Posts tagged White Island

White Island – NZ’s most active volcano

Growing up in NZ’s volatile geography,  we are both fascinated by volcanos so White Island has been on our bucket list for a while. White Island or Whakaari, is NZ’s most active cone volcano and is an active andesite stratovolcano, 48 km offshore from Whakatane.  It has been in a nearly continuous state of releasing volcanic gas since written records began with the visit of James Cook in 1769.  White Island is roughly circular, with most of it below the water, only 321m sticks out above the ocean, forming a roughly circular island which is about 2 km wide.

The eruptions produce both lava flows and explosive eruptions of ash.  Activity is continuously monitored by volcanologists from GNS (Geologic and Nuclear Sciences) via monitoring equipment including seismographs, magnetometers, surveillance cameras and quarterly visits.

The alert level for White Island is usually 1 or 2 (which is the high alert end of the 1-5 scale). Mostly activity is steaming fumeroles and boiling mud, although occasionally ash belches and the eruption of 1981-83 created a crater lake.  

The crater lake is extremely acidic, with a PH of -0.7 which is an indication of what a challenging environment it must have been for the men working at the sulphur mine.  In an indication of how dynamic the environment is, a new geyser appeared in the crater lake as the lake level rose, just a day or two prior to our visit.  This resulted in satisfying clouds of steam from the crater lake.

Sulphur mining was attempted there, as sulphur is used in many manufacturing processes, but after a number of people died on the island, including the most disastrous event when a lahar swept away most of the factory and all 12 of the workers in 1914, mining was largely abandoned.  These buildings date back to the 1920’s with the final attempt at extracting sulphur on a commercial scale.

Nowadays, White Island is the main tourism attraction from Whakatane.  Boat trips take large groups of tourists to the Island, and several helicopter companies also operate tours to the island.  Many of the visitors are international, fascinated by the thermal geology, the surreal landscapes and the open access to the floor of the crater which makes it possible for groups of tourists to inspect the fumeroles, sulphur formations and hot streams at close quarters.  The tour groups are regaled with stories of tragedy during the attempts to industrialise sulphur processing, rather than the more scientific commentary we received while visiting volcanos elsewhere.

10th August, 2018.