Rotorua volcanologist Brad Scott is one of two GNS Science staff helping the people of Vanuatu as four volcanoes cause concern on the island.
Mr Scott and Nico Fournier are helping the Geohazards Division of the Vanuatu Meteorological Geohazards Department (VMGD). VMGD monitors active volcanoes in Vanuatu.
"Currently there are two volcanoes in eruption and two others experiencing volcanic arrest [waking up]," Mr Scott said.
"The team here is small and the current burst of extra activity has stretched the capability. We have been working with VMGD for the past four years to build capability through an MFAT aid programme.
"The VMGD formally asked New Zealand for assistance, hence Nico and I being here to help."
The pair flew to Vanuatu 11 days ago, about the same time the alert for Vanuatu's northern island of Ambae increased to level four - the second highest - as the Manaro Voui volcano continued to spit rock and ash into the air.
Since then a flotilla of small boats, barges and supply ships have been used to evacuate about 11,000 people. The alert has now been dropped to level three but the Vanuatu Government have yet to determine whether those evacuated can return home.
The decision may take some time as ash fall has killed crops and contaminated water on the island.
Meanwhile international support is ongoing. The New Zealand Defence Force flew in two more tonnes of supplies on Friday, taking the total to more than 12 tonnes and including hygiene kits, portable toilets and tarpaulins.
Mr Scott said he and Mr Fournier had not had much to do with the evacuations.
"We have been involved in observation flights, data analysis, helping prepare science reports, briefings, press releases and social media content," he said.
"The Ambae volcano remains the primary concern. Through September the volcano was waking up, explosions and some of the larger events created ash falls on some local villages. Lava reached the surface around September 22-23 and there was a lot of uncertainty over how the eruption would develop.
"The eruption has now stabilised and the threat of a larger eruption is now less."
Mr Scott said he had been involved in similar responses in Vanuatu in 1987, 2005 and 2009 when other volcanoes were in eruption.
Foreign Minister Gerry Brownlee yesterday announced a further $700,000 of support to Vanuatu for communities impacted by the evacuation from Ambae.