Mount Tarawera | |
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![]() Fissure formed during 1886 Tarawera eruption | |
Highest point | |
Elevation | 1,111 [1] m (3,645 ft) |
Coordinates | 38°13′00″S176°31′00″E / 38.21667°S 176.51667°E Coordinates: 38°13′00″S176°31′00″E / 38.21667°S 176.51667°E |
Geography | |
Geology | |
Age of rock | 21,900 years |
Mountain type | Lava dome with fissure vent |
Volcanic arc/belt | Taupō Volcanic Zone |
Last eruption | May 1981 (Waimangu) June 1951 (Rotomahana) June to August 1886 (Tarawera) |
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.
The volcano's component domes include Ruawahia Dome (the highest at 1,111 metres), Tarawera Dome and Wahanga Dome. It is surrounded by several lakes, most of which were created or drastically altered by the 1886 eruption. These lakes include Lakes Tarawera, Rotomahana, Rerewhakaaitu, Ōkataina, Ōkareka, Tikitapu / Blue and Rotokākahi / Green. The Tarawera River runs northeastwards across the northern flank of the mountain from Lake Tarawera. In 2000, the mountain was ceded to the Ngāti Rangitihi sub-tribe of Te Arawa. In 2002, the group and their lessee stopped previously free public access to the mountain. This decision caused angst among Rotorua residents. [2]
While the 1886 eruption was basaltic, study has shown there was only a small basalt component to the previous recent rhyolitic predominant eruptions. [3]
The Ōkareka Tephra generating eruption has now been dated to 21,900 years before the present with a tephra volume of about 12 cubic kilometres (2.9 cu mi) but may be less, generated in days or weeks at the most. [4] The associated eruption mountain building appears to have been at both ends of the complex and includes present features at the eastern end such as the Rotomahana Dome (434 m (1,424 ft) [1] ) and Patiti Island (peak is 404 m (1,325 ft) [1] high) which is in the middle of Lake Rotomahana. Lava fields at the western end came from sources most likely buried in the Waiohau eruption, have a volume of at least 5 cubic kilometres (1.2 cu mi), [5] and would have taken several years to form. [4] The Ōkareka Embayment is a separate, but adjacent volcanic structure in the Ōkataina Caldera responsible for the Rotorua Tephra.
The Rerewhakaaitu eruption has been recently re-dated forward to about 17,700 years ago, at about the time of the last glacial termination, with a tephra volume of about 7.5 cubic kilometres (1.8 cu mi). [4] Other historic sources suggested a higher volume. It involved three rhyolite magmas with a total volume of about 5 cubic kilometres (1.2 cu mi) with the Rerewhakaaitu Tephra having 15 rhyolitic fall units. [4] The Southern (1,024 m (3,360 ft) [1] ) and Western (446 m (1,463 ft) [1] ) Domes were formed at this time and the lava excursion of 2 cubic kilometres (0.48 cu mi) [5] again lasted for several years after the much shorter tephra phase of the eruption. [4]
The Waiohau eruption occurred about 13,800 years ago (recently re-dated backward). [3] The Kanakana (925 m (3,035 ft) [1] ) and Eastern (529 m (1,736 ft) [1] ) Domes were formed. [4] The estimated total volume of the fifteen or more Waiohau Tephra eruptions and some lava is 2 cubic kilometres (0.48 cu mi). [6] During one of the eruptions structural collapse of the then mountain occurred. [6]
Mount Tarawera erupted 1314±12 CE [7] in the Kaharoa eruption. [8] [9] This was just a few years after the first Māori settlement about 1280 CE [10] although more wide spread settlement is now believed to have not taken place until 1320 to 1350 AD. [11] The Plinian phase of this eruption consisted of 11 discrete episodes of VEI 4 [12] although there are possibly two more discrete sub-Plinian phases in a two stage eruption from at least two different vents along a 8 km (5.0 mi) long fissure. [13] The total dense rock equivalent (DRE) was at least 9.1 km3 (2.2 cu mi). [13] The essential mineral poor Kaharoa Tephra which was a factor in New Zealand bush sickness was distributed from the east coast of the Northland Peninsula, down the Coromandel Peninsula and through beyond Tarawera to northern Hawke Bay at the Māhia Peninsula. [10] The total volume of material erupted was more than 5 times that of the 1886 eruption [14] and has been stated to be at least 15 km3 (3.6 cu mi) of tephra. [13] The Ruawahia (1,111 m (3,645 ft) [1] ), Tarawera(874 m (2,867 ft) [1] ), Wahanga(1,025 m (3,363 ft) [1] ) and Crater (1,095 m (3,593 ft) [1] ) Domes were formed. [4]
