Continuous eruptions are creating a new island between Hunga Tonga and Hunga Ha’apai, 65 km from Nuku'alofa, Tonga's Ministry of Lands and Natural Resources reports. “The eruption of ash and tephra continues, but in recent days the ash has been limited to low elevations,” their fourth advisory stated on January 15. 

A team from the ministry went out to observe the erupting volcano on January 14, and a second visit is planned for Thursday with two GNS volcanologists from New Zealand.

Taaniela Kula, the deputy secretary of MLNR released the fourth advisory on the event, tonight.

“A new island has been built by the eruption between the existing islands of Hunga Tonga and Hunga Ha’apai, and is now joined to Hunga Ha‘apai,” he stated.

The new island is more than 1 km wide, ~2km long and about 100 m high.

“During our observations the volcano was erupting about every five minutes. Dense ash was being erupted to a height of about 400 m, accompanied by some large rocks.

“Above about 1000 m, the eruption plume was almost exclusively steam. As the ash is very wet, most is being deposited close to the vent, building up the new island,” he stated.

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.

Ash fall and acidic rain was observed 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. No large rafts of pumice or other floating volcanic debris were observed. Strong smells of volcanic gases were noticed on a few occasions.”

Taaniela said that this eruption is similar to that at Hunga Ha’apai in 2009, but producing a larger volume of materials building the island.

Algal bloom

“It is unclear at this stage if there is any relationship between the eruption and a red algal bloom observed in seawaters around Tonga recently,”

Taaniela said that the MLNR advisories had been based on collective information provided by Tonga Broadcasting Commission, Tonga Meteorological Services, Tonga Airport Limited, NZ-Meteorological Services, His Majesty’s Armed Force, National Emergency Management Office, and Ministry of Lands and Natural Resources.

The site observation conducted on 14 January was sponsored by the New Zealand High Commission, who will support a second visit to the site today.

The eruption area is located approximately 65km NW of Vuna Wharf, Nuku'alofa, and ~70km SW of Nomuka Island.

Volcanic ash forecasting

Pilots have reported steam plumes from the Hunga Ha'apai and Hunga Tonga area, but substantial ash emission to the altitudes at which aircraft fly have not been observed for several days.

Airline flights

International flights resumed on the  January 14 after several days of cancelled flights. The domestic airline is currently also operating.

The eruption of ash and tephra continues, but in recent days the presence of ash has been limited to low elevations. 

Observations on 14 January 2015 confirms the location of the eruption that there is only one source of the eruption, a new island between Hunga Tonga and Hunga-Ha’apai.