Taupō Volcanic Zone

  (Redirected from Taupo Volcanic Zone)

The Taupō Volcanic Zone (TVZ) is a volcanic area in the North Island of New Zealand that has been active for the past two million years and is still highly active. Mount Ruapehu marks its south-western end and the zone runs north-eastward through the Taupō and Rotorua areas and offshore into the Bay of Plenty. It is part of the larger Central Volcanic Region that extends further westward through the western Bay of Plenty to the eastern side of the Coromandel Peninsula and has been active for four million years.[1] At Taupō the rift volcanic zone is widening east–west at the rate of about 8 mm per year while at Mount Ruapehu it is only 2–4 mm per year but this increases at the north eastern end at the Bay of Plenty coast to 10–15 mm per year.[2] It is named after Lake Taupō, the flooded caldera of the largest volcano in the zone, the Taupō Volcano and contains a large central volcanic plateau.

Volcano and lake/caldera locations in the Taupō Volcanic Zone. The distance between the town of Rotorua and the town of Taupō is 80 km. (White Island is not shown.)

ActivityEdit

There are numerous volcanic vents and geothermal fields in the zone, with Mount Ruapehu, Mount Ngauruhoe and White Island (Whakaari) erupting most frequently. Whakaari has been in continuous activity since 1826 if you count such as steaming fumaroles, but the same applies to say the Okataina volcanic centre.[3] The Taupō Volcanic Zone has produced in the last 350,000 years over 3,900 cubic kilometres (940 cu mi) material, more than anywhere else on Earth, from over 300 silicic eruptions, with 12 of these eruptions being caldera-forming.[4] The zone's largest eruption since the arrival of Europeans was that of Mount Tarawera in 1886, which killed over 100 people. Early Maori would also have been affected by the much larger Kaharoa eruption from Tarawera around 1315 CE.[5][6]

The last major eruption from Lake Taupō, the Hatepe eruption, occurred in 232 CE.[7] It is believed to have first emptied the lake, then followed that feat with a pyroclastic flow that covered about 20,000 km2 (7,700 sq mi) of land with volcanic ash. A total of 120 km3 (29 cu mi) of material is believed to have been ejected, and over 30 km3 (7.2 cu mi) of material is estimated to have been ejected in just a few minutes. The date of this activity was previously thought to be 186 AD as the ash expulsion was thought to be sufficiently large to turn the sky red over Rome and China (as documented in Hou Han Shu), but this has since been disproven.[7]

White Island had a major, edifice failure collapse of its volcano dated to 946 BCE ± 52 years. It has been suggested that this was the cause of the large tsunami that went up to 7 km inland (i.e. tens of meters tall) in the Bay of Plenty at about this time. Although significant tsunami's can be associated with volcanic eruptions, it is unknown if the cause was a relatively small eruption of Whakaari or another cause such as a large local earthquake[8]

Taupō erupted an estimated 1,170 km3 (280 cu mi) of material in its Oruanui eruption 25,600 years ago.[9] This was Earth's most recent eruption reaching VEI-8, the highest level on the Volcanic Explosivity Index.

The Rotorua caldera has been dormant longer, with its main eruption occurring about 240,000 years ago, although lava dome extrusion has occurred within the last 25,000 years.[10]

 
Satellite photo of the Lake Taupō caldera
 
In 1886, Mount Tarawera produced New Zealand's largest historic eruption since European colonisation
 
Lady Knox Geyser, Waiotapu geothermal area
 
Craters of the Moon geothermal area

Extent and geological contextEdit

The Taupō volcanic zone is approximately 350 kilometres (217 mi) long by 50 kilometres (31 mi) wide. Mount Ruapehu marks its southwestern end, while White Island is considered its northeastern limit.[11]

