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32-515: The Taupō Fault Belt contains many almost parallel active faults, and is located in the Taupō Rift of the central North Island of New Zealand geographically between Lake Taupō and the lakes of Rotorua , Tarawera , Rotomahana and Rerewhakaaitu . The potential active fault density is very high, with only 0.1 to 1 km (0.062 to 0.621 mi) separating the north-east to south-west orientated normal fault strands on detailed mapping of part of

64-651: A triple junction , although there are three, the East African Rift , Rio Grande rift and the Baikal Rift Zone , which are currently active, as well as a fourth which may be, the West Antarctic Rift System . In these instances, not only the crust but entire tectonic plates are in the process of breaking apart forming new plates. If they continue, continental rifts will eventually become oceanic rifts. Other rift valleys are

96-580: A Whakaipo fault zone. Also active in the north of the southern Taupō Fault Belt are the Puketarata, Orakeikorako, Lake Ohakuri, Tuahu and the Orakonui Faults. Detailed mapping, supplemented by deep ground trenching, of a portion of the southern Taupō Fault Belt prior to construction of a geothermal power station not only showed how inaccurate the inferred active fault tracings in this area are, with under counting potential active fault strands by

128-515: A factor of perhaps two, it also caused the relocation of the power station. There are discontinuities in the definable faults of the modern Taupō Rift imposed by its caldera's, with the Taupō Volcano and the Ōkataina Volcanic Centre at the southern and northern end of the Taupō Fault Belt respectively defining the limits of its predominant tectonic activity. Tectonic activity predominates in

160-492: A gravity anomaly, is now located more to the north being created between 350,000 and 2 million years and is about 70 kilometres (43 mi) wide. Consensus does not yet exist with regard to the cause of the Taupō Rift's extension or the exceptional volcanic productivity of the associated Taupō Volcanic Zone . Its geology and landforms are of worldwide interest, and it contains multiple significant faults and volcanoes, with some of

192-594: A relatively short geological timeframe. In the Bay of Plenty region the current active faults of the old Taupō Rift can align with those of the modern Taupō Rift. This was illustrated by the Edgecumbe Fault and the off sea White Island Fault in the Whakatāne Graben of the rift. The parallel Tauranga Fault Zone to the north represents a now mainly inactive old Taupō Rift margin. Further south, where more of

224-413: A rift which results from a leftward discontinuity in the left lateral-moving Dead Sea Transform fault. Where a fault breaks into two strands, or two faults run close to each other, crustal extension may also occur between them, as a result of differences in their motions. Both types of fault-caused extension commonly occur on a small scale, producing such features as sag ponds or landslides . Many of

256-568: Is a prominent example. Charon's Nostromo Chasma is the first confirmed in the Pluto system, however large chasms up to 950 km wide observed on Charon have also been tentatively interpreted by some as giant rifts, and similar formations have also been noted on Pluto. A recent study suggests a complex system of ancient lunar rift valleys, including Vallis Rheita and Vallis Alpes . The Uranus system also has prominent examples, with large 'chasma' believed to be giant rift valley systems, most notably

288-460: Is believed by planetary geologists to be a large rift system. Some features of Venus, most notably, the 4,000 km Devana Chasma and a part of the western Eistla, and possibly also Alta and Bell Regio have been interpreted by some planetary geologists as rift valleys. Some natural satellites also have prominent rift valleys. The 2,000 km long Ithaca Chasma on Tethys in the Saturn system

320-551: Is driven by oral tradition reports of hundreds dying in a relatively recent landslip on the Waihi Fault Zone south of Lake Taupō it may not be true. Certainly in the context that the Taupō Volcano has been responsible for the largest eruption of the last 30,000 years being the Oruanui eruption , and the more recent smaller 232 ± 10 CE Hatepe eruption but both eruptions occurred before human settlement,

352-616: Is preserved. The modern Taupō Volcanic Zone started forming 61,000 years ago but the modern Taupō Rift appears to only have intra-rift fault activity after the immensely disruptive Oruanui eruption . Earthquake activity in the Taupo Rift exhibits the entire spectrum of behaviour ranging from large, ground rupturing events to swarm activity comprising thousands of small events. In the time since Māori settlement these larger earthquakes can be speculated to have resulted in more indirect loss of life than volcanic activity, although as this

