Matata Fault

Active fault in New Zealand

38°00′00″S 176°40′16″E / 38.0°S 176.671°E / -38.0; 176.671CountryNew ZealandRegionBay of Plenty RegionCharacteristicsDisplacement1 mm (0.039 in)/year^[2]TectonicsPlateIndo-AustralianStatusActive with M_w 7.0 potential,^[3] recurrence is <=2,000 years^[1]TypeNormal fault^[1]AgeHolocene ~1–0 Ma^[4]

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Volcanic arc/belt Taupō Volcanic ZoneNew Zealand geology database (includes faults)

The Matata Fault zone is a seismically active area in the Bay of Plenty Region of the central North Island of New Zealand with potential to rupture as part of an M_w 7.0 event.^[3]

Geology

The Matata Fault zone is the northwestern wall fault of the Whakatāne Graben and extends from the coast near Matatā to where the boundary of the modern Taupō Rift changes direction to a mainly SSE-dipping fault trace of the Manawahe Fault.^[3] At this southern end of the fault there is an area of Manawahe dacite that has been dated to 425,000 ± 27,000 years ago.^[2] There has been considerable uplift of Castlecliffian (mid Quaternary) marine sediments at a rate of 1 mm (0.039 in)/year to more than 300 m (980 ft) above sea level.^[2] An earthquake swam that commenced in 2005 at the northern end of the Matata Fault zone progressed off shore and lasted until 2009.^[5] At the coast there was an area of transition of a few miles with lower current seismic activity to defined off shore faults.^[5] These earthquakes were also associated with about 400 km² (150 sq mi) of area that has risen by up to 40 cm (16 in) since the 1950s.^[6] The increase of height over this area is not thought to be consistent with a pure tectonic origin but would be consistent with inflation from the accumulation of magma at a depth of about 9.5 km (5.9 mi).^[6] This magma body was later interpreted as a newly stalled sill under the northern Matata Fault.^[7]

Risks

During the period 2005 to 2009 an earthquake swarm occurred near Matatā with many low magnitude earthquakes and one of M_w 4.7 .^[6] A potentially whole fault rupture could be up to M_w 7.0 if the fault ruptured at the same time as the shorter Manawahe Fault which is a continuation.^[3] Volcanic eruption risk is not negligible given the past eruption of Manawahe Massif dacite/andesite and the coupling of the Manawahe Fault with other eruptions.^[3]

References

^ ^a ^b ^c "GNS:New Zealand Active Faults Database". Retrieved 7 April 2023.
^ ^a ^b ^c Nairn, IA; Beanland, S (1989). "Geological setting of the 1987 Edgecumbe earthquake, New Zealand". New Zealand Journal of Geology and Geophysics. 32 (1): 1–3. Bibcode:1989NZJGG..32....1N. doi:10.1080/00288306.1989.10421383.
^ ^a ^b ^c ^d ^e Villamor, P.; Litchfield, N.J.; Gomez, D.; Martin, F.; Alloway, B.; Berryman, K.; Clark, K.; Ries, W.; Howell, A.; Ansell, B. (2022). "Fault ruptures triggered by large rhyolitic eruptions at the boundary between tectonic and magmatic rift segments: the Manawahe Fault, Taupo Rift, New Zealand". Journal of Volcanology and Geothermal Research. 427: 107478. Bibcode:2022JVGR..42707478V. doi:10.1016/j.jvolgeores.2022.107478. hdl:2292/59828. S2CID 246258923.
^ Taylor, Susanna K. A Long Timescale High-Resolution Fault Activity History of the Whakatane Graben, Bay of Plenty, New Zealand (PhD thesis Graduate School of the Southampton Oceanography Centre) (PDF) (Thesis). Retrieved 4 April 2023.
^ ^a ^b Mouslopoulou, Vasiliki; Hristopulos, Dionissios T. (2011). "Patterns of tectonic fault interactions captured through geostatistical analysis of microearthquakes". Seismology. 116 (B7). Bibcode:2011JGRB..116.7305M. doi:10.1029/2010JB007804.
^ ^a ^b ^c Hamling, Ian J.; Hreinsdóttir, Sigrun; Bannister, Stephen; Palmer, Neville (2016). "Off-axis magmatism along a subaerial back-arc rift: Observations from the Taupo Volcanic Zone, New Zealand". Science Advances. 2 (6): e1600288. Bibcode:2016SciA....2E0288H. doi:10.1126/sciadv.1600288. PMC 4928910. PMID 27386580.
^ Gase, Andrew C.; Van Avendonk, Harm J. A.; Bangs, Nathan L.; Luckie, Thomas W.; Barker, Daniel H. N.; Henrys, Stuart A.; Bassett, Dan; Okaya, David A.; Jacobs, Katrina M.; Kodaira, Shuichi (2019). "Seismic Evidence of Magmatic Rifting in the Offshore Taupo Volcanic Zone, New Zealand". Geophysical Research Letters. 46 (22): 12949–12957. Bibcode:2019GeoRL..4612949G. doi:10.1029/2019GL085269. S2CID 212798500.

Seismic faults of New Zealand

North Island

North Island Fault System	Kaweka Fault Mohaka Fault Patoka Fault Ruahine Fault Rukumoana Fault Te Whaiti Fault Waimana Fault Waiohau Fault Waiotahi Fault Wairarapa Fault Wellington Fault Wheao Fault Whakatane Fault
Taupō Volcanic Zone (Taupo Rift)	Aratiatia Fault Edgecumbe Fault Matata Fault Manawahe Fault Haukari West Whangamata Fault Horohoro Fault Kaiapo Fault Karioi Fault Ngapouri-Rotomahana Fault National Park Fault Ohakune Fault Orakonui Fault Paeroa Fault Poutu Fault Zone Puketarata Fault Rangipo Fault Raurimu Fault Taupō Fault Belt Thorpe - Poplar Fault Upper Waikato Stream Fault Wahianoa Fault Waihi Fault Zone Waipuna Fault
Hauraki Rift	Firth of Thames Fault Hauraki Fault Kerepehi Fault
Auckland regional faults	Wairoa North Fault

South Island

Alpine Fault
Marlborough fault system	Awatere Fault Clarence Fault Elliott Fault Hope Fault Kekerengu Fault Wairau Fault
Canterbury fault system	Hundalee Fault Christchurch Fault Greendale Fault Port Hills Fault Ostler Fault Zone
Otago fault system	Akatore Fault Green Island Fault Kaikorai Fault Titri Fault Hyde Fault