It forms a southern portion of the active Lau-Havre-Taupō back-arc basin, which lies behind the Kermadec-Tonga subduction zone.[12][13] Mayor Island and Mount Taranaki are recently active back arc volcanos on the New Zealand extension of this arc. Mayor Island / Tūhua is the most northernly shield volcano adjacent to the New Zealand coast and is believed to have been actice in the last 1000 years. [14] It is formed from rhyolite magma.[15] It has a quite complex eruptive history but only with one definite significant Plinian eruption.[14] Mount Taranaki is an andesite cone and the most recent of four Taranaki volcanos about 140 km (87 mi) west of the Taupo Volcanic Zone.[16]

Within the Taupō volcanic zone, intra-arc extension is expressed as normal faulting within a zone known as the Taupō Rift.[17] Volcanic activity continues to the north-northeast, along the line of the Taupō Volcanic Zone, through several undersea volcanoes in the South Kermadec Ridge Seamounts, then shifts eastward to the parallel volcanic arc of the Kermadec Islands and Tonga. Although the back-arc basin continues to propagate to the southwest, with the South Wanganui Basin forming an initial back-arc basin, volcanic activity has not yet begun in this region.[18]

South of Kaikoura the plate boundary changes to a transform boundary with oblique continental collision uplifting the Southern Alps / Kā Tiritiri o te Moana in the South Island. A subduction zone reappears southwest of Fiordland, at the southwestern corner of the South Island, although here the subduction is in the opposite direction. Solander Island is an extinct volcano associated with this subduction zone, and the only one that protrudes above the sea.

Scientific studyEdit

TectonicsEdit

Recent scientific work indicates that the Earth's crust below the Taupō Volcanic Zone may be as little as 16 kilometres thick. A film of magma 50 kilometres (30 mi) wide and 160 kilometres (100 mi) long lies 10 kilometres under the surface.[19][20] The geological record indicates that some of the volcanoes in the area erupt infrequently but have large, violent and destructive eruptions when they do.

Technically the zone is also known as the continental intraarc Taupō rift. This has had three active stages of faulting in the last 2 million years with the modern Taupō rift evolving in the last 25,000 years after the massive Oruanui eruption. The surrounding young Taupō Rift between 25,000 and 350,000 years and old Taupō Rift system are now located to the north of the other two being created between 350,000 and 2 million years.[2]

FaultsEdit

The multiple intra-rift faults are some of the most active in the country and some have the potential to create over magnitude 7 events. The fault structures are perhaps most well characterised related to the Ruapehu and Tongariro grabens. The recent deposits from major eruptions and lake features mean many potentially significant faults are uncharacterised, either completely (for example the 6.5 Mw 1987 Edgecumbe earthquake resulted in the mapping of the Edgecumbe fault for the first time) or frequency of events and their likely magnitude are not understood. It can not be assumed that just because the rate of expansion of the rift is greatest near the coast that this is where most significant tectonic earthquakes in terms of human risk will be. The Waihi Fault Zone south of Lake Taupō and associated with the Tongariro graben has a particular risk of inducing massive landslips which has caused significant loss of life and appears to be more active than many other faults in the zone.

VolcanismEdit

The north (Whakatane Graben – Bay of Plenty) part of the zone is predominantly formed from andesitic magma[21][22] and represented by the continuously active Whakaari / White Island andesitedacite stratovolcano. Although Strombolian activity has occurred the explosive eruptions are typically phreatic or phreatomagmatic.[23] The active emergent summit tops the larger, 16 kilometres (9.9 mi) × 18 kilometres (11 mi), submarine volcano with a total volume of 78 km3 (19 cu mi).[24][25][26][27]

