Scientists have said the Tonga volcano that erupted under the sea in January set a record. The Tonga-Hunga Ha'apai volcano was the biggest explosion ever recorded using modern technology. It was also the biggest to happen in the past 150 years. The scientists said it may have been as large as the Krakatoa eruption that took place in 1883. Researcher Dr Robin Matoza said: "Tonga was a truly global event, just as Krakatoa was. But we've now got all these geo-physical [recording] systems, and they recorded something that was really [unmatched] in the modern data."

The volcanic eruption sent shock waves and tsunami waves around the world. People heard sonic booms 10,000km away in Alaska. The eruption even lifted clouds in the sky in the UK, which is 16,500km from Tonga. UK scientists reported the sudden disappearance of clouds. One UK scientist said the atmosphere was "a remarkably interconnected thing". He said: "What happens on one side of the planet can [spread] around to the other side at the speed of sound." NASA has said the volcano's effects reached space. The volcano could have affected the weather in space.