A common Pacific myth tells us that Oceania’s many islands were either ‘fished up’ from the seas or ‘thrown down’ from the heavens. The undersea Hunga-Tonga-Hunga-Ha'apai volcano, which erupted with such force on 15th January, fits both stories. It was raised up when a relatively small 2015 eruption left layers of ash that formed a land platform joining the islands of Hunga-Tonga and Hunga-Ha'apai. The freshly combined islandsthen expanded in size in early 2021 while magma filled the craters below the surface, but now, with the volcano having unleashed its wrath, the land bridge has collapsed beneath the waves leaving the two now much shrunken islands again separated: fished up and then cast down.
After the eruption, a mushroom cloud of gas rose 30 kilometres into the atmosphere. It was visible from space. 400,000 lightning bolts pierced the sky as ash and atmospheric ice collided generating electrical charges. Magma blasts full of volcanic gas sent sound waves rippling outwards at supersonic speeds. These could be heard as far afield as Alaska. The resulting tsunami swept across the Pacific Ocean hitting the coasts of the Americas, New Zealand and Japan. On Tonga’s main island, Tongatapu, British women Angela Glover, owner of a dog sanctuary, was carried away in the rising seas as she tried to rescue her animals. Two further deaths have since been reported in the Ha’apai Islands. Another two people were drowned in Northern Peru.
The Hunga-Tonga-Hunga-Ha'apai volcano is situated along the Tonga trench, where the Pacific tectonic plate veers downwards beneath the Indo-Australian plate, forcing magma upwards. It is part of an unstable tectonic fault-line that stretches from New Zealand through Tonga and Melanesia, up to Japan and down the west coast of the Americas. This part of the world accounts for 75% of the world’s volcanoes. Previous smaller discharges from the Hungas in 2009 and 2015 occurred at the uplifted edge of the caldera, generating smaller explosions as hot magma hit the cold water, but the latest eruption likely came from the caldera itself, which has remained below sea level. This volcano erupts on such a huge scale only once around every thousand years, with the last mega-events occurring in AD 200 and AD 1100.
Volcanic and seismic activity have long been a regular part of the lifeworld of Pacific peoples. The Papua New Guinea islands have witnessed numerous episodes of ancient population extinction due to volcanic activity, with big eruptions at Rabaul in 1878, 1937 and 1994. Other active volcanoes on the Ring of Fire include Taupo in New Zealand, where holidaymakers nowadays lounge on their deck chairs admiring the gentle waters of the large freshwater lake that now fills the ancient caldera oblivious to the vast magma chamber lurking 6-8 km beneath. Taupo was the world’s last magnitude 8 supervolcanic eruption, which sent up around 30 cubic kilometres of pumice and ash into the atmosphere some 22,600 years ago, well before humans arrived in New Zealand. It remains active and threatening. Other volcanoes have more recently disrupted life in the ‘land of the long white cloud’. 22 people were killed on New Zealand’s Whakaari/White Island after an eruption in 2019.
The Tongan government intends to evacuate people from some of the smaller ash-covered islands close to the Hungas. Meanwhile, rehabilitation is proceeding at the airport, where people have been seen armed with shovels and wheelbarrows diligently sweeping ash from the runway to allow aircraft aid deliveries to land. The new Prime Minister, Siaosi Sovaleni, who was sworn into office only in December, will have his work cut out to finance the reconstruction not least because his government is deeply indebted to China. He will need the fortitude of Maui Kisikisi, the fabled Tongan hero believed to have drawn up the islands from the deep using a magic fishhook.
Jon Fraenkel is Professor of Comparative Politics at Victoria University of Wellington.