Labels

New Zealand Volcanoes and their specific traits

Auckland Volcanic Field
  • Volcanic Field.
  • Last erupted: 600 years ago.
  • Multiple potential eruption sites.
  • Scattered across New Zealand's largest city, Auckland.
  • In close range of sea water.
  • Considered still active.
  • "Low odds, high consequences".
Mayor Island
  • Shield volcano, calderas, lava domes, and pyroclastic cones.
  • Last erupted: 6,300 years ago
  • Likely caused a tsunami by pouring pyroclastic flows into the sea.
  • Produced tephra deposits that reached the mainland (said deposits covered up to 70cm high).
  • In very close range of sea water, meaning 
  • 50km offshore.
  • 52 eruptions over the past 130,000 years.
Ngauruhoe
  • Stratovolcanoes and pyroclastic cones.
  • Last erupted: 1975.
  • Volcanic ash/lava launched as far as 3km away.
  • "The most continually active" volcano in New Zealand.
  • Column of ash 13km above. Collapsed and landed later, covering the volcano in avalanching ash.
  • Close to Tongariro and Ruapeha. Chain reaction eruptions should be considered.
Kaikohe bay of islands
  • Volcanic fields of cone volcanoes and shield volcanoes.
  • Last erupted: 4,000 years ago.
  • Hot springs imply it is still active.
  • One eruption should be a warning sign for other volcanic sites potentially erupting, especially to the southeast.
  • Close enough to the Whangarei fields that a chain reaction eruption should be considered.
Ohakuri
  • Caldera.
  • Last erupted: 240,000 years ago
  • Erupted a few weeks after an eruption at Rotorua, 30km to the northeast. This implies that caution will have to be taken by civilians at nearby volcanoes as well. 
Rotorua
  • Caldera volcano.
  • Last erupted: 240,000 years ago
  • Eruption was followed weeks later by an explosion at the nearby Ohakuri. This implies that caution will have to be taken by civilians at nearby volcanoes as well.

Ruapehu
  • A stratovolcano, pyroclastic cones, and maar volcanoes.
  • Last erupted: 25 September 2007.
  • Three craters.
  • Launched rocks and water into Whakapapa (an active ski resort).

Taranaki
  • A stratovolcano and lava domes.
  • Last erupted: 1854.
  • Far away from any other eruption sites meaning chain reactions are not likely.

Tarawera
  • Cone volcano.
  • Last erupted: 1886.
  • Responsible for the death of 153 people during said eruption.
  • Opened a rift 17km long, which shot out ash and rocks for hours.
  • Contact between a nearby lake and some lava caused explosions, covering nearby villages and terraces in 1m of ash and mud.

Taupo
  • A caldera, lava domes, and fissure vents.
  • Last erupted: 1,800 years ago.
  • Previous eruption covered 20,000 square km, filling all rivers and lowlands in ash and pumice.
  • Eruptions from different sites.
  • Surrounded by water, which can result in explosions of mud and hot water.

Tongariro
  • Stratovolcanoes and pyroclastic cones.
  • Last erupted: 6th August & 21st November 2012.
  • Multiple volcanic cones.
  • Produced rock and ash straight upwards before falling down the side of the cone.

Whakaari/White Island 

  • Stratovolcanoes and lava domes.
  • Last erupted: 9th December 2019.
  • New Zealand's most active volcano.
  • The island is 48 km offshore.
  • Craters found off shore underwater.
  • Risk zone is on the island itself.
  • Caused heated gases to burn visitors.
  • Helicopters and jets were short in availability, leading to lifeboat usage. People who were burned by the gases couldn't climb down the ladders effectively.
Whale Island
  • Caldera and cone.
  • Last erupted: 9,000 years ago.
  • Produces steam which implies its active state.
Whangarei volcanic fields
  • Cone volcanoes.
  • Last erupted: 30,000 years ago.
  • Close enough to Kaikohe bay sites that a chain reaction of eruptions should be considered.

Sources:
Labels:

Comments

Post a Comment

Popular Posts