Most highly effective explosion on Earth had ‘thriller sign’ simply moments earlier than

A mysterious signal took place just moments before the most powerful volcanic explosion ever recorded, scientists have discovered.

A thunderous clap rocked the South Pacific in January 2022 – the strongest explosion to be recorded with modern instruments.

It came as underwater volcano Hunga Tonga-Hunga Ha’apai, located in the Tongan archipelago, violently exploded on January 15, 2022.

So powerful was the explosion, it was equivalent to hundreds of atomic bombs, and sparked the fastest underwater currents on record. It rated at least VEI-5 on the Volcanic Explosively Index (VEI), which puts it on par with the explosions of Mount Vesuvius in 79CE and Mount St. Helens in 1980.

However, two monitoring stations located faraway recorded a seismic wave around 15 minutes earlier, a new study revealed.

The study’s authors say the wave was a “seismic precursor” for the eruption, reports Science Alert, with the collapse in a weak section of oceanic crust below the volcano’s caldera wall, the trigger for both.

As a result of the collapse, seawater and lava flooded into the area between the volcano’s underground magma chamber and the sea floor, launching the eruption, the study’s authors said.

The fracture also triggered what is called a Rayleigh wave; a type of seismic wave that moves along a solid’s surface, causing movement. This Rayleigh wave moved along Earth’s surface and was detected 15 minutes before the main volcanic eruption which took place around 750 kilometres away.

Mie Ichihara, volcanologist at the University of Tokyo and study co-author said: “Early warnings are very important for disaster mitigation.

“Island volcanoes can generate tsunamis, which are a significant hazard.”

Modest volcanic grumblings were recorded in December 2021 and earlier in January 2022. A larger eruption to place on January 14 before the unrivalled explosion the next day.

The explosion catapulted 10 cubic kilometres (2.4) cubic miles) of volcanic material and sent 146 million metric tonnes of water vapour into the stratosphere, roughly 58,000 Olympic swimming pools’ worth. While in an isolated location, the blast launched out tsunamis that killed at least four people in Tonga, and a further two in Peru, 10,000kms away.

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