The central part of the zone is composed of eight caldera centres the oldest of which is the Mangakino caldera which was active more than a million years ago (1.62–0.91 Ma).[21] This produced ignimbrite that 170 km (110 mi) away in Auckland is up to 9 m (30 ft) thick.[28] Other than the now buried Kapenga caldera there are five caldera centres, Rotorua, Ohakuri, Reporoa, Okataina and Taupo. These have resulted from massive infrequent eruptions of gaseous very viscous rhyolite magma which is rich in silicon, potassium, and sodium and created the ignimbrite sheets of the North Island Volcanic Plateau. Less gaseous rhyolite magma dome building effusive eruptions have built features such as the Horomatangi Reefs or Motutaiko Island in Lake Taupō or the lava dome of Mount Tarawera. This later as part of the Okataina caldera complex is the highest risk volcanic field in New Zealand to man. [29] Mount Tauhara adjacent to Lake Taupō is actually a dacitic dome [30] and so intermediate in composition between andesite and rhyolite but still more viscus than basalt which is absent from the zone.

The southern part of the zone contain classic volcanic cone structure formed from andesite magma in effusive eruptions that cool to form dark grey lava if gas-poor or scoria if gas-rich of this part of the zone. The tallest and central mountain in the North Island is Ruapehu, a 150 km3 (36 cu mi) andesite cone surrounded by a 150 km3 (36 cu mi) ring-plain.[31] This ring plain is formed from numerous volcanic deposits created by slope failure, eruptions, or lahars. Northwest of Ruapehu is Hauhungatahi, the oldest recorded volcano in the south of the plateau,[31] with to the north the two prominent volcanic mountains in the Tongariro volcanic centre being Tongariro and Ngāuruhoe which are part of a single composite stratovolcano.

Volcanoes, lakes and geothermal fieldsEdit

Map all coordinates using: OpenStreetMap 
Download coordinates as: KML

The following Volcanic Centers belong to the Taupō Volcanic Zone:

Rotorua, Okataina, Maroa, Taupō, Tongariro and Mangakino.[32][33]

 
Southwest side of Mount Tarawera, Mount Edgecumbe on the background.
 
Satellite view of the Lake Rotorua Caldera. Mount Tarawera is in the lower right corner.
 
Recent major volcanic features Lake Taupo showing relationship to recent volcanic vents in red and present active geothermal systems in light blue.
 
Composite satellite image of Mount Ruapehu

        Other important features of the TVZ include the Ngakuru and Ruapehu grabens.

NoteEdit

There is more recently a somewhat different classification:[21]

