page_title: Whakaari / White Island
section_title: Volcanology
hierarchical_section_title: Whakaari / White Island / Volcanology
caption_attribution_description: This SeaWiFS satellite image shows a long eruption plume coming from the White Island volcano in the Bay of Plenty, New Zealand on June 14, 2000. Considerable turbidity is also evident along the North Island's east coast.
context_page_description: Whakaari / White Island is an active andesite stratovolcano situated 48 km from the east coast of the North Island of New Zealand, in the Bay of Plenty. The island covers an area of approximately 325 ha, which is only the peak of a much larger submarine volcano.
  The island is New Zealand's most active cone volcano, and has been built up by continuous volcanic activity over the past 150,000 years. The nearest mainland towns are Whakatane and Tauranga. The island has been in a nearly continuous stage of releasing volcanic gas at least since it was sighted by James Cook in 1769. Whakaari erupted continually from December 1975 until September 2000, marking the world's longest historic eruption episode, according to GeoNet, and also in 2012, 2016, and 2019.
  Sulphur was mined on the island until the 1930s. Ten miners were killed in 1914 when part of the crater wall collapsed. The main activities on the island now include guided tours and scientific research. Access to the island is allowed only as a member of a tour run by a registered tour operator.
context_section_description: Whakaari / White Island lies in northern end of the Taupo Volcanic Zone. The Taupo Volcanic Zone forms the southernmost segment of the 2,800 km (1,700 mi)-long Tonga–Kermadec–Taupo volcanic arc system and the Lau Basin–Havre Trough–Ngatoro Basin back-arc basin system.
  For the past few thousand years, Whakaari / White Island has been the location for an open, highly reactive hydrothermal system. This hydrothermal system expresses itself as hot springs and mud pools, fumaroles, and acid streams and lakes. the present day centre for volcanic
  activity and outgassing is a large crater lake of boiling acidic waters located in the western
  subcrater. The intermixing mélange of marine waters, meteoric waters, and hot magmatic
  fluids generate acid brines, with ph as low as 2, that outgas and form numerous and often  transitory hot springs and mud pools, fumaroles, and acid streams and lakes. The crater lake of boiling acidic water, which occupies the western subcrater, appears to vary in volume due to changing meteorological conditions and fluctuating levels of hydrothermal activity.
  Although Strombolian activity occurred from the late seventies to the mid-eighties, explosive eruptions at Whakaari / White Island are typically phreatic or phreatomagmatic in style.  The lava flows, ash, and pyroclastic flows produced by historic and prehistoric eruptions are andesitic and dacitic in composition. These eruptions also produce discrete craters within crater-fill deposits of the Central Cone. Since 1826, there has been a minimum of 28 phreatic or phreatomagmatic eruptions. In addition, prehistoric eruptions have also extruded lava. The lava flows from these prehistoric eruptions are exposed crater walls of the Central Cone. Whakaari / White Island's frequent activity and easy access attract scientists and volcanologists as well as many tourists. For example, this volcano provides a readily studied example of the type of volcanic magmatic–hydrothermal system involved in the generation of porphyry copper deposits.
  Volcanologists from the GeoNet Project continually monitor the volcano's activity via surveillance cameras. Survey pegs, magnetometers and seismography equipment for early earthquake warnings via radio were installed on the crater walls in 1976. The island is typically on an alert level rating of 1 or 2 on a scale of 0 to 5; as "Level 2 is the highest alert level before an eruption takes place and indicates 'moderate to heightened volcanic unrest' with the 'potential for eruption hazards.'"  The alert level was moved from level 1 to level 2 on 18 November 2019.
  This volcano is monitored by the Deep Earth Carbon Degassing Project. At most times the volcanic activity is limited to steaming fumaroles and boiling mud.
  In March 2000, three small vents appeared in the main crater and began belching ash which covered the island in fine grey powder. An eruption on 27 July 2000 blanketed the island with mud and scoria and a new crater appeared. Major eruptions in 1981–83 altered much of the island's landscape and destroyed the extensive pōhutukawa forest. The large crater created at that time now contains a lake, whose level varies substantially.
  Between July and August 2012 the island showed signs of increased activity with lake and gas levels rising from inside the crater. On 5 August 2012 a minor eruption occurred, sending ash into the air. More eruptions have followed since.
  Ongoing volcanic activity and tremors on 25 January 2013 suggested another eruption was imminent. A small eruption occurred on 20 August 2013 at 10.23 am, lasting for ten minutes and producing mostly steam.
caption: Eruption plume stretching northeastwards from Whakaari / White Island as seen from space, June 2000
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