Shortly after midnight on the morning of 10 June 1886, a series of more than 30 increasingly strong earthquakes were felt in the Rotorua area [15] and by 2:45 am Mount Tarawera's three peaks had erupted, blasting three distinct columns of smoke and ash thousands of metres into the sky [16] At around 3.30 am, the largest phase of the eruption commenced; vents at Rotomahana produced a pyroclastic surge that destroyed several villages within a 6 kilometer radius, and the Pink and White Terraces appeared to be obliterated. [17] Recent research using mathematical modelling of events during the later Rotomahana eruption phase, is consistent with eyewitness accounts; describing it resembling a pot boiling over. [18] [19]
Settlements inhabited by Ngāti Rangitihi and Tūhourangi around the Ariki arm of Lake Tarawera, including Moura, Koutu, Kokotaia, Piripai, Pukekiore and Otuapane, Tapahoro, Te Wairoa, Totarariki, and Waingongoro, were buried or destroyed. Of these, Te Wairoa is now a tourist attraction and is described as the "buried village". The official death toll was reported as 153, and many more were displaced, making the eruption the most deadly in New Zealand history. [20] [21] [22] [23] The survivors became refugees in their own country, for generations.
The eruption was also believed to have destroyed the world-famous Pink and White Terraces. However, 125 years after the eruption a small portion of the Pink Terraces was reportedly rediscovered under Lake Rotomahana. [24] This was due to the discovery of a previously unknown 1859 survey of Lake Rotomahana by Ferdinand von Hochstetter, which was deciphered and published between 2016 and 2019. This unique primary data indicate the Pink, Black and White Terrace locations now lie along the present lake shores. There is a prospect the terraces or sections of them, may lie buried, and as a result the terraces can no longer be assumed destroyed. [25] [26] [27] [28]
One legend [29] surrounding the 1886 eruption is that of the phantom waka (canoe). Eleven days before the eruption, a boat full of tourists returning from the Terraces saw what appeared to be a waka approach their boat, only to disappear in the mist half a mile from them. One of the witnesses was a clergyman, a local Maori man from the Te Arawa iwi. Nobody around the lake owned such a war canoe, and nothing like it had been seen on the lake for many years. It is possible that the rise and fall of the lake level caused by pre-eruption fissures had freed a burial waka from its resting place. Traditionally, the dead were tied in an upright position. A number of letters have been published from the tourists who experienced the event.
Though skeptics maintained that it was a freak reflection seen on the mist, tribal elders at Te Wairoa claimed that it was a waka wairua (spirit canoe) and was a portent of doom. It has been suggested that the waka was actually a freak wave on the water, caused by seismic activity below the lake, but locals believe that a future eruption will be signalled by the reappearance of the waka. [ citation needed ]
It is within the Ōkataina Caldera of the Ōkataina Volcanic Centre in the central segment of the Taupō Volcanic Zone. This rhyolitic segment is dominated by explosive caldera. [30] The actual basaltic dyke of the 1886 eruption is 15 kilometres (9.3 mi) long and extends from the eruptive fissure of Mount Tarawera to Lake Rotomahana and has a remnant hydrothermal hot spot in the Waimangu Volcanic Rift Valley. [7] The dyke and linear line of vents align with the Taupō Rift at this point. [30]
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.
