Taupo Volcanic Zone
Encyclopedia : T : TA : TAU : Taupo Volcanic Zone
The Taupo Volcanic Zone, or (TVZ), is an active volcanic area in the North Island of New Zealand. It is named after Lake Taupo, which is the flooded caldera of the largest volcano in the zone.
Activity
There are numerous volcanic vents and geothermal fields in the zone, with Mount Ruapehu, Mount Ngauruhoe and White Island erupting most frequently. The zone's largest eruption since the arrival of humans was that of Mount Tarawera in 1886. The Rotorua caldera produced its most recent giant eruption about 240,000 years ago, while Taupo erupted 800 cubic kilometers of material 26,500 years ago (800 times more material than the 1980 Mt St Helens eruption). This is possibly the Earth's largest volcanic eruption in recent geological time.The last major eruption from Lake Taupo was in 181 AD. It is believed to have first emptied the lake then followed that feat with a pyroclastic flow that covered about 20,000 square kilometres of land with volcanic ash. A total of 50 cubic kilometers is believed to have been ejected, and over 30 cubic kilometers of material is estimated to have been ejected in just a few minutes.
Extent of zone
The Taupo Volcanic Zone is about 50 kilometres wide and about 300 kilometres long and lies over a subduction zone in the earth's crust. Mount Ruapehu marks its southwestern end, while White Island is considered its northeastern limit. The subduction zone appears to extend further to the northeast, as along the line of the Taupo Volcanic Zone lie several undersea volcanoes known as the Rumbles and also the Kermadec Islands, with another caldera at Raoul Island. There is no volcanic activity to the southeast, although the subduction zone continues as far south as Kaikoura, where the plate boundary changes to continental collision which is uplifting the Southern Alps in the South Island. A subduction zone reappears southwest of Fiordland, at the southwestern corner of the South Island. For this reason the Taupo Volcanic Zone is thought to be the western end of the Pacific Ring of Fire, which marks out the subduction zones around the Pacific Ocean.Scientific study
Recent scientific work indicates that the earth's crust below the Taupo Volcanic Zone may be as little as 5 kilometres thick. Beneath this there appears to be a region of partially melted material that is the source of magma for the volcanoes in the zone. Because of this thin crust, all known volcanoes in the area are considered active, even if they have not erupted recently. The geological record indicates that some of the volcanoes in the area erupt infrequently but have large, violent and destructive eruptions when they do. There is also some possible rifting in the Taupo Volcanic Zone.
Volcanoes and thermal areas
See also List of volcanoes#In the Taupo Volcanic Zone.
- Whakaari/White Island
- Mayor Island/Tuhua
- Mount Mauao
- Mount Edgecumbe
- Tikitere/Hell's Gate
- Rotorua Caldera
- Whakarewarewa
- Okataina volcanic centre
- * Haroharo caldera
- * Mount Tarawera
- Waimangu
- Ben Lomond rhyolite dome (contains obsidian)
- Waiotapu
- Orakei Korako
- Wairakei
- Craters of the Moon
- Mount Tauhara
- Lake Taupo
- * Horomatangi Reefs
- Waihi (on the southwestern coast of Lake Taupo)
- Tokaanu
- Turangi
- Mount Tongariro
- * Mount Ngaruahoe
- Mount Ruapehu
Craters of The Moon
The Craters of the Moon thermal area in Wairakei Tourist Park sprang up in the 1950s, when the nearby power station lowered underground water levels. The 30 minute walk visits bubbling craters, mud pools and steam vents. You can also see a lot of interesting plants that have adapted to thrive in the hot, steamy conditions. Enjoy this fantastic geothermal area free of charge along well-formed pathways with elevated viewing platforms.Publications
- Physical volcanology and emplacement history of the Ben Lomond rhyolite lava flow, Taupo Volcanic Centre, New Zealand - New Zealand Journal of Geology and Geophysics, 1994, Vol. 37: 345-358 0028-8306/94/3703-0345 $2.50/0 © The Royal Society of New Zealand 1994 345 R. J. STEVENSON R. M. BRIGGS A. P. W. HODDER [web page]
External links
- [Further information on Taupo volcanics]
- [Tectonic plate information]
- [The Taupo Volcanic Zone with Māori Freehold Land (1995) - showing geothermal fields]
- [Earthquake risks]
- [pdf Measurement and implication of “effective” viscosity for rhyolite flow emplacement]
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.