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1881 Nicobar Islands Earthquake
The 1881 Nicobar Islands earthquake occurred at about 07:49 local time (01:49 UTC) on 31 December, with an epicentre beneath Car Nicobar. It occurred as two separate ruptures, the largest of which had an estimated magnitude of 7.9 on the moment magnitude scale and triggered a tsunami that was observed around the Bay of Bengal. It is probably the earliest earthquake for which rupture parameters have been estimated instrumentally. Tectonic setting The Nicobar Islands are a series of volcanic islands that are part of an active volcanic arc, formed above the subduction zone where the Indo-Australian Plate passes beneath the Burma Plate. The convergence along this plate boundary is highly oblique, with the plate vector running at a low angle to the boundary. Most of the strike-slip component of the convergence is accommodated by the Great Sumatran fault, which passes northwards into the Andaman Sea spreading centre. This plate boundary has been the location of many historical meg ... [...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] |
Mid-ocean Ridge
A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary. The rate of seafloor spreading determines the morphology of the crest of the mid-ocean ridge and its width in an ocean basin. The production of new seafloor and oceanic lithosphere results from mantle upwelling in response to plate separation. The melt rises as magma at the linear weakness between the separating plates, and emerges as lava, creating new oceanic crust and lithosphere upon cooling. The first discovered mid-ocean ridge was the Mid-Atlantic Ridge, which is a spreading center that bisects the North and South Atlantic basins; hence the origin of the name 'mid-ocean ridge'. Most oceanic spreading centers are not in the middle of their hosting ocean basis but regardless, are traditionally called mid-ocean rid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sumatra
Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent islands such as the Simeulue, Nias, Mentawai, Enggano, Riau Islands, Bangka Belitung and Krakatoa archipelago. Sumatra is an elongated landmass spanning a diagonal northwest–southeast axis. The Indian Ocean borders the northwest, west, and southwest coasts of Sumatra, with the island chain of Simeulue, Nias, Mentawai, and Enggano off the western coast. In the northeast, the narrow Strait of Malacca separates the island from the Malay Peninsula, which is an extension of the Eurasian continent. In the southeast, the narrow Sunda Strait, containing the Krakatoa Archipelago, separates Sumatra from Java. The northern tip of Sumatra is near the Andaman Islands, while off the southeastern coast lie the islands of Bangka and Belitung, Karim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burma
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explains, the English spellings of both Myanmar and Burma assume a non-rhotic variety of English, in which the letter r before a consonant or finally serves merely to indicate a long vowel: mjænmɑː, ˈbɜːmə So the pronunciation of the last syllable of Myanmar as ɑːror of Burma as ɜːrməby some speakers in the UK and most speakers in North America is in fact a spelling pronunciation based on a misunderstanding of non-rhotic spelling conventions. The final ''r'' in ''Myanmar'' was not intended for pronunciation and is there to ensure that the final a is pronounced with the broad ''ah'' () in "father". If the Burmese name my, မြန်မာ, label=none were spelled "Myanma" in English, this would be pronounced at the end by all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mangalore
Mangalore (), officially known as Mangaluru, is a major port city of the Indian state of Karnataka. It is located between the Arabian Sea and the Western Ghats about west of Bangalore, the state capital, 20 km north of Karnataka–Kerala border, 297 km south of Goa. Mangalore is the state's only city to have all four modes of transport—air, road, rail and sea. The population of the urban agglomeration was 619,664 national census of India. It is known for being one of the locations of the Indian strategic petroleum reserves. The city developed as a port in the Arabian Sea during ancient times, and has since become a major port of India that handles 75 percent of India's coffee and cashew exports. It is also the country's seventh largest container port. Mangalore has been ruled by several major powers, including the Kadambas, Alupas, Vijayanagar Empire, Keladi Nayaks, and the Portuguese. The city was a source of contention between the British a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kathmandu
, pushpin_map = Nepal Bagmati Province#Nepal#Asia , coordinates = , subdivision_type = Country , subdivision_name = , subdivision_type1 = Province , subdivision_name1 = Bagmati Province , subdivision_type2 = District , subdivision_name2 = Kathmandu , established_title = , founder = Manjushri , parts_type = No. of Wards , parts = 32 , seat_type = , seat = , government_footnotes = , government_type = Mayor–council government , governing_body = Kathmandu Metropolitan Government, , leader_title = Mayor , leader_name = Balendra Shah ( Ind.) , leader_title1 = Deputy mayor , leader_name1 = Sunita Dangol (UML) , leader_title2 = Executive Officer , leader_name2 = Basanta Adhikari , unit_pref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kolkata
