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Hatepe Eruption
The Hatepe eruption, named for the Hatepe Plinian pumice tephra layer, sometimes referred to as the Taupō eruption or Horomatangi Reef Unit Y eruption, is dated to 232 CE ± 10 and was Taupō Volcano's most recent major eruption. It is thought to be New Zealand's largest eruption within the last 20,000 years. The eruption ejected some of bulk tephra, of which just over was ejected in approximately 6–7 minutes. This makes it one of the largest eruptions in the last 5,000 years, comparable to the Minoan eruption in the 2nd millennium BCE, the 946 eruption of Paektu Mountain, the 1257 eruption of Mount Samalas, and the 1815 eruption of Mount Tambora. Stages of the eruption The eruption went through several stages, with six distinct marker horizons identified, although phase 5 has at least 26 deposit subunits. Most of the stages only affected the immediate surrounds of the caldera and regions to its east due to prevailing wind patterns. Despite the uniform comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Taupō
Lake Taupō (also spelled Taupo; or ) is a large crater lake in New Zealand's North Island, located in the caldera of Taupō Volcano. The lake is the namesake of the town of Taupō, which sits on a bay in the lake's northeastern shore. With a surface area of , it is the largest lake by surface area in New Zealand, and the second largest freshwater lake by surface area in geopolitical Oceania after Lake Murray in Papua New Guinea. Motutaiko Island lies in the southeastern area of the lake. Geography Lake Taupō has a perimeter of approximately and a maximum depth of . It is drained by the Waikato River (New Zealand's longest river), and its main tributaries are the Waitahanui River, the Tongariro River, and the Tauranga Taupō River. It is a noted trout fishery with stocks of introduced brown and rainbow trout. The level of the lake is controlled by Mercury Energy, the owner of the eight hydroelectric dams on the Waikato River downstream of Lake Taupō, using gates b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and volcanic gas, gas bubbles. Magma is produced by melting of the mantle (geology), mantle or the Crust (geology), crust in various tectonics, tectonic settings, which on Earth include subduction zones, continental rift (geology), rift zones, mid-ocean ridges and Hotspot (geology), hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal mush, crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by Fractional crystallization (geology), fractional crystallization, contaminati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsunami Deposit
A tsunami deposit (the term tsunamiite is also sometimes used) is a sedimentary unit deposited as the result of a tsunami. Such deposits may be left onshore during the inundation phase or offshore during the 'backwash' phase. Such deposits are used to identify past tsunami events and thereby better constrain estimates of both earthquake and tsunami hazards. There remain considerable problems, however, in distinguishing between deposits caused by tsunamis and those caused by storms or other sedimentary processes. Tsunamiite The term "tsunamiite" or "tsunamite" was introduced in the 1980s to describe deposits interpreted to have been formed by traction processes associated with tsunamis and is particularly used for marine deposits formed during the "backwash" phase. The term's application has broadened to encompass all tsunami-related deposits, but its use has been challenged. The main criticism of the term is that it describes deposits that have formed by many different processes th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Māori People
Māori () are the Indigenous peoples of Oceania, indigenous Polynesians, Polynesian people of mainland New Zealand. Māori originated with settlers from East Polynesia, who arrived in New Zealand in several waves of Māori migration canoes, canoe voyages between roughly 1320 and 1350. Over several centuries in isolation, these settlers developed Māori culture, a distinct culture, whose language, mythology, crafts, and performing arts evolved independently from those of other eastern Polynesian cultures. Some early Māori moved to the Chatham Islands, where their descendants became New Zealand's other indigenous Polynesian ethnic group, the Moriori. Early contact between Māori and Europeans, starting in the 18th century, ranged from beneficial trade to lethal violence; Māori actively adopted many technologies from the newcomers. With the signing of the Treaty of Waitangi, Treaty of Waitangi/Te Tiriti o Waitangi in 1840, the two cultures coexisted for a generation. Rising ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, transports it to another location where it is deposit (geology), deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by Solvation, dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and Wind wave, waves; glacier, glacial Plucking (glaciation), plucking, Abrasion (geology), abrasion, and scour; areal flooding; Aeolian processes, wind abrasion; groundwater processes; and Mass wastin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Ruapehu
