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South Kermadec Ridge Seamounts
The South Kermadec Ridge Seamounts are a continuation of the volcanic island arc, formed at the convergent boundary where the Pacific Plate subducts under the Indo-Australian Plate. The subducting Pacific Plate created the Kermadec Trench, the second deepest submarine trench, to the east of the islands. The seamounts lie along the western aspect of the undersea Kermadec Ridge, which runs southwest from the Kermadec Islands towards the North Island of New Zealand and northeast towards Tonga (Kermadec-Tonga Arc). This area of the Kermadec Arc - Havre Trough is a relatively young oceanic arc-back-arc system as it became active in the Quaternary. The seamounts include: * Speight Knoll * Oliver Knoll * Haungaroa Seamount * Kuiwai Seamount * Cole Seamount * Ngātoroirangi Seamount * Sonne Seamount * Kibblewhite Seamount * Gill Seamount **Situated in the middle of a deep basin (3000m deep) to the west of Kibblewhite and actually closer to the Lau-Colville Ridge than the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Pacific Ocean
South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþaz'' ("south"), possibly related to the same Proto-Indo-European root that the word ''sun'' derived from. Some languages describe south in the same way, from the fact that it is the direction of the sun at noon (in the Northern Hemisphere), like Latin meridies 'noon, south' (from medius 'middle' + dies 'day', cf English meridional), while others describe south as the right-hand side of the rising sun, like Biblical Hebrew תֵּימָן teiman 'south' from יָמִין yamin 'right', Aramaic תַּימנַא taymna from יָמִין yamin 'right' and Syriac ܬܰܝܡܢܳܐ taymna from ܝܰܡܝܺܢܳܐ yamina (hence the name of Yemen, the land to the south/right of the Levant). Navigation By convention, the ''bottom or down-facing side'' of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kermadec-Tonga Arc
The Tonga-Kermadec Ridge is an oceanic ridge in the south-west Pacific Ocean underlying the Tonga-Kermadec island arc. It is the most linear, fastest converging, and most seismically active subduction boundary on Earth, and consequently has the highest density of submarine volcanoes. The Tonga-Kermadec Ridge stretches more than north-northeast from New Zealand's North Island. The Pacific Plate subducts westward beneath the Australian Plate along the ridge. It is divided into two segments, the northern Tonga Ridge and southern Kermadec Ridge, by the Louisville Seamount Chain. On its western side, the ridge is flanked by two back-arc basins, the Lau Basin and Havre Trough, that began opening at 6 and 2 Ma respectively. Together with these younger basins the ridge forms the eastward-migrating, 100 Ma-old Lau-Tonga-Havre-Kermadec arc/back-arc system or complex. The extension in the Lau-Havre basin results in a higher rate of subduction than convergence along the Au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecoregions Of New Zealand
{{use dmy dates, date=August 2019 This is a list of ecoregions of New Zealand as defined by the World Wide Fund for Nature. Tropical and subtropical moist broadleaf forests * Kermadec Islands subtropical moist forests Temperate broadleaf and mixed forests * Chatham Islands temperate forests * Fiordland temperate forests * Nelson Coast temperate forests * North Island temperate forests * Northland temperate kauri forests * Rakiura Island temperate forests * Richmond temperate forests * Southland temperate forests *Westland temperate forests Temperate grasslands, savannas, and shrublands * Canterbury–Otago tussock grasslands Montane grasslands and shrublands * Southland montane grasslands Tundra *Antipodes Subantarctic Islands tundra New Zealand Ecoregions Ecoregions An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism Of New Zealand
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. While the land's volcanism dates back to before the Zealandia microcontinent rifted away from Gondwana 60–130 million years ago, activity continues today with minor eruptions occurring every few years. This recent activity is primarily due to the country'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. New Zealand's rocks record examples of almost every kind of volcanism observed on Earth, including some of the world's largest eruptions in geologically recent times. None of the South Island's volcanoes are active. Major eruptions New Zealand has been the site of many large explosive eruptions during the last two million years, including several of supervo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seamounts Of New Zealand
A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to in height. They are defined by oceanographers as independent features that rise to at least above the seafloor, characteristically of conical form.IHO, 2008. Standardization of Undersea Feature Names: Guidelines Proposal form Terminology, 4th ed. International Hydrographic Organization and Intergovernmental Oceanographic Commission, Monaco. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. After they have subsided and sunk below the sea surface such flat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seamount Chains
