Manawahe Fault | |
---|---|
Etymology | Manawahe |
Coordinates | 37°57′50″S176°40′16″E / 37.964°S 176.671°E |
Country | New Zealand |
Region | Bay of Plenty Region |
Characteristics | |
Range | Mw 6.3 [1] |
Length | 14 km (8.7 mi) [1] |
Strike | ENE [1] |
Displacement | 3 mm (0.12 in)/yr [1] |
Tectonics | |
Plate | Indo-Australian |
Status | Active, recurrence is 1580–2000 years [1] |
Type | Normal fault [1] |
Age | Holocene ~ |
Volcanic arc/belt | Taupō Volcanic Zone |
New Zealand Active Fault database |
The Manawahe Fault line is a seismically active area in the Bay of Plenty Region of the central North Island of New Zealand with the potential to be involved with other faults in an Mw 7.0 event. [1]
North of Lake Rotoma, volcanic ignimbrite sheets from multiple eruptions of the Ōkataina Caldera extend towards the Whakatane Graben with the volcanic region being separated from the tectonic Whakatane portion of the Taupō Rift by the Manawahe Fault. [1] The fault continues to east and coast in the Matata Fault line. The Manawahe Fault consists of a series of closely-spaced, mainly SSE-dipping fault traces, which are parallel to the North Rotoma Fault at the edge of the north eastern edge of the Rotoma Caldera. The traces are presumed to merge within 3 km (1.9 mi) of the surface. [1] The Manawahe Fault ruptured immediately prior to the 5500 years ago Whakatane eruption of the Ōkataina Caldera and also ruptured several times, associated with the Rotoma Caldera eruptive sequence, and immediately after the Mamaku eruption. [1]
This intra-rift fault has certainly ruptured several times in the last 10,000 years. [2] The last rupture identified was 636 years ago, with recurrence intervals between 1580–2000 years of a fault with one of the highest slip rates so far defined in the Taupō Volcanic Zone. [1] Although potentially ruptures could be up to Mw 7 if the fault ruptured at the same time as the longer Matata fault, only > Mw 5.5 can be definitely assigned on displacements characterised to date as there appears to have never been a single full length fault rupture which would result in a Mw 6.3event. [1]
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. 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. 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 as well as other landforms associated with its containing tectonic intra-arc continental Taupō Rift.
Mount Tarawera is a volcano on the North Island of New Zealand within the older but volcanically productive Ōkataina Caldera. Located 24 kilometres southeast of Rotorua, it consists of a series of rhyolitic lava domes that were fissured down the middle by an explosive basaltic eruption in 1886. This eruption was one of New Zealand's largest historical eruptions, and killed an estimated 120 people. The fissures run for about 17 kilometres (11 mi) northeast-southwest.
Lake Rotoiti is a lake in the Bay of Plenty region of New Zealand. It is the northwesternmost in a chain of lakes formed within the Okataina Caldera. The lake is close to the northern shore of its more famous neighbour, Lake Rotorua, and is connected to it via the Ohau Channel. It drains to the Kaituna River, which flows into the Bay of Plenty near Maketu.
The Haroharo Caldera was a 26 by 16 km postulated volcanic feature in Taupō Volcanic Zone of the North Island, New Zealand within the larger and older Ōkataina Caldera. Since 2010 further studies have tended to use the terms Haroharo vent alignment, Utu Caldera, Matahina Caldera, Rotoiti Caldera and a postulated Kawerau Caldera to the features assigned to it.
Ōkataina Caldera is a massive, recently active volcanic caldera and its associated volcanoes located in Taupō Volcanic Zone of New Zealand's North Island. It is just east of the smaller Rotorua Caldera and southwest of the much smaller Rotomā Embayment which is usually regarded as an associated volcano. It is best known for its high rates of explosive rhyolitic volcanism although its last eruption was basaltic. Confusingly the postulated Haroharo Caldera contained within it, has sometimes been described in almost interchangeable terms with the Ōkataina Caldera or volcanic complex or centre and by other authors as a separate complex. Since 2010 other terms such as the Haroharo vent alignment, Utu Caldera, Matahina Caldera, Rotoiti Caldera and a postulated Kawerau Caldera have replaced this classification.
