|
Mahuika Crater
Mahuika crater was a hypothesized impact crater named after the Māori god of fire. It was described as being about 20 ± 2 km (12.4 ± 1.2 mi) wide and over deep and on the New Zealand continental shelf at 48.3 South and 166.4 East, to the south of The Snares. A 2017 survey of the purported site found no evidence supporting the existence of the crater. Initial claims of discovery The crater was reported and named by Dallas Abbott and her colleagues from the Lamont–Doherty Earth Observatory at Columbia University.Abbott, D.H., A. Matzen, E.A. Bryant, and S.F. Pekar (2003) Did a bolide impact cause catastrophic tsunamis in Australia and New Zealand?'' Geological Society of America Abstracts with Programs. 35:168. Based on elemental anomalies, fossils, and minerals, which are interpreted to be derived from the impact, found in an ice core from the Siple Dome in Antarctica, it is argued that the impact which created the Mahuika crater occurred around 1443 AD, but other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Impact craters are typically circular, though they can be elliptical in shape or even irregular due to events such as landslides. Impact craters range in size from microscopic craters seen on lunar rocks returned by the Apollo Program to simple bowl-shaped depressions and vast, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth. Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury (planet), Mercury, Callisto (moon), Callisto, Ganymede (moon), Ganymede, and most small moons and asteroids. On other planet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RV Tangaroa
RV ''Tangaroa'' is a research vessel operated by the National Institute of Water and Atmospheric Research (NIWA) of New Zealand. It was purpose-built as a Deepwater Research Vessel for the then Ministry of Agriculture and Fisheries Research Centre at a cost of $27 million to replace the ageing GRV ''James Cook''. It has a DNV classification of 1A1 (stern trawler) and Ice 1C (sufficient strength and power to operate in ice floes up to thick). It was transferred to the new National Institute of Water and Atmospheric Research in 1992. ''Tangaroa'' operates for 320 to 340 days per year conducting fisheries research in New Zealand's Exclusive Economic Zone and marine research in the waters surrounding Antarctica. It is equipped for hydrographic, bathymetric and oceanographic surveys to measure and map various properties of the ocean and seabed; biological surveys; and for both acoustic and trawl fisheries surveys. It can trawl to and conduct acoustic soundings down to . In 2010 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene Impact Craters
The Holocene () is the current geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene is an interglacial period within the ongoing glacial cycles of the Quaternary, and is equivalent to Marine Isotope Stage 1. The Holocene correlates with the last maximum axial tilt towards the Sun of the Earth's obliquity. The Holocene corresponds with the rapid proliferation, growth, and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global significance for the future evolution of living species, including approximately synchronous lithospheric evidence, or more rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Possible Impact Craters On Earth
Possibility is the condition or fact of being possible. Latin origins of the word hint at ability. Possibility may refer to: * Probability, the measure of the likelihood that an event will occur * Epistemic possibility, a topic in philosophy and modal logic * Possibility theory, a mathematical theory for dealing with certain types of uncertainty and is an alternative to probability theory * Subjunctive possibility, (also called alethic possibility) is a form of modality studied in modal logic. ** Logical possibility, a proposition that will depend on the system of logic being considered, rather than on the violation of any single rule * Possible world, a complete and consistent way the world is or could have been Other * Possible (Italy), a political party in Italy * Possible Peru, a political party in Peru * Possible Peru Alliance, an electoral alliance in Peru Entertainment *'' Kim Possible'', a US children's TV series :* Kim Possible (character), the central chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of New Zealand
The geology of New Zealand is noted for its volcanic activity, earthquakes and Geothermal areas in New Zealand, geothermal areas because of its position on the boundary of the Australian Plate and Pacific Plates. New Zealand is part of Zealandia, a microcontinent nearly half the size of Australia that broke away from the Gondwanan supercontinent about 83 million years ago. New Zealand's early separation from other landmasses and subsequent evolution have created a unique fossil record and modern Environment of New Zealand, ecology. New Zealand's geology can be simplified into three phases. First the basement rocks of New Zealand formed. These rocks were once part of the super-continent of Gondwana, along with South America, Africa, Madagascar, India, Antarctica and Australia. The rocks that now form the mostly submerged continent of Zealandia were then nestled between Eastern Australia and Western Antarctica. Secondly New Zealand drifted away from Gondwana and many sedimentary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Possible Impact Structures On Earth