Panorama across Lake Taupō

See alsoEdit

ReferencesEdit

  1. ^ Cole, J.W.; Darby, D.J.; Stern, T.A. (1995). "Taupo Volcanic Zone and Central Volcanic Region: Backarc Structures of North Island, New Zealand". In Taylor, Brian (ed.). Backarc Basins: Tectonics and Magmatism. New York: Plenum. p. 3. ISBN 978-1-4615-1843-3.
  2. ^ a b Villimor, P.; Berryman, K. R.; Ellis, S. M.; Schreurs, G.; Wallace, L. M.; Leonard, G. S.; Langridge, R. M.; Ries, W. F. (2017-10-04). "Rapid Evolution of Subduction-Related Continental Intraarc Rifts: The Taupo Rift, New Zealand". Tectonics. 36 (10): 2250–2272. Bibcode:2017Tecto..36.2250V. doi:10.1002/2017TC004715. S2CID 56356050.
  3. ^ Waight, Tod E.; Troll, Valentin R.; Gamble, John A.; Price, Richard C.; Chadwick, Jane P. (2017-07-01). "Hf isotope evidence for variable slab input and crustal addition in basalts and andesites of the Taupo Volcanic Zone, New Zealand". Lithos. 284–285: 222–236. Bibcode:2017Litho.284..222W. doi:10.1016/j.lithos.2017.04.009. ISSN 0024-4937.
  4. ^ Kósik, Szabolcs; Nemeth, Karoly; Danisik, Martin; Procter, Jonathan; Schmitt, Axel; Friedrichs, Bjarne; Stewart, Robert (2021-01-19). "Shallow subaqueous to emergent intra-caldera silicic volcanism of the Motuoapa Peninsula, Taupo Volcanic Zone, New Zealand – New constraints from geologic mapping, sedimentology and zircon geochronology" (PDF). Journal of Volcanology and Geothermal Research. 411. doi:10.1016/j.jvolgeores.2021.107180.
  5. ^ Bonadonna, C.; Connor, C. B.; Houghton, B. F.; Connor, L.; Byrne, M.; Laing, A.; Hincks, T.K. (2005-03-15). "Probabilistic modeling of tephra dispersal: Hazard assessment of a multiphase rhyolitic eruption at Tarawera, New Zealand". Journal of Geophysical Research: Solid Earth. 110 (B3). Bibcode:2005JGRB..110.3203B. doi:10.1029/2003JB002896.
  6. ^ David, Lowe (2006). "Polynesian settlement and impacts of volcanism on early Maori society" (PDF). In Lowe, D.J. (ed.). Guidebook for 'Land and Lakes' field trip, New Zealand Society of Soil Science Biennial Conference, Rotorua, held in 27–30 November 2006. Lincoln: New Zealand Society of Soil Science. pp. 50–55.
  7. ^ a b Illsley-Kemp, Finnigan; Barker, Simon J.; Wilson, Colin J. N.; Chamberlain, Calum J.; Hreinsdóttir, Sigrún; Ellis, Susan; Hamling, Ian J.; Savage, Martha K.; Mestel, Eleanor R. H.; Wadsworth, Fabian B. (2021-06-01). "Volcanic Unrest at Taupō Volcano in 2019: Causes, Mechanisms and Implications". Geochemistry, Geophysics, Geosystems. 22 (6): 1–27. Bibcode:2021GGG....2209803I. doi:10.1029/2021GC009803.
  8. ^ de Lange, Willem; Moon, Vicki (2016). Volcanic generation of tsunamis: Two New Zealand palaeo-events in Submarine Mass Movements and their Consequences (PDF). 56.{{cite book}}: CS1 maint: location (link)
  9. ^ Dunbar, Nelia W.; Iverson, Nels A.; Van Eaton, Alexa R.; Sigl, Michael; Alloway, Brent V.; Kurbatov, Andrei V.; Mastin, Larry G.; McConnell, Joseph R.; Wilson, Colin J. N. (2017-09-25). "New Zealand supereruption provides time marker for the Last Glacial Maximum in Antarctica". Scientific Reports. 7 (1): 12238. Bibcode:2017NatSR...712238D. doi:10.1038/s41598-017-11758-0. PMC 5613013. PMID 28947829.
  10. ^ "Rotorua". Global Volcanism Program. Smithsonian Institution. Retrieved 2010-08-31.
  11. ^ Gamble, J. A.; Wright, I. C.; Baker, J. A. (1993). "Seafloor geology and petrology in the oceanic to continental transition zone of the Kermadec-Havre-Taupo Volcanic Zone arc system, New Zealand". New Zealand Journal of Geology and Geophysics. 36 (4): 417–435. doi:10.1080/00288306.1993.9514588. Archived from the original on 2008-11-22.