A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to in height. They are defined by oceanographers as independent features that rise to at least above the seafloor, characteristically of conical form.IHO, 2008. Standardization of Undersea Feature Names: Guidelines Proposal form Terminology, 4th ed. International Hydrographic Organization and Intergovernmental Oceanographic Commission, Monaco. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. After they have subsided and sunk below the sea surface such flat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whakatāne Seamount
Whakatāne ( , ) is the seat of the Bay of Plenty region in the North Island of New Zealand, east of Tauranga and north-east of Rotorua, at the mouth of the Whakatāne River. Whakatāne District is the encompassing territorial authority, which covers an area to the south and west of the town, excluding the enclave of Kawerau District. Whakatāne has an urban population of , making it New Zealand's 33rd-largest urban area, and the Bay of Plenty's third-largest urban area (behind Tauranga and Rotorua). Another people live in the rest of the Whakatāne District. Around 42% of the population identify as having Māori ancestry and 66% as having European/Pākehā ancestry, compared with 17% and 72% nationally (some people identify with multiple ethnicities). Whakatāne forms part of the parliamentary electorate of East Coast, currently represented by Kiri Allan of the New Zealand Labour Party. The town is the main urban centre of the eastern Bay of Plenty sub-region, which incorp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clark Seamount
Clark is a dormant submarine volcano located off the northern coast of New Zealand and is one of the South Kermadec Ridge Seamounts. History The first evidence of the existence of Clark was found during 1988 GLORIA side-scan mapping. These interpretations were later confirmed via photography and oceanic dredging in early 1992 during the 3-week ''Rapuhia'' cruise. In 2006, during a New Zealand-American NOAA Vents Program expedition, sulfide Sulfide (British English also sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to chemical compounds lar ... chimneys and diffuse hydrothermal venting were observed. There have been no known eruptions of Clark. See also References {{Reflist Submarine volcanoes Seamounts of New Zealand Volcanoes of New Zealand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Healy Seamount
James Healy Seamount (former names Healy Seamount, Healy Volcano) is a submarine volcano located among the South Kermadec Ridge Seamounts south of New Zealand's Kermadec Islands. It consists of a volcanic cone that reaches a depth of below sea level, two and wide calderas and a parasitic cone that reaches a depth of below sea level. The flanks of the volcano are covered with pumice and volcanic rocks, and hydrothermal venting occurs inside the caldera. The caldera appears to have formed in one large explosive eruption that may have generated a pumice raft. Parts of the "Loisels Pumice" in New Zealand are suspected to have originated in this eruption, which took place 590±80 years before present (1950). Healy is also suspected to be the source of a tsunami that impacted Maori communities during the 15th century, and may be a continuing tsunami hazard. Geography and geology Regional The seafloor northeast of New Zealand is dominated by four structures, from eas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brothers Seamount
The Brothers Seamount (also Brothers Volcano) is a Pacific Ocean submarine volcano in the Kermadec Arc, north east of New Zealand's Whakaari/White Island. It is one of the South Kermadec Ridge Seamounts. Geology It was formed by volcanic activity within a graben structure delimited by regional faults created by subduction of the Pacific Plate under the Australian Plate. Within its oval outline, which measures , it contains a wide caldera with walls high. It is three times bigger than Whakaari / White Island. A dacite dome named the Upper Cone rises 350 m from the caldera floor (which lies 1850 m below sea level), with a smaller dome just to its northeast. There is now detailed magnetic anomaly mapping of the Brothers caldera with very extreme range variation from −2000 to +2000 nT. Such mapping has shown that the local magnetic highs correlate with the morphology of the caldera, in particular its rim and the Upper Cone, whereas magnetic lows correlate with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kermadec Ridge
The Tonga-Kermadec Ridge is an oceanic ridge in the south-west Pacific Ocean underlying the Tonga-Kermadec Islands, Kermadec island arc. It is the most linear, fastest converging, and most seismically active subduction boundary on Earth, and consequently has the highest density of submarine volcanoes. The Tonga-Kermadec Ridge stretches more than north-northeast from New Zealand's North Island. The Pacific Plate subduction, subducts westward beneath the Australian Plate along the ridge. It is divided into two segments, the northern Tonga Ridge and southern Kermadec Ridge, by the Louisville Ridge, Louisville Seamount Chain. On its western side, the ridge is flanked by two back-arc basins, the Lau Basin and Havre Trough, that began opening at 6 and 2 Ma respectively. Together with these younger basins the ridge forms the eastward-migrating, 100 Ma-old Lau-Tonga-Havre-Kermadec arc/back-arc system or complex. The extension in the Lau-Havre basin results in a higher r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
