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1963 Marj Earthquake
The 1963 Marj earthquake occurred on February 21 in northern Libya. The earthquake occurred at with a moment magnitude of 5.6 and a maximum Mercalli intensity of VIII (''Severe''). Financial losses totaled $5 million USD, with 290–375 deaths, 375–500 injuries, and 12,000 homeless. Tectonic setting The northern part of Cyrenaica lies close to the northern edge of the African Plate. Offshore lies the Mediterranean Ridge, an accretionary wedge, developed above the destructive plate boundary where the African Plate is being subducted beneath the Aegean Sea Plate along the Hellenic subduction zone. The Cyrenaica promontory is thought to be undergoing incipient collision as the continental margin enters the subduction zone. The Cyrenaica region is characterised by relatively low magnitude earthquakes with thrust fault focal mechanisms, developed in a area of NE–SW directed maximum horizontal stress. Earthquake The earthquake's epicenter is located about 13 km to the nort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Libya
Libya (; ar, ليبيا, Lībiyā), officially the State of Libya ( ar, دولة ليبيا, Dawlat Lībiyā), is a country in the Maghreb region in North Africa. It is bordered by the Mediterranean Sea to the north, Egypt to Egypt–Libya border, the east, Sudan to Libya–Sudan border, the southeast, Chad to Chad–Libya border, the south, Niger to Libya–Niger border, the southwest, Algeria to Algeria–Libya border, the west, and Tunisia to Libya–Tunisia border, the northwest. Libya is made of three historical regions: Tripolitania, Fezzan, and Cyrenaica. With an area of almost 700,000 square miles (1.8 million km2), it is the fourth-largest country in Africa and the Arab world, and the List of countries and outlying territories by total area, 16th-largest in the world. Libya has the List of countries by proven oil reserves, 10th-largest proven oil reserves in the world. The largest city and capital, Tripoli, Libya, Tripoli, is located in western Libya and contains over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress (mechanics)
In continuum mechanics, stress is a physical quantity. It is a quantity that describes the magnitude of forces that cause deformation. Stress is defined as ''force per unit area''. When an object is pulled apart by a force it will cause elongation which is also known as deformation, like the stretching of an elastic band, it is called tensile stress. But, when the forces result in the compression of an object, it is called compressive stress. It results when forces like tension or compression act on a body. The greater this force and the smaller the cross-sectional area of the body on which it acts, the greater the stress. Therefore, stress is measured in newton per square meter (N/m2) or pascal (Pa). Stress expresses the internal forces that neighbouring particles of a continuous material exert on each other, while strain is the measure of the deformation of the material. For example, when a solid vertical bar is supporting an overhead weight, each particle in the bar pushe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquakes In Libya
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word ''tremor'' is also used for non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Oceanic And Atmospheric Administration
The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditions, charts the seas, conducts deep sea exploration, and manages fishing and protection of marine mammals and endangered species in the U.S. exclusive economic zone. Purpose and function NOAA's specific roles include: * ''Supplying Environmental Information Products''. NOAA supplies to its customers and partners information pertaining to the state of the oceans and the atmosphere, such as weather warnings and forecasts via the National Weather Service. NOAA's information services extend as well to climate, ecosystems, and commerce. * ''Providing Environmental Stewardship Services''. NOAA is a steward of U.S. coastal and marine environments. In coordination with federal, state, local, tribal and international authorities, NOAA manages the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Geophysical Data Center
The United States National Geophysical Data Center (NGDC) provided scientific stewardship, products and services for geophysical data describing the solid earth, marine, and solar-terrestrial environment, as well as earth observations from space. In 2015, NGDC was merged with the National Climatic Data Center (NCDC) and the National Oceanographic Data Center (NODC) into the National Centers for Environmental Information (NCEI). Location and controlling bodies The NGDC, was located in Boulder, Colorado as a part of the US Department of Commerce (USDOC), National Oceanic & Atmospheric Administration (NOAA), National Environmental Satellite, Data and Information Service (NESDIS). Data holdings NGDC's data holdings contained more than 300 digital and analog databases, some of which were very large. As technology advanced, so did the search for more efficient ways of preserving these data. This data is now maintained by the NCEI. Data contributors NGDC worked closely with contri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing house specializing in monographs and scholarly journals. Most are nonprofit organizations and an integral component of a large research university. They publish work that has been reviewed by schola ... in the world. It is also the King's Printer. Cambridge University Press is a department of the University of Cambridge and is both an academic and educational publisher. It became part of Cambridge University Press & Assessment, following a merger with Cambridge Assessment in 2021. With a global sales presence, publishing hubs, and offices in more than 40 Country, countries, it publishes over 50,000 titles by authors from over 100 countries. Its publishing includes more than 380 academic journals, monographs, reference works, school and uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Earthquakes In 1963