This list includes potential but unconfirmed structures that are not listed on the Earth Impact Database list of confirmed impact structures. For confirmed impact structures, see List of impact structures on Earth. List of confirmed and possible impact structures The following tables list geological features on Earth that are possible impact events, but for which there is currently no confirming scientific evidence in the peer-reviewed literature. In order for a structure to be List of impact craters on Earth, confirmed as an impact crater, it must meet a stringent set of well-established criteria. Some proposed impact structures are likely to eventually be confirmed, whereas others are likely to be shown to have been misidentified (see below). Recent extensive surveys have been done for Australian (2005), African (2014), and South American (2015) craters, as well as those in the Arab world (2016). A book review by A. Crósta and U. Reimold disputes some of the evidence presente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burckle Crater
The Burckle crater is an undersea topographic feature about in diameterAbbott et al., 2006 in the southwestern Indian Ocean. A team of Earth scientists called the Holocene Impact Working Group proposes the feature to be an impact crater; these claims are disputed by other geologists. Description Burckle Crater lies below the surface in the southern Indian Ocean at . It is east of Madagascar and west of Western Australia, adjacent to the mid-ocean Southwest Indian Ridge. Impact event and megatsunami hypothesis Burckle Crater's position was determined in 2006 by the Holocene Impact Working Group using prehistoric chevron dune formations in Australia and Madagascar. Based on a hypothesis that these dunes were formed by a megatsunami resulting from an impact, the researchers were able to triangulate the location of Burckle Crater. In 2009, geologists Jody Bourgeois and R. Weiss challenged the hypothesis that a megatsunami created the chevron dunes. Using a computer model ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Bathymetric Chart Of The Oceans
The General Bathymetric Chart of the Oceans (GEBCO) is a publicly available bathymetric chart of the world's oceans. The project was conceived with the aim of preparing a global series of charts showing the general shape of the seafloor. Over the years it has become a reference map of the bathymetry of the world's oceans for scientists and others. Organisation GEBCO operates under the joint auspices of the International Hydrographic Organization (IHO). and the Intergovernmental Oceanographic Commission (IOC) of UNESCO. Its work is done by an international group of experts in seafloor mapping who develop a range of bathymetric data sets and data products. Data sets and products Although originally GEBCO published paper contour charts, today it has moved into the digital age and collects digital depths of the ocean from wherever they are available. GEBCO provides a range of bathymetric data sets and data products, including: *Global gridded bathymetric data sets: **GEBCO_08 G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and sodar (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low ( infrasonic) to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multibeam Echosounder
A multibeam echosounder (MBES) is a type of sonar that is used to seafloor mapping, map the seabed. It emits acoustic waves in a fan shape beneath its transceiver. The time of flight, time it takes for the sound waves to reflect off the seabed and return to the receiver is used to calculate the water depth. Unlike other sonars and echo sounders, MBES uses beamforming to extract directional information from the returning soundwaves, producing a swathe of depth soundings from a single ping. History and progression Multibeam sonar sounding systems, also known as ''swathe'' (British English) or ''swath'' (American English) , originated for military applications. The concept originated in a radar system that was intended for the Lockheed U-2 high altitude reconnaissance aircraft, but the project was derailed when the aircraft flown by Gary Powers was brought down by a Soviet missile in May 1960. A proposal for using the "Mills Cross" beamforming technique adapted for use with bottom m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Institute Of Water And Atmospheric Research
The National Institute of Water and Atmospheric Research or NIWA (), is a Crown Research Institute of New Zealand. Established in 1992, NIWA conducts research across a broad range of disciplines in the environmental sciences. It also maintains nationally and, in some cases, internationally important environmental monitoring networks, databases, and collections. , NIWA had 697 staff spread across 14 sites in New Zealand and one in Perth, Australia. Its head office is in Auckland, with regional offices in Hamilton, Wellington, Christchurch, Nelson, and Lauder (Central Otago). It also has small field teams, focused mostly on hydrology, stationed in Bream Bay, Lake Tekapo, Rotorua, Napier, Whanganui, Greymouth, Alexandra, and Dunedin. NIWA maintains a fleet of about 30 vessels for freshwater, marine, and atmospheric research. On 1 July 2025 NIWA will become part of the new Public Research Organisation New Zealand Institute for Earth Science. History NIWA was formed as a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mahuika
Mahuika is a Māori fire deity and consort of the god Auahitūroa. Myths In some versions, she is the younger sister of Hine-nui-te-pō, goddess of death. It was from her that Māui (in some versions he is her grandson) obtained the secret of making fire. She married Auahitūroa and together they had five children, named for the five fingers on the human hand, called collectively Ngā Mānawa. The symbolism of this connection between toropuku (fingers) and fire is revealed in the stories where Māui obtains fire from Mahuika by tricking her into giving him her fingernails one by one. She is also said to have played a role in the formation of Rangitoto Island, asking Rūaumoko, god of earthquakes and eruptions, to destroy a couple that had cursed her. In some parts of New Zealand, Mahuika is a male deity. This is also the case in some parts of tropical Polynesia; for instance, in the Tuamotu archipelago and the Marquesas, Mahu-ika is the fire god who lives in the u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
