Late on January 15 last year, people across the Pacific, from New Zealand to Alaska, heard a massive boom when a submarine volcano exploded 65km north of Tonga’s main island, Tongatapu. Air-pressure sensors as far away as Iceland in the North Atlantic picked up the atmospheric shockwave as it spread in all directions and circum-navigated the globe.
Hunga Tonga-Hunga Ha’apai erupted with an intensity Nasa described as hundreds of times more powerful than the largest nuclear bomb ever detonated. It shot a plume of volcanic ash, gas and water vapour 58km up, beyond the top layers of Earth’s atmosphere