The Pink and White Terraces, were natural wonders of New Zealand. They were reportedly the largest silica sinter deposits on earth. Until recently, they were lost and thought destroyed in the 1886 eruption of Mount Tarawera, while new hydrothermal features formed to the south-west i.e. Waimangu Volcanic Rift Valley.
Lake Rotomahana is an 800-hectare (2,000-acre) lake in northern New Zealand, located 20 kilometres to the south-east of Rotorua. It is immediately south-west of the dormant volcano Mount Tarawera, and its geography was substantially altered by a major 1886 eruption of Mount Tarawera. Along with the mountain, it lies within the Okataina caldera.
Lake Tarawera is the largest of a series of lakes which surround the volcano Mount Tarawera in the North Island of New Zealand. Like the mountain, it lies within the Okataina caldera. It is located 18 kilometres (11 mi) to the east of Rotorua, and beneath the peaks of the Tarawera massif i.e. Wahanga, Ruawahia, Tarawera and Koa. The lake's surface area is 39 square kilometres (15 sq mi).
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 Waimangu Volcanic Rift Valley is the hydrothermal system created on 10 June 1886 by the volcanic eruption of Mount Tarawera, on the North Island of New Zealand. It encompasses Lake Rotomahana, the site of the Pink and White Terraces, as well as the location of the Waimangu Geyser, which was active from 1900 to 1904. The area has been increasingly accessible as a tourist attraction and contains Frying Pan Lake, which is the largest hot spring in the world, and the steaming and usually pale blue Inferno Crater Lake, the largest geyser-like feature in the world although the geyser itself cannot be seen since it plays at the bottom of the lake.
The volcanism of New Zealand has been responsible for many of the country's geographical features, especially in the North Island and the country's outlying islands.
George Dobson Valentine (1852–1890) was a Scottish photographer.
The region around the city of Rotorua, in New Zealand's North Island, contains several lakes. From biggest to smallest, these are Lake Rotorua, Lake Tarawera, Lake Rotoiti, Lake Rotoma, Lake Okataina, Lake Rotoehu, Lake Rotomahana, Lake Rerewhakaaitu, Lake Rotokakahi, Lake Okareka and Lake Tikitapu. There are also four smaller lakes: Lake Okaro/Ngakaro, Lake Rotokawa, Lake Rotokawau and Lake Rotongata. Most of the lakes have formed due to volcanic activity. The region is part of the Taupo Volcanic Zone, the world's most active area of explosive silicic volcanic activity in geologically recent time.
In 1886, a violent eruption occurred at Mount Tarawera, near the city of Rotorua on New Zealand's North Island. At an estimated Volcanic Explosivity Index of 5, the eruption is the largest and deadliest in New Zealand during the past 500 years, which includes the entirety of European history in New Zealand. The eruption began in the early hours of 10 June 1886 and lasted for approximately 6 hours, causing a 10-kilometre-high (6.2 mi) ash column, earthquakes, lightning, and explosions to be heard as far away as Blenheim in the South Island — more than 500 kilometers away. A 17-kilometre-long (11 mi) rift formed across the mountain and surrounding area during the eruption, starting from the Wahanga peak at the mountain's northern end and extending in a southwesterly direction, through Lake Rotomahana and forming the Waimangu Volcanic Rift Valley.
Lake Rotokawau is a small volcanic lake 4.1 km (2.5 mi) east of Lake Rotorua in the Bay of Plenty region of New Zealand's North Island. The name is also used for lakes in the Kaipara District, Chatham Islands, on Aupouri Peninsula and near Lake Waikare in Waikato. Access is via Lake Rotokawau Road, from SH30 at Tikitere. The lake is owned and managed by Ngāti Rangiteaorere.
The Maroa Caldera is approximately 16 km × 25 km in size and is located in the north-east corner of the earlier Whakamaru caldera in the Taupo Volcanic Zone in the North Island of New Zealand.
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 Ngapouri-Rotomahana Fault is a seismically and volcanically active area of the central North Island of New Zealand.
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.