the sky to shake. This wave, which was invisible to humans, was a rare clue that something terrible would happen. These studies show that the most violent volcanic eruptions can leave multiple fingerprints, if we know where to look. Scientists are now realizing that Earth’s most violent volcanic eruptions may leave multiple early footprints, if they know where to look. The more we know about how these events ripple outwards from their source, the better equipped we are to protect the technology we rely on.
