White Island, NZ Photo: Helen Cocker
White Island, NZ
Photo: Helen Cocker

By Helen

Over the past few days there has been increased levels of volcanic activity on White Island, New Zealand’s most active cone volcano.  This follows a period of lava dome eruption in December 2012 and an eruptive episode in August 2012.  In the last few days there has been an increase in the hydrothermal activity of the lake on the island and the aviation colour code has been changed to orange.

White Island, NZ Photo: Helen Cocker
White Island, NZ
Photo: Helen Cocker

However over the last day there has been a change in the style of the seismic activity at the island, which is continuously monitored.  White Island typically produces volcanic tremor, which is a continuous vibration caused by, but not limited to, gas escaping, moving magma, and ash eruptions.  The White Island seismic activity now has hybrid volcanic earthquakes as well.  These are produced by rock fracturing and magma moving in the volcano.

Regular monitoring of the gas output of the volcano is also used to get information about the concentration of gases emitted by the volcano, such as carbon dioxide, sulfur dioxide, and hydrogen sulfide.  The monitoring includes ground-based and air-based techniques.  A flight across the volcano is proposed for 25 January to see if the concentrations of these gases have changed.

White Island, NZ Photo: Helen Cocker
White Island, NZ
Photo: Helen Cocker

Eruptions on White Island can be explosive and can occur without any warning.

White Island lies 48 km off the eastern coast of the North Island of New Zealand and is the northern end of the Taupo Volcanic Zone, which also includes Tongariro and Ruapehu.  White Island is an example of a stratovolcano (composite cone), which is composed of lava and ash layers.  Most of the volcanic cone is underwater.  There used to be mining of sulfur on the island until the 1930s and remains of the factory can still be seen there.

White Island, NZ Photo: Helen Cocker
White Island, NZ
Photo: Helen Cocker

When the island has less volcanic unrest and the hazard has decreased it is an awesome place to visit! You can take a guided boat trip to the island from the town of Whakatane. The tour company will take you on a walking tour around parts of the active volcano to look at the acid lake and fumaroles.  They will also supply you with a hard hat and gas mask too so you look extra cool while on your tour.  You might be taken to Dino’s home on the island too – he lives by one of the webcams that monitors the island  – see if you can see him!  He’s so famous you can even find him on Facebook! You may also get to see dolphins or seals on the boat ride back.