Hunga Tonga–Hunga HaʻapaiADDPMP786
The Hunga Tonga–Hunga Haʻapai most recent eruption in January 2022 was the largest volcanic eruption in the 21st century and the largest eruption since the 1883 eruption of Krakatoa in the Sunda Strait between the islands of Java and Sumatra, Indonesia.
On 20 December 2021, the volcano erupted, causing a large plume visible from Nukuʻalofa at the time. Explosions could be heard up to 170km (110 miles) away. The initial eruption continued until 2am on the 21st of December. Activity continued, and on 25 December, satellite imagery showed that the island had increased in size. As volcanic activity decreased, it was declared dormant on 11 January before only to become active again on 14 January after the volcano created another ash cloud. The Tongan government subsequently issued a tsunami warning. The next day, the volcano violently erupted again, about seven times more powerfully than the eruption on 20 December 2021. The initial volcanic plume rose to 58km (36 miles), the greatest height ever reported for a vapour plume. The eruption set off a massive atmospheric shockwave travelling at about 300m (1,000ft) per second. There were numerous reports of loud booms across Tonga and in other countries such as Fiji, and as far away as New Zealand and Australia. A boom was heard in Alaska, 10,000km (6,213 miles) from the source and seven hours after the eruption. The Met Office in the UK also detected shockwaves. The eruption also generated a tsunami that reached as far as the coasts of Japan and the Americas and a volcanic plume that reached 58km (36 miles) into the mesosphere.
Before the 2022 eruption, Hunga Tonga–Hunga Haʻapai volcano lay almost completely underwater with the exception of two small volcanic islands, Hunga Tonga and Hunga Haʻapai, which were, respectively, the remnants of the northern and western rim of the volcano’s caldera. As a result of the volcano’s history, the islands were merged by a volcanic cone in an eruption in 2014–2015 and have existed as a single landmass since then. However, they were separated again by the 2022 eruption, and mostly destroyed; only small parts of the two islands remain.