The relatively small Rotomā Caldera is in the Taupō Volcanic Zone in the North Island of New Zealand.
Maunga Kākaramea is a 743 metres (2,438 ft) high dacite volcano located between Rotorua and Taupō in the North Island Volcanic Plateau. It has multiple steaming features and a picturesque crater lake reached by a short walk from the nearest road and has a nearby geothermal area.
Maungaongaonga is an 825 metres (2,707 ft) high dacite volcano located between Rotorua and Taupō in the North Island Volcanic Plateau. The area of the mountain is a scenic reserve and some of its southern slopes are highly geothermally active.
The Paeroa Fault is a seismically active area in the Taupō District, Waikato Region of the central North Island of New Zealand.
The Taupō Rift is the seismically active rift valley containing the Taupō Volcanic Zone, central North Island of New Zealand.
The Ngapouri-Rotomahana Fault is a seismically and volcanically active area of the central North Island of New Zealand.
The Ohakuri Caldera was formed in a paired single event eruption of Ohakuri ignimbrite and is located in the Taupo Volcanic Zone on the North Island of New Zealand. Its significance was first recognised in 2004, as the geology of the area had been misunderstood until then. The paired eruption resulted in a very large eruption sequence in the Taupō Volcanic Zone about 240,000 years ago that included the formation of Lake Rotorua.
The Ōkareka Embayment is a volcanic feature in Taupo Volcanic Zone of New Zealand. It most significant recent volcanic eruption was about 15,700 years ago and this deposited the widespread Rotorua tephra that reached beyond Auckland.
The Horohoro Fault is in the old Taupō Rift of the central North Island of New Zealand.
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 Waikato River bisects the western region of the belt.
Much of the volcanic activity in the northern portions of the North Island of New Zealand is recent in geological terms and has taken place over the last 30 million years. This is primarily due to the North Island's position on the boundary between the Indo-Australian and Pacific Plates, a part of the Pacific Ring of Fire, and particularly the subduction of the Pacific Plate under the Indo-Australian Plate. The activity has included some of the world's largest eruptions in geologically recent times and has resulted in much of the surface formations of the North Island being volcanic as shown in the map.
The Rotoiti Caldera is a postulated, mainly infilled sub caldera of the Ōkataina Caldera based upon gravitational and magnetic evidence. It erupted 100 cubic kilometres (24 cu mi) of magma that is used in the recent stratigraphy of much of the northern North Island. It was formed in the larger paired eruption with the lesser Earthquake Flat vents linked by tectonic interaction across the length of the Ōkataina Caldera. The series of eruptions was about 50,000 years ago, with the resulting widespread Rotoiti ignimbrite and several layers of Rotoiti/Rotoehu tephra/brecca/ash giving challenges in consistent dating. It was subsequently infilled by later eruptive activity to a depth of over 2 km (1.2 mi). The paired eruptions may have erupted about 240 cubic kilometres (58 cu mi) of tephra.
The Whakatāne Graben is a predominantly normal faulting tectonic feature of the northeastern most aspect of the young, modern Taupō Rift in New Zealand. At the coast it is widening by about 7 mm (0.28 in)/year. This very geologically active graben was the site of the 1987 Edgecumbe earthquake, which caused up to 2 m of land subsidence. The discontinuity in the Taupō Volcanic Zone's faults imposed by the highly active Ōkataina Volcanic Centre, geography and geology mean the graben includes the actively expanding and lowering region onshore extending towards the coast, but some scientists have used the term to refer to only the offshore continuation of the Taupō Rift.
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 Mw 7.0 event.
The Rangipo Fault is the eastern Taupō rift-bounding north–south striking normal fault complex of the Ruapehu Graben, a seismically active area of the central North Island of New Zealand to the west of Mount Ruapehu. It could be part of a Mw7.1 potential rupture.