|
2009 Tsunami
The 2009 Samoa earthquake and tsunami took place on 29 September 2009 in the southern Pacific Ocean adjacent to the Kermadec-Tonga subduction zone. The submarine earthquake occurred in an Extensional tectonics, extensional environment and had a moment magnitude scale, moment magnitude of 8.1 and a maximum Modified Mercalli intensity scale, Mercalli intensity of VI (''Strong''). It was the List of 21st-century earthquakes#2009, largest earthquake of 2009. The earthquake initiated with a normal-faulting event with a magnitude of 8.1. Within two minutes of the earthquake rupture, two large magnitude 7.8 earthquakes occurred on the subduction zone interface. The two magnitude 7.8 earthquakes had a combined magnitude equivalent to 8.0. The event can be considered a doublet earthquake. Normal and thrust faulting triggered a tsunami which caused substantial damage and loss of life in Samoa, American Samoa, and Tonga. The Pacific Tsunami Warning Center recorded a rise in sea levels near ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault (geology)
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A ''fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can blur the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hiroo Kanamori
is a Japanese seismologist who has made fundamental contributions to understanding the physics of earthquakes and the tectonic processes that cause them. Career Kanamori and American seismologist Thomas C. Hanks developed the moment magnitude scale which replaced the Richter magnitude scale as a measurement of the relative strength of earthquakes. Kanamori invented the method for calculating slip distribution on the fault plane by teleseismic waveform with Masayuki Kikuchi. In addition, they studied realtime seismology. In 2007 he was awarded the Kyoto Prize in Basic Sciences. Kanamori developed a new method of earthquake early warning detection by rapid analysis of the P-wave by a robust network. The algorithm is currently being tested with the Southern California Seismic Network "ShakeAlert" Earthquake Early Warning (EEW) system, and is one of three algorithms that is used by the system. Honours *1993 Arthur L. Day Prize and Lectureship *1994 Asahi Prize *1996 Walter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niue
Niue (, ; niu, Niuē) is an island country in the South Pacific Ocean, northeast of New Zealand. Niue's land area is about and its population, predominantly Polynesian, was about 1,600 in 2016. Niue is located in a triangle between Tonga, Samoa, and the Cook Islands. It is 604 kilometres northeast of Tonga. The island is commonly referred to as "The Rock", which comes from the traditional name "Rock of Polynesia". Niue is one of the world's largest coral islands. The terrain of the island has two noticeable levels. The higher level is made up of a limestone cliff running along the coast, with a plateau in the centre of the island reaching approximately 60 metres (200 feet) above sea level. The lower level is a coastal terrace approximately 0.5 km (0.3 miles) wide and about 25–27 metres (80–90 feet) high, which slopes down and meets the sea in small cliffs. A coral reef surrounds the island, with the only major break in the reef being in the central western c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokelau
Tokelau (; ; known previously as the Union Islands, and, until 1976, known officially as the Tokelau Islands) is a dependent territory of New Zealand in the southern Pacific Ocean. It consists of three tropical coral atolls: Atafu, Nukunonu, and Fakaofo. They have a combined land area of . The capital rotates yearly among the three atolls. In addition to these three, Swains Island, which forms part of the same archipelago, is the subject of an ongoing territorial dispute; it is currently administered by the United States as part of American Samoa. Tokelau lies north of the Samoan Islands, east of Tuvalu, south of the Phoenix Islands, southwest of the more distant Line Islands, and northwest of the Cook Islands. Tokelau has a population of approximately 1,500 people; it has the fourth-smallest population of any sovereign state or dependency in the world. As of the 2016 census, around 45% of its residents had been born overseas, mostly in Samoa or New Zealand. The populace has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rarotonga
Rarotonga is the largest and most populous of the Cook Islands. The island is volcanic, with an area of , and is home to almost 75% of the country's population, with 13,007 of a total population of 17,434. The Cook Islands' Parliament buildings and Rarotonga International Airport, international airport are on Rarotonga. Rarotonga is a very popular tourist destination with many resorts, hotels and motels. The chief town, Avarua, on the north coast, is the capital of the Cook Islands. Captain John Dibbs, master of the colonial brig ''Endeavour'', is credited as the European discoverer on 25 July 1823, while transporting the missionary Reverend John Williams (missionary), John Williams. Geography Rarotonga is a kidney-shaped volcanic island, in circumference, and wide on its longest (east-west) axis. The island is the summit of an extinct Pliocene or Pleistocene volcano, which rises 5000 meters from the seafloor. The island was formed between 2.3 to 1.6 million years ago, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulcanology
Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma and related geological, geophysical and geochemical phenomena (volcanism). The term ''volcanology'' is derived from the Latin word '' vulcan''. Vulcan was the ancient Roman god of fire. A volcanologist is a geologist who studies the eruptive activity and formation of volcanoes and their current and historic eruptions. Volcanologists frequently visit volcanoes, especially active ones, to observe volcanic eruptions, collect eruptive products including tephra (such as ash or pumice), rock and lava samples. One major focus of enquiry is the prediction of eruptions; there is currently no accurate way to do this, but predicting eruptions, like predicting earthquakes, could save many lives. Modern volcanology image:Icelandic tephra.JPG, Volcanologist examining tephra horizons in south-central Iceland. In 1841, the first volcanological observatory, the Vesuvius Observatory, was founded in the Kingdom o ... [...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] |
Plate Tectonics
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Ring Of Fire
The Ring of Fire (also known as the Pacific Ring of Fire, the Rim of Fire, the Girdle of Fire or the Circum-Pacific belt) is a region around much of the rim of the Pacific Ocean where many Types of volcanic eruptions, volcanic eruptions and earthquakes occur. The Ring of Fire is a Horseshoe, horseshoe-shaped belt about long and up to about wide. The Ring of Fire includes the Pacific coasts of South America, North America and Kamchatka, and some islands in the western Pacific Ocean. Although there is consensus among geologists about almost all areas which are included in the Ring of Fire, they disagree about the inclusion or exclusion of a few areas, for example, the Antarctic Peninsula and western Indonesia. The Ring of Fire is a direct result of plate tectonics: specifically the movement, collision and destruction of lithosphere, lithospheric plates (e.g. the Pacific Plate) under and around the Pacific Ocean. The collisions have created a nearly continuous series of subdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outer Trench Swell
The outer trench swell, outer trench high, or outer rise is a subtle ridge on the seafloor near an oceanic trench, where a descending plate begins to flex and fault in preparation for its descent into the mantle at a subduction zone. The lithosphere is bent upwards by plate stresses, and is not in isostatic equilibrium (distinguish from the "outer ridge" of a forearc). Characteristics Typically, the gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ... field over the outer swell is about 50 mGal (0.5 mm/s²) higher than expected from isostasy, while gravity over the oceanic trench, trench is about 200 mGal (2 mm/s²) less than that expected from isostatic considerations. The bending of the plate is associated with tension in the upper 20 km, and shallow earthqua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stuff
Stuff, stuffed, and stuffing may refer to: *Physical matter *General, unspecific things, or entities Arts, media, and entertainment Books *''Stuff'' (1997), a novel by Joseph Connolly (author), Joseph Connolly *''Stuff'' (2005), a book by Jeremy Strong (author), Jeremy Strong Fictional character *A flying creature in the video game ''Kya: Dark Lineage'' Film *''The Stuff'', a 1985 horror/comedy film by Larry Cohen *Stuff (film), ''Stuff'' (film), a 1993 documentary about John Frusciante's life Illustration *Henry Wright (artist), Henry Wright (1849–1937), worked for ''Vanity Fair'' under the pseudonym "Stuff" Music *Stuff (Holly McNarland album), ''Stuff'' (Holly McNarland album), 1997 *Stuff (band), a 1970s-1980s fusion/rhythm and blues music group **Stuff (Stuff album), ''Stuff'' (Stuff album) *''Stuff'', a 1992 album by Bill Wyman *Stuff (song), "Stuff" (song), a 2000 single by Diamond Rio from the album ''One More Day'' *Stuff (Eleanor McEvoy album), ''Stuff'' (Eleanor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicenter
The epicenter, epicentre () or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates. Surface damage Before the instrumental period of earthquake observation, the epicenter was thought to be the location where the greatest damage occurred, but the subsurface fault rupture may be long and spread surface damage across the entire rupture zone. As an example, in the magnitude 7.9 Denali earthquake of 2002 in Alaska, the epicenter was at the western end of the rupture, but the greatest damage was about away at the eastern end. Focal depths of earthquakes occurring in continental crust mostly range from . Continental earthquakes below are rare whereas in subduction zone earthquakes can originate at depths deeper than . Epicentral distance During an earthquake, seismic waves propagate in all directions from the hypocenter. Seismic shadowing occurs on the opposite s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
