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Banks Peninsula Volcano
The Banks Peninsula Volcano is an extinct volcanic complex to the east of Christchurch on New Zealand's South Island.Sewell 1986 While the volcano is highly eroded it still forms the majority of Banks Peninsula with a highest point of . It is a composite of two main eruptive centers one originating at Lyttelton Harbour, the other at Akaroa Harbour. The eruptions were predominantly basaltic, with associated andesite and trachytes, with minor rhyolite. The volcanic activity occurred in the Late Miocene and possibly extended into the Early Pliocene. There are four volcanic groups, all of which are within the Māui Supergroup.Mortimer et al. 2014 The Christchurch earthquakes led to rumors of a possible eruption, however, there is no known magma chamber beneath the volcano and there has not been any sign of volcanic activity in the last 5 million years. Origin and relationship to other volcanoes New Zealand's South Island has many extinct volcanic centers with no obvious tectonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex Volcano
A complex volcano, also called a compound volcano or a volcanic complex, is a mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock. They may form due to changes in eruptive habit or in the location of the principal vent area on a particular volcano. Stratovolcanoes can also form a large caldera that gets filled in by a lava dome, or else multiple small cinder cones, lava domes and craters may develop on the caldera's rim. Although a comparatively unusual type of volcano, they are widespread in the world and in geologic history. Metamorphosed ash flow tuffs are widespread in the Precambrian rocks of northern New Mexico, which indicates that caldera complexes have been important for much of Earth's history. Yellowstone National Park is on three partly covered caldera complexes. The Long Valley Caldera in eastern California is also a complex volcano; the San Juan Mountains in southwestern Colorado are formed on a group of N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2011 Christchurch Earthquake
A major earthquake occurred in Christchurch on Tuesday 22 February 2011 at 12:51 p.m. local time (23:51 UTC, 21 February). The () earthquake struck the entire of the Canterbury region in the South Island, centred south-east of the central business district. It caused widespread damage across Christchurch, killing 185 people, in New Zealand's fifth-deadliest disaster. Christchurch's central city and eastern suburbs were badly affected, with damage to buildings and infrastructure already weakened by the magnitude 7.1 Canterbury earthquake of 4 September 2010 and its aftershocks. Significant liquefaction affected the eastern suburbs, producing around 400,000 tonnes of silt. The earthquake was felt across the South Island and parts of the lower and central North Island. While the initial quake only lasted for approximately 10 seconds, the damage was severe because of the location and shallowness of the earthquake's focus in relation to Christchurch as well as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zealandia
Zealandia (pronounced ), also known as (Māori) or Tasmantis, is an almost entirely submerged mass of continental crust that subsided after breaking away from Gondwanaland 83–79 million years ago.Gurnis, M., Hall, C.E., and Lavier, L.L., 2004, Evolving force balance during incipient subduction: Geochemistry, Geophysics, Geosystems, v. 5, Q07001, https://doi.org/10.01029/02003GC000681 It has been described variously as a submerged continent, a continental fragment (or microcontinent), and a continent. The name and concept for Zealandia was proposed by Bruce Luyendyk in 1995, and satellite imagery shows it to be almost the size of Australia. A 2021 study suggests Zealandia is 1 billion years old, about twice as old as geologists previously thought. By approximately 23 million years ago the landmass may have been completely submerged. Today, most of the landmass (94%) remains submerged beneath the Pacific Ocean. New Zealand is the largest part of Zealandia that is above sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asthenosphere
The asthenosphere () is the mechanically weak and ductile region of the upper mantle of Earth. It lies below the lithosphere, at a depth between ~ below the surface, and extends as deep as . However, the lower boundary of the asthenosphere is not well defined. The asthenosphere is almost solid, but a slight amount of melting (less than 0.1% of the rock) contributes to its mechanical weakness. More extensive decompression melting of the asthenosphere takes place where it wells upwards, and this is the most important source of magma on Earth. It is the source of mid-ocean ridge basalt (MORB) and of some magmas that erupted above subduction zones or in regions of continental rifting. Characteristics The asthenosphere is a part of the upper mantle just below the lithosphere that is involved in plate tectonic movement and isostatic adjustments. It is composed of peridotite, a rock containing mostly the minerals olivine and pyroxene. The lithosphere-asthenosphere boundary is con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaiian Islands