  12. ^ Caratori Tontini, F.; Bassett, D.; de Ronde, C. E. J.; Timm, C.; Wysoczanski, R. (2019). "Early evolution of a young back-arc basin in the Havre Trough" (PDF). Nature Geoscience. 12 (10): 856–862. Bibcode:2019NatGe..12..856C. doi:10.1038/s41561-019-0439-y. S2CID 202580942.
  13. ^ Parson, L. M.; Wright, I. C. (1996). "The Lau-Havre-Taupo back-arc basin: A southward-propagating, multi-stage evolution from rifting to spreading". Tectonophysics. 263 (1–4): 1–22. Bibcode:1996Tectp.263....1P. doi:10.1016/S0040-1951(96)00029-7.
  14. ^ a b Houghton, B.F.; Wilson, J. N. C; Weaver, S.D.; Lanphere, M.A.; Barclay, J (1995). "Mayor Island Geology". Volcanic Hazards at Mayor Island. [Palmerston North, NZ]: Ministry of Civil Defence. Volcanic Hazards Information Series 6.: 1–23.
  15. ^ Houghton, Bruce F.; Weaver, S.D.; Wilson, J. N.; Lanphere, M.A. (1992). "Evolution of a quaternary peralkaline volcano: Mayor Island, New Zealand". Journal of Volcanology and Geothermal Research. 51 (3): 217–236. Bibcode:1992JVGR...51..217H. doi:10.1016/0377-0273(92)90124-V.
  16. ^ Price, R. C.; Stewart, R. B.; Woodhead, J. D.; Smith, I. E. M. (1999). "Petrogenesis of High-K Arc Magmas: Evidence from Egmont Volcano, North Island, New Zealand". Journal of Petrology. 40 (1): 167–197. doi:10.1093/petroj/40.1.167.
  17. ^ Holden, Lucas; Wallace, L.; Beavan, J.; Fournier, Nico; Cas, Raymond; Ailleres, Laurent; Silcock, David. (2015-07-28). "Contemporary ground deformation in the Taupo Rift and Okataina Volcanic Centre from 1998 to 2011, measured using GPS". Geophysical Journal International. 202 (3): 2082–2105. doi:10.1093/gji/ggv243.
  18. ^ Villamor, P.; Berryman, K. R. (2006). "Evolution of the southern termination of the Taupo Rift, New Zealand". New Zealand Journal of Geology and Geophysics. 49: 23–37. doi:10.1080/00288306.2006.9515145.
  19. ^ Easton, Paul (15 September 2007). "Central North Island sitting on magma film". The Dominion Post. Retrieved 16 March 2008.
  20. ^ Heise, W.; Bibby, H.M.; Caldwell, T.G. (2007). "Imaging magmatic Processes in the Taupo Volcanic Zone (New Zealand) with Magnetotellurics" (PDF). Geophysical Research Abstracts. 9. 01311.
  21. ^ a b c Cole, J. W.; Spinks, K. D. (2009). "Caldera volcanism and rift structure in the Taupo Volcanic Zone, New Zealand". Special Publications. London: Geological Society. 327 (1): 9–29. Bibcode:2009GSLSP.327....9C. doi:10.1144/SP327.2. S2CID 131562598.
  22. ^ Hiess, J; Cole, JW; Spinks, KD (2007). High-Alumina Basalts of the Taupo Volcanic Zone, New Zealand: Influence of the Crust and Crustal Structure (PDF). p. 36. Part of a BSc Project by Hiess, J. (University of Canterbury).{{cite book}}: CS1 maint: postscript (link)
  23. ^ Houghton, B. F.; Nairn, I. A. (1 December 1991). "The 1976–1982 Strombolian and phreatomagmatic eruptions of White Island, New Zealand: eruptive and depositional mechanisms at a 'wet' volcano". Bulletin of Volcanology. 54 (1): 25–49. Bibcode:1991BVol...54...25H. doi:10.1007/BF00278204. S2CID 128897275.
  24. ^ Cole, J.W., Thordarson, T. and Burt, R.M., 2000. Magma origin and evolution of White Island (Whakaari) volcano, Bay of plenty, New Zealand. Journal of Petrology, 41(6), pp.867–895.
  25. ^ Moon, V., Bradshaw, J. and de Lange, W., 2009. Geomorphic development of White Island Volcano based on slope stability modelling. Engineering Geology, 104(1–2), pp.16–30.
