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Okhotsk Plate
The Okhotsk Plate is a minor tectonic plate covering the Kamchatka Peninsula, Magadan Oblast, and Sakhalin Island of Russia; Hokkaido, Kantō and Tōhoku regions of Japan; the Sea of Okhotsk, as well as the disputed Kuril Islands. It was formerly considered a part of the North American Plate, but recent studies indicate that it is an independent plate, bounded on the north by the North American Plate. The boundary is a left-lateral moving transform fault, the Ulakhan Fault originating from a triple junction in the Chersky Range. On the east, the plate is bounded by the Pacific Plate at the Kuril–Kamchatka Trench and the Japan Trench, on the south by the Philippine Sea Plate at the Nankai Trough, on the west by the Eurasian Plate, and on the southwest by the Amurian Plate. Geology The boundary between Okhotsk Plate and Amurian Plate might be responsible for many strong earthquakes that occurred in the Sea of Japan as well as in Sakhalin Island, such as the MW7.1 ( MS7.5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Tectonic Plates
This is a list of tectonic plates on Earth's surface. Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere. The plates are around thick and consist of two principal types of material: oceanic crust (also called ''sima'' from silicon and magnesium) and continental crust (''sial'' from silicon and aluminium). The composition of the two types of crust differs markedly, with mafic basaltic rocks dominating oceanic crust, while continental crust consists principally of lower-density felsic granitic rocks. Current plates Geologists generally agree that the following tectonic plates currently exist on Earth's surface with roughly definable boundaries. Tectonic plates are sometimes subdivided into three fairly arbitrary categories: ''major'' (or ''primary'') ''plates'', ''minor'' (or ''secondary'') ''plates'', and ''microplates'' (or ''tertiary plates''). Major plates These plates comprise the bulk of the continents and the P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan Trench
The Japan Trench is an oceanic trench part of the Pacific Ring of Fire off northeast Japan. It extends from the Kuril Islands to the northern end of the Izu Islands, and is at its deepest. It links the Kuril–Kamchatka Trench to the north and the Izu–Ogasawara Trench to its south with a length of . This trench is created as the oceanic Pacific plate subducts beneath the continental Okhotsk Plate (a microplate formerly a part of the North American Plate). The subduction process causes bending of the down going plate, creating a deep trench. Continuing movement on the subduction zone associated with the Japan Trench is one of the main causes of tsunamis and earthquakes in northern Japan, including the megathrust Tōhoku earthquake and resulting tsunami that occurred on 11 March 2011. The rate of subduction associated with the Japan Trench has been recorded at about /yr. Tectonic history During the late Neogene period (23.03-2.58 million years ago), the Japan Trench underwent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction Zone
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the dens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1993 Okushiri Earthquake
The or Okushiri earthquake occurred at 13:17:12 UTC on 12 July 1993 in the Sea of Japan near the island of Hokkaido.Japan Meteorological Agency officially named this earthquake 平成5年(1993年)北海道南西沖地震 (''Heisei 5 nen (1993 nen) Hokkaidō nansei-oki jishin'', literally ''the 1993 Southwest-off Hokkaido Earthquake'')気象庁が命名した気象及び地震火山現象 It had a magnitude of 7.7 on the moment magnitude scale and a maximum felt intensity of VIII (''Severe'') on the Mercalli intensity scale. It triggered a major tsunami that caused deaths on Hokkaidō and in southeastern Russia, with a total of 230 fatalities recorded. The island of Okushiri was hardest hit, with 165 casualties from the earthquake, the tsunami and a large landslide. Tectonic setting The northwestern side of Honshu lies on the southeastern margin of the Sea of Japan, an area of oceanic crust created by back-arc spreading associated with the convergent boundary where the Pacific Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1983 Sea Of Japan Earthquake
The year 1983 saw both the official beginning of the Internet and the first mobile cellular telephone call. Events January * January 1 – The migration of the ARPANET to TCP/IP is officially completed (this is considered to be the beginning of the true Internet). * January 24 – Twenty-five members of the Red Brigades are sentenced to life imprisonment for the 1978 murder of Italian politician Aldo Moro. * January 25 ** High-ranking Nazi war criminal Klaus Barbie is arrested in Bolivia. ** IRAS is launched from Vandenberg AFB, to conduct the world's first all-sky infrared survey from space. February * February 2 – Giovanni Vigliotto goes on trial on charges of polygamy involving 105 women. * February 3 – Prime Minister of Australia Malcolm Fraser is granted a double dissolution of both houses of parliament, for elections on March 5, 1983. As Fraser is being granted the dissolution, Bill Hayden resigns as leader of the Australian Labor Party, and in the subsequent lea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraplate Earthquake
The term intraplate earthquake refers to a variety of earthquake that occurs ''within the interior'' of a tectonic plate; this stands in contrast to an interplate earthquake, which occurs ''at the boundary'' of a tectonic plate. Intraplate earthquakes are often called "intraslab earthquakes", especially when occurring in microplates. Intraplate earthquakes are relatively rare compared to the more familiar boundary-located interplate earthquakes. Structures far from plate boundaries tend to lack seismic retrofitting, so large intraplate earthquakes can inflict heavy damage. Examples of damaging intraplate earthquakes are the devastating Gujarat earthquake in 2001, the 2012 Indian Ocean earthquakes, the 2017 Puebla earthquake, the 1811–1812 earthquakes in New Madrid, Missouri, and the 1886 earthquake in Charleston, South Carolina. Fault zones within tectonic plates The surface of the Earth is made up of seven primary and eight secondary tectonic plates, plus dozens of terti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neftegorsk, Sakhalin Oblast