Mount Ruapehu (; English ) is an active stratovolcano at the southern end of the Taupō Volcanic Zone and North Island North Island Volcanic Plateau, volcanic plateau in New Zealand. It is northeast of Ohakune and southwest of the southern shore of Lake Taupō, within Tongariro National Park. The North Island's major ski resorts and only glaciers are on its slopes. Ruapehu, the largest active volcano in New Zealand, has the highest point in the North Island and has three major peaks: Tahurangi (2,797 m), Te Heuheu (2,755 m) and Paretetaitonga (2,751 m). The deep, active volcanic crater, crater is between the peaks and fills with water between major eruptions, being known as Crater Lake (). The name ''Ruapehu'' means "pit of noise" or "exploding pit" in Māori language, Māori. Geography Ruapehu is located in the centre of the North Island of New Zealand, northeast of Ohakune, New Zealand, and southwest of the southern shore of Lake Taupō, within Tongariro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrounding atmosphere. New Zealand geologist Patrick Marshall (1869–1950) coined the term ''ignimbrite'' from the Latin ''igni-'' [fire] and ''imbri-'' [rain]. Ignimbrites are made of a very poorly sorted mixture of volcanic ash (or tuff when Lithification, lithified) and pumice lapilli, commonly with scattered lithic fragments. The ash is composed of glass shards and crystal fragments. Ignimbrites may be loose and unconsolidated, or lithified (solidified) rock called lapilli tuff. Near the volcanic source, ignimbrites often contain thick accumulations of lithic blocks, and distally, many show meter-thick accumulations of rounded cobbles of pumice. Ignimbrites may be white, grey, pink, beige, brown, or black depending on their composition and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Tongariro
Mount Tongariro (; ) is a compound volcano in the Taupō Volcanic Zone of the North Island of New Zealand. It is located to the southwest of Lake Taupō, and is the northernmost of the three active volcanoes that dominate the landscape of the central North Island. Geology Mount Tongariro is part of the Tongariro volcanic centre, which consists of four massifs made of andesite: Tongariro, Kakaramea-Tihia Massif, Pihanga, and Ruapehu at the southern end of the North Island Volcanic Plateau. The andesitic eruptions formed Tongariro, a steep stratovolcano, reaching a height of . Tongariro is composed of layers of both lava and tephra and the eruptions that built the current stratovolcano commenced about 275,000 years ago. Tongariro consists of at least 12 cones. Ngauruhoe, while often regarded as a separate mountain, is geologically a cone of Tongariro. It is also the most active vent, having erupted more than 70 times since 1839, the last episode in 1973 to 1975. Activ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaimanawa Ranges
The Kaimanawa Range, officially called the Kaimanawa Mountains since 16 July 2020, is a range of mountains in the central North Island of New Zealand. They extend for 50 kilometres in a northeast–southwest direction through largely uninhabited country to the south of Lake Taupō, east of the "Desert Road". Their slopes form part of the North Island Volcanic Plateau. The New Zealand Ministry for Culture and Heritage gives a translation of "breath for food" for ''Kaimanawa''. The lands around the mountains are scrubby. To the west, where the Rangipo Desert is located, the soils are poor quality. To the east, the soils are more fertile, but the land is very rough. A population of feral horses, the Kaimanawa horses, roam free on the ranges. Unlike the majority of mountain ranges in New Zealand, the Kaimanawa Range is divided into private land. Considerable areas of the Rangipo Desert are used by the New Zealand Army for training. Demographics Kaimanawa covers and had an estimat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waitahanui
Waitahanui is a village in the Taupō District, Waikato, Waikato region, New Zealand. The village is on the eastern shore of Lake Taupō, south of the district seat of Taupō. Waitahanui Marae and Pākira meeting house is a meeting place for the Ngāti Tūwharetoa hapū (subtribe) of Ngāti Hinerau and Ngāti Tutemohuta. The Waitahanui Bridge site is also a meeting place for the Ngāti Tūwharetoa hapū. Demographics Statistics New Zealand describes Five Mile Bay-Waitahanui as a rural settlement, which covers . It had an estimated population of as of with a population density of people per km2. The settlement is part of the larger Waitahanui statistical area. Five Mile Bay-Waitahanui had a population of 579 in the 2023 New Zealand census, an increase of 36 people (6.6%) since the 2018 New Zealand census, 2018 census, and an increase of 177 people (44.0%) since the 2013 New Zealand census, 2013 census. There were 288 males, 285 females, and 3 people of non-binary gender, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horomatangi Reef
The Horomatangi Reef or reefs is a feature of Lake Taupō, in the central North Island of New Zealand. The reef is named after Horomātangi (Horo-matangi), the tāniwha or water monster of the lake, who is said to reside in a cave adjacent to the nearby Motutaiko Island to the south. The name Horomatangi Reefs perhaps better reflects its complex inner and outer structure with the shallow reefs separated by very deep areas, so tends to be used in the geological literature, while the term reef tends to be used geographically. Geology The reefs are at a high heat-output geothermal hot spot area within the Taupō Volcano. This is related to rhyolitic lava domes extruded after explosive volcanism. The explosive eruptions include the VEI 7 Hatepe eruption of 232 ± 10 CE that ejected over of material (also known as Horomatangi Reef Unit Y eruption) and its linear line of eruption centres, as well as its own namesake Horomatangi, Unit S VEI 6 eruption of about 1460&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Dome
In volcanology, a lava dome is a circular, mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on Earth form lava domes. The geochemistry of lava domes can vary from basalt (e.g. Semeru, 1946) to rhyolite (e.g. Chaiten, 2010) although the majority are of intermediate composition (such as Santiaguito, dacite-andesite, present day). The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained in two ways: by high levels of silica in the magma, or by degassing of fluid magma. Since viscous basaltic and andesitic domes weather fast and easily break apart by further input of fluid lava, most of the preserved domes have high silica content and consist of rhyolite or dacite. Existence of lava domes has been suggested for some domed structures on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
