1886 eruption of Mount Tarawera

Shortly after midnight on the morning of 10 June 1886, a series of more than 30 increasingly strong earthquakes were felt in the Rotorua area[2] and an unusual sheet lightning display was observed from the direction of Tarawera. At around 2:00 am,[3] a larger earthquake was felt and followed by the sound of an explosion. By 2:30 am Mount Tarawera's three peaks had erupted, blasting three distinct columns of smoke and ash thousands of metres into the sky[4] At around 3.30 am, the largest phase of the eruption commenced; vents at Rotomahana produced a pyroclastic surge that destroyed several villages within a 6-kilometre (3.7 mi) radius, and the Pink and White Terraces appeared to be obliterated.

Approximately 2 cubic kilometres (0.5 cubic miles) of tephra was erupted,[5] more than Mount St. Helens ejected in 1980. Many of the lakes surrounding the mountain had their shapes and areas dramatically altered, especially the eventual enlargement of Lake Rotomahana, the largest crater involved in the eruption, as it re-filled with water. The rift created during the eruption extends 17 kilometres (11 mi) across the mountain, Lake Rotomahana and through the Waimangu Volcanic Rift Valley.

The eruption was heard clearly as far away as Blenheim and the effects of the ash in the air were observed as far south as Christchurch, over 800 kilometres (497 mi) away. In Auckland the sound of the eruption and the flashing sky was thought by some to be an attack by Russian warships.

The eruption split the mountain and created the Waimangu Volcanic Rift Valley, which lies at the south-western end of the 17-kilometre (11 mi) rift created on 10 June 1886. The famed Pink and White Terraces, natural wonders of New Zealand, were until 2017 thought destroyed. Recent research using a forgotten 1859 survey has suggested possible locations of the Pink and White Terraces.[6][7] A small portion of the Pink Terraces was reportedly rediscovered under Lake Rotomahana 125 years later.[8] In 2017, using a lost 1859 survey of the old lake and terraces, researchers finally georeferenced the old Lake Rotomahana and the original Pink and White Terrace locations.[9][10]

Mount Tarawera was made up of three peaks which erupted one after the other. The first one to erupt was the Wahanga peak (located to the north), the next was Ruawahia (situated in the middle), and the last one was Tarawera (the southern peak). The Tikitapu bush was completely covered under the ash and the surrounding forests were flattened by the blasts.[11]

The land was covered with millions of tonnes of volcanic ash, mud and debris on average 20 metres (66 ft) thick.[12]

Although the official contemporary death toll was 153, exhaustive research by physicist Ron Keam only identified 108 people killed by the eruption. Much of the discrepancy was due to misspelled names and other duplications. Allowing for some unnamed and unknown victims, he estimated that the true death toll was 120 at most.[3][13] Some people claim that many more people died.[14]

The Māori settlements of Moura, Te Koutu, Kokotaia, Piripai, Pukekiore, Otuapane, Te Tapahoro, Te Wairoa, Totarariki, and Waingongoro were buried or destroyed. The official death toll was reported as 150, and many more were displaced, making the eruption the most deadly in New Zealand history.[15] Some of the local survivors at Te Wairoa took shelter in a Māori meeting house, a wharenui, named Hinemihi, which was later taken to England and erected in the grounds of Clandon Park, the seat of the 4th Earl Onslow, who had been governor-general of New Zealand at the time.

Te Wairoa is now a tourist attraction called "The Buried Village". Many people survived by sheltering in Te Wairoa's stronger buildings.[1]

• List of volcanoes in New Zealand
• Volcanology of New Zealand