The Hikurangi Plateau is an oceanic plateau in the South Pacific Ocean east of the North Island of New Zealand. It is part of a large igneous province (LIP) together with Manihiki and Ontong Java, now located 3,000 km (1,900 mi) and 3,500 km (2,200 mi) north of Hikurangi respectively.[1]Mount Hikurangi, in Māori mythology the first part of the North Island to emerge from the ocean, gave its name to the plateau.
One of the major divisions of Zealandia, the Hikurangi Plateau (top right) drifted south and collided with parts of the mostly submerged continent.
The Hikurangi Plateau covers approximately 400,000 km2 (150,000 sq mi) and reaches 2,500–3,000 m (8,200–9,800 ft) below sea level.[2]
Hikurangi Plateau is cut by the Hikurangi Channel, a 2000 km abyssal channel that starts at Kaikoura and runs along the Hikurangi Trench as far as the Māhia Peninsula before crossing the plateau and ending in the South-west Pacific abyssal plain.[3]
Tectonic evolution
Two models have been proposed for the formation of Hikurangi. It can be derived from the mantle plume that caused the break-up of Gondwana and the separation of Zealandia from Antarctica 107 Ma. Alternatively, it could have formed together with other Pacific plateaux around 120 Ma as part of the Ontong Java-Manihiki-Hikurangi mega-plateau, in which case Hikurangi must have drifted thousands of kilometres during the Cretaceous silent period (84–121 Ma) before colliding with Gondwana.[1]
A 2010 study of isotopic data supported the mega-plateau or "Greater Ontong Java Event" model. The study added several basins as remains of this LIP event, including the north-west part of the Central Pacific, Nauru, East Mariana, and Lyra basins — submarine volcanism that must have covered 1% of Earth's surface and had a dramatic impact on life on Earth. There are, nevertheless, traces in seamounts on Hikurangi of a second Late Cretaceous magmatic event contemporaneous with volcanism on New Zealand and associated with the final break-up of Gondwana.[1]
The Hikurangi Plateau has been partly subducted under the Chatham Rise, probably during the Cretaceous, and probably resulting in a slab more than 150 km (93 mi) long. The western margin of the plateau is actively subducting under the North Island of New Zealand to a depth of 65 km (40 mi). With these missing portions of the plateau added to it, the Hikurangi Plateau originally must have covered 800,000 km2 (310,000 sq mi), an area similar to that of the Manihiki Plateau 3,000 km (1,900 mi) to the north.[2]
The Hikurangi Plateau first subducted beneath New Zealand around 100 Ma during the Gondwana collision and it is currently subducting a second time as part of the convergence between the Pacific and Australian plates. These subducted parts are reaching 37–140 km (23–87 mi) into the mantle beneath the North Island and northern South Island.[4] The extent of the Hikurangi Plateau slab suggests that it has played a significant role in the geology of New Zealand during the past 100 Ma. The Southern Alps in central South Island are being uplifted along the plate boundary there, a fault zone which parallels the western edge of the slab of the Hikurangi Plateau.[5]
The Australian and Pacific plates converge obliquely in the Tonga-Kermadec-Hikurangi subduction zone. The Hikurangi Plateau alters this subduction beneath North Island, at the Hikurangi subduction zone, where the buoyancy of the slab has resulted in the exposure of a forearc and hence earthquakes such as the 7.8 Mw1931 Hawke's Bay earthquake.[6]
Henrys, S.; Reyners, M.; Pecher, I.; Bannister, S.; Nishimura, Y.; Maslen, G. (2006). "Kinking of the subducting slab by escalator normal faulting beneath the North Island of New Zealand". Geology. 34 (9): 777–780. Bibcode:2006Geo....34..777H. doi:10.1130/G22594.1. Retrieved 11 December 2016.
Hoernle, K.; Hauff, F.; van den Bogaard, P.; Werner, R.; Mortimer, N.; Geldmacher, J.; Garbe-Schönberg, D.; Davy, B. (2010). "Age and geochemistry of volcanic rocks from the Hikurangi and Manihiki oceanic plateaus" (PDF). Geochimica et Cosmochimica Acta. 74 (24): 7196–7219. Bibcode:2010GeCoA..74.7196H. doi:10.1016/j.gca.2010.09.030. Retrieved 11 December 2016.
Lewis, Keith; Nodder, Scott D.; Carter, Lionel (2009). "Sea floor geology – Hikurangi Plateau". Te Ara – the Encyclopedia of New Zealand. Retrieved 11 December 2016.
