Hunga Tonga-Hunga Ha'apai, a submarine volcano located about 65 km NW of Tonga's capital Nuku'alofa, awakened mid-December 2014 after 5 years of sleep and started erupting from two new vents.
The eruption has created a new island between the existing islands of Hunga Tonga and Hunga Ha'apai, which is now joined to Hunga Ha'apai.
On January 19, the Pleiades satellite took this very high resolution image of the new island:
On January 15, 2015 Tonga's Lands, Survey and Natural Resources Ministry deputy secretary Taaniela Kula said the island was more than 1 km long, about 2 km wide and around 100 meters high. The eruption is similar to that at Hunga Ha’apai in 2009, but producing a larger volume of materials building the island.
"During our observations [on January 14] the volcano was erupting about every five minutes to a height of about 400 meters, accompanied by some large rocks. As the ash is very wet, most is being deposited close to the vent, building up the new island."
Hazardous surges of ash and steam were seen to spread out horizontally during eruptions, and these extended more than 1 km from the erupting vent.
Strong smells of volcanic gases were noticed on a few occasions, Kula said and added ash and acid rain is falling within 10 km of the eruption. "Leaves on trees on Hunga Tonga and Hunga Ha'apai have died, probably caused by volcanic ash and gases."
The video below was recorded on January 14 while investigating the eruption site.
Featured image: Copyright CNES 2015, Distribution Airbus DS / Spot Image