Tonga: Volcanic Eruption and Tsunami

 

 A large eruption of the Hunga Tonga Hunga Ha-apai underwater volcano in the evening of 15 January (at 17:26 local time) caused a tsunami and ash fall in Tonga (total pop. 105,000 people). The volcanic eruption has continued throughout the day with satellite imagery indicating a 5km wide plume of ash, steam and gas rising into the air 20km above the volcano. The ash plume was observed moving northeast over the islands of Ha’apai and is currently proceeding in a westerly direction away from Tonga. The eruption was one of the biggest in Tonga in the past 30 years. During the initial eight-minutes, it was so violent it could be heard as "loud thunder sounds" in Fiji, more than 800km away.

No additional eruptions were recorded since yesterday’s update. However, further volcanic activity cannot be ruled out. The ash cloud has slowly moved on in a north-westerly direction. Elsewhere in the Pacific (Fiji, Samoa, Vanuatu, Solomon Islands) tsunami warnings have been lifted and no serious impact has been reported so far apart from some limited flooding [..] For Tonga, the tsunami of Saturday has caused yet to be detailed damage of buildings and infrastructure. Nuku’alofa, Tonga’s capital, is covered with a two-centimetre-thick layer of volcanic ash and dust. However, the situation in the city is calm and stable and first clean-up efforts are being made. Nuku’alofa’s waterfront is seriously damaged with rocks and debris pushed inland by the tsunami. Overall, there appears to be significant infrastructural damage around Tongatapu, the main island. There had been no contact from the Ha’apai Group of islands with particular concern about two small low-lying islands – Mango and Fonoi. An active distress beacon had been detected from Mango. 

An initial assessment from the Government of Tonga is that 100 houses were damaged and 50 destroyed in Tongatapu. No evacuation centres are open in Tongatapu, the people who were displaced (numbers not confirmed as of now) are staying with extended families. There are 89 people in evacuation centres in ‘Eua. Information from outer islands is still very scarce. In Ha’apai and Vava’u islands, communication lines remain down and concerns exist regarding damage to low lying island in this group. Three deaths have been recorded so far. Preliminary information from the Tongan Ministry of Agriculture indicates that the damage in the agricultural sector, and particularly of root crops, is less severe than initially feared. Due to thick ash cover is thicker than anticipated (between 5 and 10 cm) and will need more time to be cleared away. Planned relief flights (from Australia and New Zealand, for the time being) are on stand-by.