This is a list of earthquakes in 1963. Only magnitude 6.0 or greater earthquakes appear on the list. Lower magnitude events are included if they have caused death, injury or damage. Events which occurred in remote areas will be excluded from the list as they wouldn't have generated significant media interest. All dates are listed according to UTC time. Maximum intensities are indicated on the Mercalli intensity scale and are sourced from United States Geological Survey (USGS) ShakeMap data. A fairly active year with 17 events reaching above magnitude 7.0. The intensity of the events was stronger with 2 measuring above magnitude 8. Both events came within 3 weeks of each other. The strongest of 1963 was in the Kuril Islands, Russia and was magnitude 8.5. Macedonia had by far the most of the 1,488 fatalities. A fairly modest magnitude 6.0 event in July resulted in 1,070 deaths and substantial destruction. Libya had one of the worst events in its history in February. Again a fairly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubble Masonry
Rubble stone is rough, uneven building stone not laid in regular courses. It may fill the core of a wall which is faced with unit masonry such as brick or ashlar. Analogously, some medieval cathedral walls are outer shells of ashlar with an inner backfill of mortarless rubble and dirt. Square Rubble Masonry Square Rubble Masonry is where face stones are dressed (squared on all joints and beds) before laying, set in mortar and appear as the outer surface of a wall. History The sack masonry is born as an evolution of embankment covered with boards, stones or bricks. The coating was used to give the embankment greater strength and make it more difficult for the enemies to climb. The Sadd el-Khafara dam, 14 meters high and built in sacking masonry in Wadi Al-Garawi near Helwan in Egypt, dates back to 2900 - 2600 BC The Greeks called the brickwork emplecton and made use of it in particular in the construction of the defensive walls of their poleis. The Romans made extensive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alluvial Plain
An alluvial plain is a largely flat landform created by the deposition of sediment over a long period of time by one or more rivers coming from highland regions, from which alluvial soil forms. A floodplain is part of the process, being the smaller area over which the rivers flood at a particular period of time, whereas the alluvial plain is the larger area representing the region over which the floodplains have shifted over geological time. As the highlands erode due to weathering and water flow, the sediment from the hills is transported to the lower plain. Various creeks will carry the water further to a river, lake, bay, or ocean. As the sediments are deposited during flood conditions in the floodplain of a creek, the elevation of the floodplain will be raised. As this reduces the channel floodwater capacity, the creek will, over time, seek new, lower paths, forming a meander (a curving sinuous path). The leftover higher locations, typically natural levees at the margins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aftershock
In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousands of instrumentally detectable aftershocks, which steadily decrease in magnitude and frequency according to a consistent pattern. In some earthquakes the main rupture happens in two or more steps, resulting in multiple main shocks. These are known as doublet earthquakes, and in general can be distinguished from aftershocks in having similar magnitudes and nearly identical seismic waveforms. Distribution of aftershocks Most aftershocks are located over the full area of fault rupture and either occur along the fault plane itself or along other faults within the volume affected by the strain associated with the main shock. Typically, aftershocks are found up to a distance equal to the rupture length away from the fault plane. The pattern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Seismological Centre
The International Seismological Centre (ISC) is a non-governmental, nonprofit organisation charged with the final collection, definitive analysis and publication of global seismicity. The ISC was formed in 1964 as an international organisation independent of national governments that would carry on the work of the International Seismological Summary in collecting and analyzing seismic data from around the world, and particularly to handle increased flow of data from the World-Wide Standard Seismograph Network (WWSSN), also established that year. The ISC considers its prime task to be the collection and re-analysis of all available earthquake seismic date in order to produce definitive data on earthquakes. The ISC's catalog is considered "the most complete and authoritative final depository of global earthquake parameter data." Purpose The main scientific goal of the Centre is the definitive compilation of earthquake information and the readings on which they are based. Collecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