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384-509: Is tectonic. The rift is in that part of the continental Australian Plate associated with the largely underwater Zealandia continental tectonic plate region. The rate of spread of the rift varies from effectively zero, at its southern inland end where the South Wanganui Basin is forming an initial back-arc basin, and volcanic activity has not yet begun, to in the Bay of Plenty as much as 19 mm (0.75 in)/yr. To

416-549: Is the seismically active rift valley containing the Taupō Volcanic Zone , central North Island of New Zealand . The Taupō Rift ( Taupo Rift ) is a 300 km (190 mi) intra-arc continental rift resulting from an oblique convergence in the Hikurangi subduction zone . The present young, modern Taupō Rift is defined by events between 25,000 and 350,000 years and the old Taupō Rift system, which can be defined by

448-523: The Trans-Mexican Volcanic Belt result from a different tectonic process from the more studied intracontinental (intraplate) rifts it has been shown that the Taupō Rift displays all of the three modes of evolution. These are narrowing, lateral migration, and along-strike propagation, as found with intracontinental rifts. The Taupo Rift is widening much faster that other continental intraarc rifts, which might drive this evolution during

480-876: The Ngakuru Graben between it and the Whirinaki Fault. Within the 14 km (8.7 mi) wide Ngakuru Graben are also to the west the Maleme Fault (Zone), which as a zone also contains the Mangaete/Lakeside Fault and to the east the Hossack Road Fault and the Te Weta Fault. The tectonic activity is driven by the ground subsiding at a rate of 0.3–0.4 cm/year (0.12–0.16 in/year) since 61,000 years ago with largely orthogonal rifting associated with subduction and

512-455: The active extension by 8 mm (0.31 in)/year ± 2 mm (0.079 in). This is similar to the case in the northern Taupō Fault Belt and modern earthquake swarm analysis allows many of these faults to be assigned to distinct zones. Accordingly there is a Kaiapo fault zone just to the west of the town of Taupō and the Ngangiho fault zone just to the east of Kinloch with between them

544-712: The belt. The Waikato River bisects the western region of the belt. The northern Taupō Fault Belt is in the area also referred to as either, the Paeroa Graben or the Kapenga Graben, between the Horohoro Fault and the Paeroa Fault . Aligned with the orientation of the modern Taupō Rift are multiple north-north-east trending normal faults. These include the Ngakuru Fault to the east with

576-661: The clockwise rotation of the northern North Island allowing the rift to open. The southern Taupō Fault Belt is bounded to the west by a zone of faults that include the Thorpe - Poplar Fault in the north and the Whangamata fault zone . Between these faults and the eastern edge of the belt bounded by the Aratiatia fault zone to the north and the Rotokawa Fault to the south there are many intra-rift faults associated with

608-677: The largest freshwater lake by area, lies in the ancient and dormant Midcontinent Rift . The largest subglacial lake, Lake Vostok , may also lie in an ancient rift valley. Lake Nipissing and Lake Timiskaming in Ontario and Quebec , Canada lie inside a rift valley called the Ottawa-Bonnechere Graben . Þingvallavatn , Iceland's largest natural lake, is also an example of a rift lake. Rift valleys are also known to occur on other terrestrial planets and natural satellites. The 4,000 km long Valles Marineris on Mars

640-436: The north but in the south increase to up to 10 kilometres (6.2 mi) separation. There are breaks in the intra-rift fault systems in the recently active central rhyolitic caldera segments at the Taupō Volcano and Ōkataina Caldera. In the later case, the strike of the basaltic dyke of the 1886 eruption of Mount Tarawera follows that of faults to the south and north, confirming other hints that orientation of volcanism

672-477: The north east it is related tectonically to the Havre Trough off the continental shelf which is also an active rift structure. The spread of the rift is associated with the basement graywacke rocks subsiding between the rift walls, so creating grabens infilled with volcanic deposits, sometimes from much higher volcanic mountains than the rift walls. Between 2016 and 2020 there was low volcanic activity in