Kolkata (, or , ; also known as Calcutta , the official name until 2001) is the capital of the Indian state of West Bengal, on the eastern bank of the Hooghly River west of the border with Bangladesh. It is the primary business, commercial, and financial hub of Eastern India and the main port of communication for North-East India. According to the 2011 Indian census, Kolkata is the seventh-most populous city in India, with a population of 45 lakh (4.5 million) residents within the city limits, and a population of over 1.41 crore (14.1 million) residents in the Kolkata Metropolitan Area. It is the third-most populous metropolitan area in India. In 2021, the Kolkata metropolitan area crossed 1.5 crore (15 million) registered voters. The Port of Kolkata is India's oldest operating port and its sole major riverine port. Kolkata is regarded as the cultural capital of India. Kolkata is the second largest Bengali-speaking city after Dhaka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colombo
Colombo ( ; si, කොළඹ, translit=Koḷam̆ba, ; ta, கொழும்பு, translit=Koḻumpu, ) is the executive and judicial capital and largest city of Sri Lanka by population. According to the Brookings Institution, Colombo metropolitan area has a population of 5.6 million, and 752,993 in the Municipality. It is the financial centre of the island and a tourist destination. It is located on the west coast of the island and adjacent to the Greater Colombo area which includes Sri Jayawardenepura Kotte, the legislative capital of Sri Lanka, and Dehiwala-Mount Lavinia. Colombo is often referred to as the capital since Sri Jayawardenepura Kotte is itself within the urban/suburban area of Colombo. It is also the administrative capital of the Western Province and the district capital of Colombo District. Colombo is a busy and vibrant city with a mixture of modern life, colonial buildings and monuments. Due to its large harbour and its strategic position along th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Banda Aceh
Banda Aceh ( Acehnese: ''Banda Acèh'', Jawoë: كوتا بند اچيه) is the capital and largest city in the province of Aceh, Indonesia. It is located on the island of Sumatra and has an elevation of . The city covers an area of and had a population of 223,446 people at the 2010 Census,Biro Pusat Statistik, Jakarta, 2011. rising to 252,899 at the 2020 Census. The official estimate as at mid 2021 was 255,029.Badan Pusat Statistik, Jakarta, 2022. Banda Aceh is located on the northwestern tip of Indonesia at the mouth of the Aceh River. Banda Aceh itself is a semi-enclave within Aceh Besar Regency, as Banda Aceh is surrounded by Aceh Besar to the south, east, and west, while it borders with the Strait of Malacca to the north. The city was originally established as Bandar Aceh Darussalam Kandang and served as a capital and hub for the Sultanate of Aceh upon its foundation in the late 15th century. Later its name was changed to ''Bandar Aceh Darussalam'', and then it became p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chennai
Chennai (, ), formerly known as Madras ( the official name until 1996), is the capital city of Tamil Nadu, the southernmost Indian state. The largest city of the state in area and population, Chennai is located on the Coromandel Coast of the Bay of Bengal. According to the 2011 Indian census, Chennai is the sixth-most populous city in the country and forms the fourth-most populous urban agglomeration. The Greater Chennai Corporation is the civic body responsible for the city; it is the oldest city corporation of India, established in 1688—the second oldest in the world after London. The city of Chennai is coterminous with Chennai district, which together with the adjoining suburbs constitutes the Chennai Metropolitan Area, the 36th-largest urban area in the world by population and one of the largest metropolitan economies of India. The traditional and de facto gateway of South India, Chennai is among the most-visited Indian cities by foreign tourists. It was ranked the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Macroseismic Scale
The European macroseismic scale (EMS) is the basis for evaluation of seismic intensity in European countries and is also used in a number of countries outside Europe. Issued in 1998 as an update of the test version from 1992, the scale is referred to as EMS-98. Overview The history of the EMS began in 1988 when the European Seismological Commission (ESC) decided to review and update the Medvedev–Sponheuer–Karnik scale (MSK-64), which was used in its basic form in Europe for almost a quarter of a century. After more than five years of intensive research and development and a four-year testing period, the new scale was officially released. In 1996 the XXV General Assembly of the ESC in Reykjavík passed a resolution recommending the adoption of the new scale by the member countries of the European Seismological Commission. The European macroseismic scale EMS-98 is the first seismic intensity scale designed to encourage co-operation between engineers and seismologists, rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand Volcano
Sand boils or sand volcanoes occur when water under pressure wells up through a bed of sand. The water looks like it is boiling up from the bed of sand, hence the name. Sand volcano A sand volcano or sand blow is a cone of sand formed by the ejection of sand onto a surface from a central point. The sand builds up as a cone with slopes at the sand's angle of repose. A crater is commonly seen at the summit. The cone looks like a small volcanic cone and can range in size from millimetres to metres in diameter. The process is often associated with soil liquefaction and the ejection of fluidized sand that can occur in water-saturated sediments during an earthquake. The New Madrid Seismic Zone exhibited many such features during the 1811–12 New Madrid earthquakes. Adjacent sand blows aligned in a row along a linear fracture within fine-grained surface sediments are just as common, and can still be seen in the New Madrid area. In the past few years, much effort has gone into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