  26. ^ Jimenez, C., 2015. Magmatic-hydrothermal system at White Island volcano, North Island, New Zealand. in M. Calder, ed., pp. 35–46, JCU SEG Student Chapter New Zealand, North Island Field Trip 2015 Guide Book. Queensland, Australia: James Cook University SEG Student Chapter, Society of Economic Geologists, Inc.
  27. ^ Duncan, A.R., 1970. The petrology and petrochemistry of andesite volcanoes in Eastern Bay of Plenty, New Zealand. Unpublished Ph.D. thesis, Victoria University of Wellington, New Zealand. pp.362
  28. ^ "GUIDEBOOK FOR LAND AND LAKES FIELD TRIP". New Zealand Society of Soil Science. 2006-11-28.
  29. ^ Doherty, Angela Louise (2009). "Blue‐sky eruptions, do they exist? Implications for monitoring New Zealand's volcanoes" (PDF). University of Canterbury. Retrieved 2022-06-07.
  30. ^ Volcanic Hazards Working Group of the Civil Defence Scientific Advisory Committee, which includes scientists from the Institute of Geological and Nuclear Sciences and the Universities, Number seven "Taupo Volcanic Centre" Archived 2006-10-06 at the Wayback Machine
  31. ^ a b Leonard, Graham S.; Cole, Rosie P.; Christenson, Bruce W.; Conway, Chris E.; Cronin, Shane J.; Gamble, John A.; Hurst, Tony; Kennedy, Ben M.; Miller, Craig A.; Procter, Jonathan N.; Pure, Leo R.; Townsend, JDougal B.; White, James D. L.; Wilson, Colin J. N. (2021-05-02). "Ruapehu and Tongariro stratovolcanoes: a review of current understanding". New Zealand Journal of Geology and Geophysics. 64 (2–3): 389–420. doi:10.1080/00288306.2021.1909080. S2CID 235502116.
  32. ^ Cole, J.W. (1990). "Structural control and origin of volcanism in the Taupo volcanic zone, New Zealand". Bulletin of Volcanology. 52 (6): 445–459. Bibcode:1990BVol...52..445C. doi:10.1007/BF00268925. S2CID 129091056.
  33. ^ "New Zealand".
  34. ^ a b c d e f g http://www.volcano.si.edu/world/largeeruptions.cfm[bare URL]
  35. ^ Newhall, Christopher G.; Dzurisin, Daniel (1988). "Historical unrest at large calderas of the world". USGS Bulletin. 1855: 1108. Citing Scott, B.J. (1986). Gregory, J.G.; Watters, W.A. (eds.). "Volcanic hazards assessment in New Zealand: Monitoring at Okataina Volcanic Centre". New Zealand Geol. Surv. Rec. 10: 49–54.
  36. ^ Okataina Volcanic Center, New Zealand
  37. ^ Nairn, I.A. (2002). Geology of the Okatania Volcanic Centre. Geological Map 25. Institute of Geological and Nuclear Sciences. p. 156.
  38. ^ a b Hodgson, K. A.; Nairn, I. A. (August 2004). "The Sedimentation and Drainage History of Haroharo Caldera and The Tarawera River System, Taupo Volcanic Zone, New Zealand" (PDF). Operations Publication 2004/03. Environment Bay of Plenty: 7. ISSN 1176-5550. Archived from the original (PDF) on 2010-05-22.
  39. ^ Krippner, Stephen J. P.; Briggs, Roger M.; Wilson, Colin J. N.; Cole, James W. (1998). "Petrography and geochemistry of lithic fragments in ignimbrites from the Mangakino Volcanic Centre: implications for the composition of the subvolcanic crust in western Taupo Volcanic Zone, New Zealand". New Zealand Journal of Geology and Geophysics. 41 (2): 187–199. doi:10.1080/00288306.1998.9514803.
  40. ^ Gravley, D. M.; Wilson, C. J. N.; Rosenberg, M. D.; Leonard, G. S. (2006). "The nature and age of Ohakuri Formation and Ohakuri Group rocks in surface exposures and geothermal drillhole sequences in the central Taupo Volcanic Zone, New Zealand". New Zealand Journal of Geology and Geophysics. 49 (3): 305–308. doi:10.1080/00288306.2006.9515169. S2CID 129012659.

External linksEdit