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704-529: The old Taupō Rift faults appear to be inactive, the active and very complex Taupō Fault Belt is orientated north-north-east. This is trending with the modern Taupō Rift alignment, which is not always quite parallel with the old rift alignment. Beyond Lake Taupō to the south, there is a relatively narrow rifting segment in the Tongariro graben which considerably widens at the Ruapehu graben. South of Ruapehu

736-509: The present rift also south of Lake Taupō until the active andesitic volcanoes of the North Island Volcanic Plateau are reached or from the Ōkataina Caldera north through the Whakatāne Graben to the active andesitic volcano of Whakaari / White Island . The recently active vents in the main volcanoes are not aligned with currently active faults in the Taupō Fault Belt but there are interactions and for example there

768-559: The relative risk of earthquakes versus volcanoes depends upon time scale considered. Rift valley The most extensive rift valley is located along the crest of the mid-ocean ridge system and is the result of sea floor spreading . Examples of this type of rift include the Mid-Atlantic Ridge and the East Pacific Rise . Many existing continental rift valleys are the result of a failed arm ( aulacogen ) of

800-475: The result of bends or discontinuities in horizontally-moving (strike-slip) faults. When these bends or discontinuities are in the same direction as the relative motions along the fault, extension occurs. For example, for a right lateral-moving fault, a bend to the right will result in stretching and consequent subsidence in the area of the irregularity. In the view of many geologists today, the Dead Sea lies in

832-569: The rift except at Whakaari / White Island , and the areas of maximal satellite measured subsidence were confined to a small areas of about 30 mm (1.2 in)/year near the 2012 Te Māri eruptions site, or the rift geothermal power stations, while from Lake Taupō to the coast subsidence more usually peaked at about 15 mm (0.59 in)/year. The majority of the fault activity is normal faulting . While continental intraarc rifts such as this, and those associated with Mount Aso in Japan, and

864-548: The rift, and its normal faulting, terminates with east to west faulting in the Taupō Rift termination faults . At the scale of the tectonic plate boundary, the rift trends NE-SW (41 ± 2°) but within New Zealand this trend is presently at 30° south of Lake Taupō and is 55° at the Bay of Plenty coast. A significant change in the mean fault strike occurs just south of the Ōkataina Caldera . The normal fault trends range from N20°E in

896-459: The south to N45°E in the central and northern sectors. There is good evidence that the orientation of intra-arc strike and extension processes has been maintained for 4 million years in this region of New Zealand. The modern active rift ranges in width from 15 kilometres (9.3 mi) in the northern Bay of Plenty sector, to 40 kilometres (25 mi) beyond Lake Taupō . Significant faults may be separated by as little as 100 metres (330 ft) in

928-450: The tectonic normal faults. This is consistent with a mafic magma intrusion (rather than one associated with the rhyolytic eruptions of Taupō) causing pressure over predominantly time, rather than place perpendicular to the usual strain on these fault systems and has been seen elsewhere. This is consistent with seismicity rather than volcanic activity poses the main short-term hazard at Taupō Volcano. Taup%C5%8D Rift The Taupō Rift

960-493: The volcanoes having potential for worldwide impact. The recent volcanism of the Taupō Volcanic Zone has been divided into three segments, with a central rhyolitic segment, dominated by explosive caldera associated with more typical Island Arc type andesite - dacite stratovolcanoes in either surrounding segment. In the hundreds of faults and their segments, some have associations with volcanism, but most fault activity

992-611: The world's largest lakes are located in rift valleys. Lake Baikal in Siberia , a World Heritage Site , lies in an active rift valley. Baikal is both the deepest lake in the world and, with 20% of all of the liquid freshwater on earth, has the greatest volume. Lake Tanganyika , second by both measures, is in the Albertine Rift , the westernmost arm of the active East African Rift . Lake Superior in North America ,

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1024-614: Was a complete fault rupture of the Ngapouri-Rotomahana Fault just prior to the 1314±12 CE Kaharoa eruption of Mount Tarawera . The 2001 Taupō earthquake swarm started within a very constrained area of the Taupō Volcano under the northwestern portion of Lake Taupō within the Oruanui caldera. It spread out horizontally over time with small size predominantly strike-slip faulting constrained to zones associated with

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