Reyners, M.; Eberhart-Phillips, D.; Bannister, S. (2011). "Tracking repeated subduction of the Hikurangi Plateau beneath New Zealand". Earth and Planetary Science Letters. 311 (1): 165–171. Bibcode:2011E&PSL.311..165R. doi:10.1016/j.epsl.2011.09.011. Retrieved 11 December 2016.
hikurangi, plateau, oceanic, plateau, south, pacific, ocean, east, north, island, zealand, part, large, igneous, province, together, with, manihiki, ontong, java, located, north, hikurangi, respectively, mount, hikurangi, māori, mythology, first, part, north, . The Hikurangi Plateau is an oceanic plateau in the South Pacific Ocean east of the North Island of New Zealand It is part of a large igneous province LIP together with Manihiki and Ontong Java now located 3 000 km 1 900 mi and 3 500 km 2 200 mi north of Hikurangi respectively 1 Mount Hikurangi in Maori mythology the first part of the North Island to emerge from the ocean gave its name to the plateau One of the major divisions of Zealandia the Hikurangi Plateau top right drifted south and collided with parts of the mostly submerged continent Contents 1 Geological setting 2 Tectonic evolution 3 See also 4 References 4 1 Notes 4 2 SourcesGeological setting EditThe Hikurangi Plateau covers approximately 400 000 km2 150 000 sq mi and reaches 2 500 3 000 m 8 200 9 800 ft below sea level 2 Hikurangi Plateau is cut by the Hikurangi Channel a 2000 km abyssal channel that starts at Kaikoura and runs along the Hikurangi Trench as far as the Mahia Peninsula before crossing the plateau and ending in the South west Pacific abyssal plain 3 Tectonic evolution EditTwo models have been proposed for the formation of Hikurangi It can be derived from the mantle plume that caused the break up of Gondwana and the separation of Zealandia from Antarctica 107 Ma Alternatively it could have formed together with other Pacific plateaux around 120 Ma as part of the Ontong Java Manihiki Hikurangi mega plateau in which case Hikurangi must have drifted thousands of kilometres during the Cretaceous silent period 84 121 Ma before colliding with Gondwana 1 A 2010 study of isotopic data supported the mega plateau or Greater Ontong Java Event model The study added several basins as remains of this LIP event including the north west part of the Central Pacific Nauru East Mariana and Lyra basins submarine volcanism that must have covered 1 of Earth s surface and had a dramatic impact on life on Earth There are nevertheless traces in seamounts on Hikurangi of a second Late Cretaceous magmatic event contemporaneous with volcanism on New Zealand and associated with the final break up of Gondwana 1 The Hikurangi Plateau has been partly subducted under the Chatham Rise probably during the Cretaceous and probably resulting in a slab more than 150 km 93 mi long The western margin of the plateau is actively subducting under the North Island of New Zealand to a depth of 65 km 40 mi With these missing portions of the plateau added to it the Hikurangi Plateau originally must have covered 800 000 km2 310 000 sq mi an area similar to that of the Manihiki Plateau 3 000 km 1 900 mi to the north 2 The Hikurangi Plateau first subducted beneath New Zealand around 100 Ma during the Gondwana collision and it is currently subducting a second time as part of the convergence between the Pacific and Australian plates These subducted parts are reaching 37 140 km 23 87 mi into the mantle beneath the North Island and northern South Island 4 The extent of the Hikurangi Plateau slab suggests that it has played a significant role in the geology of New Zealand during the past 100 Ma The Southern Alps in central South Island are being uplifted along the plate boundary there a fault zone which parallels the western edge of the slab of the Hikurangi Plateau 5 The Australian and Pacific plates converge obliquely in the Tonga Kermadec Hikurangi subduction zone The Hikurangi Plateau alters this subduction beneath North Island at the Hikurangi subduction zone where the buoyancy of the slab has resulted in the exposure of a forearc and hence earthquakes such as the 7 8 Mw 1931 Hawke s Bay earthquake 6 See also EditCampbell Plateau Large low shear velocity provinces Tonga Kermadec RidgeReferences EditNotes Edit a b c Hoernle et al 2010 Introduction pp 7196 7198 a b Hoernle et al 2010 Geological overview morphology and rock types pp 7198 7200 Lewis Nodder amp Carter 2009 Reyners Eberhart Phillips amp Bannister 2011 Abstract Reyners Eberhart Phillips amp Bannister 2011 Discussion pp 170 171 Henrys et al 2006 Hikurangi subduction zone p 777 Sources Edit Henrys S Reyners M Pecher I Bannister S Nishimura Y Maslen G 2006 Kinking of the subducting slab by escalator normal faulting beneath the North Island of New Zealand Geology 34 9 777 780 Bibcode 2006Geo 34 777H doi 10 1130 G22594 1 Retrieved 11 December 2016 Hoernle K Hauff F van den Bogaard P Werner R Mortimer N Geldmacher J Garbe Schonberg D Davy B 2010 Age and geochemistry of volcanic rocks from the Hikurangi and Manihiki oceanic plateaus PDF Geochimica et Cosmochimica Acta 74 24 7196 7219 Bibcode 2010GeCoA 74 7196H doi 10 1016 j gca 2010 09 030 Retrieved 11 December 2016 Lewis Keith Nodder Scott D Carter Lionel 2009 Sea floor geology Hikurangi Plateau Te Ara the Encyclopedia of New Zealand Retrieved 11 December 2016 Reyners M Eberhart Phillips D Bannister S 2011 Tracking repeated subduction of the Hikurangi Plateau beneath New Zealand Earth and Planetary Science Letters 311 1 165 171 Bibcode 2011E amp PSL 311 165R doi 10 1016 j epsl 2011 09 011 Retrieved 11 December 2016 Coordinates 40 S 179 E 40 S 179 E 40 179 Retrieved from https en wikipedia org w index php title Hikurangi Plateau amp oldid 1089520309, wikipedia, wiki, book, books, library,