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kure Atoll. Formerly the group was known to Europeans and Americans as the Sandwich Islands, a name that James Cook chose in honor of the 4th Earl of Sandwich, the then First Lord of the Admiralty. Cook came across the islands by chance when crossing the Pacific Ocean on his Third Voyage in 1778, on board HMS ''Resolution''; he was later killed on the islands on a return visit. The contemporary name of the islands, dating from the 1840s, is derived from the name of the largest island, Hawaii Island. Hawaii sits on the Pacific Plate and is the only U.S. state that is not geographically connected to North America. It is part of the Polynesia subregion of Oceania. The state of Hawaii occupies the archipelago almost in its entirety (includin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithosphere
A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust (geology), crust and the portion of the upper mantle (geology), mantle that behaves elastically on time scales of up to thousands of years or more. The crust and upper mantle (Earth), upper mantle are distinguished on the basis of chemistry and mineralogy. Earth's lithosphere Earth's lithosphere, which constitutes the hard and rigid outer vertical layer of the Earth, includes the crust and the uppermost mantle. The lithosphere is underlain by the asthenosphere which is the weaker, hotter, and deeper part of the upper mantle. The lithosphere–asthenosphere boundary is defined by a difference in response to stress. The lithosphere remains rigid for very long periods of geologic time in which it deforms elastically and through brittle failure, while the asthenosphere deforms viscously and accommodates strain through plasticity (physics), pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunedin Volcano
The Dunedin Volcano is an extensively eroded multi-vent shield volcano that was active between 16 and 10 million years ago. It originally extended from the modern city of Dunedin, New Zealand to Aramoana about 25 km away. Extensive erosion has occurred over the last 10 million years and Otago Harbour now fills the oldest parts of the volcano. The remnants of the volcano form the hills around Otago Harbour (including Mount Cargill, Flagstaff, Saddle Hill, Signal Hill, and Otago Peninsula). Volcanism began in a shallow marine environment. The volcano became larger with flows of basalt and minor trachyte creating the bulk of the volcano. The final phase of eruptions are preserved as phonolite domes around Mount Cargill. Traces of the old Dunedin Volcano are best seen in the Dunedin Botanic Garden's geology walk, the cliffs at Aramoana and the geomorphology of Mount Cargill which has preserved lava domes. Basaltic columns are also to be found as prominent features above Second B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chatham Islands
The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about ten islands within an approximate radius, the largest of which are Chatham Island and Pitt Island (Rangiauria). They include New Zealand's easternmost point, the Forty-Fours. Some of the islands, formerly cleared for farming, are now preserved as nature reserves to conserve some of the unique flora and fauna. The islands were uninhabited when the Moriori people arrived around 1500 CE and developed a peaceful way of life. In 1835 members of the Ngāti Mutunga and Ngāti Tama Māori iwi from the North Island of New Zealand invaded the islands and nearly exterminated the Moriori, enslaving the survivors. Later during the period of European colonisation of New Zealand, the New Zealand Company claimed that the British Crown had never include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canterbury, New Zealand
Canterbury ( mi, Waitaha) is a region of New Zealand, located in the central-eastern South Island. The region covers an area of , making it the largest region in the country by area. It is home to a population of The region in its current form was established in 1989 during nationwide local government reforms. The Kaikoura District joined the region in 1992 following the abolition of the Nelson-Marlborough Regional Council. Christchurch, the South Island's largest city and the country's second-largest urban area, is the seat of the region and home to percent of the region's population. Other major towns and cities include Timaru, Ashburton, Rangiora and Rolleston. History Natural history The land, water, flora, and fauna of Waitaha/Canterbury has a long history stretching from creation of the greywacke basement rocks that make up the Kā Tiritiri o te Moana/Southern Alps to the arrival of the first humans. This history is linked to the creation of the earth, the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otago
Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government region. Its population was The name "Otago" is the local southern Māori dialect pronunciation of "Ōtākou", the name of the Māori village near the entrance to Otago Harbour. The exact meaning of the term is disputed, with common translations being "isolated village" and "place of red earth", the latter referring to the reddish-ochre clay which is common in the area around Dunedin. "Otago" is also the old name of the European settlement on the harbour, established by the Weller Brothers in 1831, which lies close to Otakou. The upper harbour later became the focus of the Otago Association, an offshoot of the Free Church of Scotland, notable for its adoption of the principle that ordinary people, not the landowner, should choose the ministe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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