Neftegorsk (), formerly Vostok (, lit. ''east'') before 1970, is a ghost town in Sakhalin Oblast, Russia. Building The city was built in 1963. It was an urban-type oil-mining settlement, with its name meaning "Oil Town". Construction Minister Yefim Basin decided not to rebuild it after its destruction. Destruction It was devastated on May 28, 1995 by an earthquake, which measured 7.1 on the Richter scale, killing 2,040 people out of a total population of 3,197. An oil-producing town in northern Sakhalin, all buildings in Neftegorsk suffered extensive damage and many were completely destroyed, as they had been built with low quality concrete and were not designed to withstand seismic activity. The majority of the victims were killed by the rubble of their apartment buildings collapsing. Neftegorsk was almost totally flattened, and it was decided not to be rebuilt, instead a memorial was constructed in the area. Many survivors were relocated to other towns in Sakhalin such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1995 Neftegorsk Earthquake
__NOTOC__ The 1995 Neftegorsk earthquake occurred on 28 May at on northern Sakhalin Island in the Russian Far East. It was the most destructive earthquake known within the current territory of Russia, with a magnitude of and maximum Mercalli intensity of IX (''Violent'') that devastated the oil town of Neftegorsk, where 1,989 of its 3,977 citizens were killed, and another 750 injured. 90% of the victims were killed by the collapse of 17 five-story residential buildings. While Western media generally attributed the collapses to allegedly poor construction and shoddy materials of Soviet-era construction, a geotechnical study faulted a failure to accommodate the possibility of soil liquefaction in an area that was considered "practically aseismic". The Belgian Centre for Research on the Epidemiology of Disasters' EM-DAT database places the total damage at $64.1 million, while the United States' National Geophysical Data Center assesses the damage at $300 million. This quake wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Wave Magnitude
The surface wave magnitude (M_s) scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements of Rayleigh surface waves that travel along the uppermost layers of the Earth. This magnitude scale is related to the local magnitude scale proposed by Charles Francis Richter in 1935, with modifications from both Richter and Beno Gutenberg throughout the 1940s and 1950s. It is currently used in People's Republic of China as a national standard (GB 17740-1999) for categorising earthquakes. Recorded magnitudes of earthquakes through the mid 20th century, commonly attributed to Richter, could be either M_s or M_L. Definition The formula to calculate surface wave magnitude is: :M_s = \log_\left(\frac\right)_ + \sigma(\Delta)\,, where A is the maximum particle displacement in surface waves (vector sum of the two horizontal displacements) in μm, T is the corresponding period in s (usually 20 2 seconds), Δ is the epi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moment Magnitude Scale
The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 paper by Thomas C. Hanks and Hiroo Kanamori. Similar to the local magnitude scale, local magnitude/Richter scale () defined by Charles Francis Richter in 1935, it uses a logarithmic scale; small earthquakes have approximately the same magnitudes on both scales. Despite the difference, news media often says "Richter scale" when referring to the moment magnitude scale. Moment magnitude () is considered the authoritative magnitude scale for ranking earthquakes by size. It is more directly related to the energy of an earthquake than other scales, and does not saturate—that is, it does not underestimate magnitudes as other scales do in certain conditions. It has become the standard scale used by seismological authorities like the U.S. Geological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Of Japan
The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific Ocean. This isolation also affects faunal diversity and salinity, both of which are lower than in the open ocean. The sea has no large islands, bays or capes. Its water balance is mostly determined by the inflow and outflow through the straits connecting it to the neighboring seas and the Pacific Ocean. Few rivers discharge into the sea and their total contribution to the water exchange is within 1%. The seawater has an elevated concentration of dissolved oxygen that results in high biological productivity. Therefore, fishing is the dominant economic activity in the region. The intensity of shipments across the sea has been moderate owing to political issues, but it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amurian Plate
The Amurian Plate (or Amur Plate; also occasionally referred to as the China Plate, not to be confused with the South China Subplate) is a minor tectonic plate in the northern and eastern hemispheres. It covers Manchuria, the Korean Peninsula, the Sea of Japan, Shikoku, Kyushu, southwest Honshu (Kansai, Chūgoku), eastern Mongolia and the south of Russian Far East. Once thought to be a part of the Eurasian Plate, the Amurian Plate is now generally considered to be a separate plate moving southeast with respect to the Eurasian Plate. The Amurian Plate is named after the Amur River, which forms the border between the Russian Far East and Northeastern China. It is bounded on the north, west, and southwest by the Eurasian Plate, on the east by the Okhotsk Plate, to the southeast by the Philippine Sea Plate along the Suruga Trough and the Nankai Trough, and the Okinawa Plate, and the Yangtze Plate.Yu. F. Malyshev, et al. Deep structure of the Amur lithospheric Plate border zone. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
