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1982 North Yemen Earthquake
The 1982 North Yemen earthquake hit near the city of Dhamar, North Yemen (now part of Yemen) on December 13. Measuring 6.2 on the moment magnitude scale, with a maximum perceived intensity of VIII (''Severe'') on the Mercalli intensity scale, as many as 2,800 people were killed and another 1,500 injured. The shock occurred within several hundred kilometers of a plate boundary in a geologically complex region that includes active volcanoes and seafloor spreading ridges. Yemen has a history of destructive earthquakes, though this was the first instrumentally recorded event to be detected on global seismograph networks. Tectonic setting The southwestern portion of the Arabian Plate lies adjacent to the Afar Triple Junction (an area of spreading ridges) near the Red Sea. The triple junction marks the intersecting point of the Arabian, African, and Somali plates. Spreading initiated around 5 mya and persists at 6–7.5 mm per year in the southern Red Sea and ~10 mm per ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USGS Shakemap - 1982 North Yemen Earthquake
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 hundredth anniv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Earthquake Information Center
The National Earthquake Information Center (abbreviated NEIC) is part of the United States Geological Survey (USGS) located on the campus of the Colorado School of Mines in Golden, Colorado. The NEIC has three main missions: * First, the NEIC determines, as rapidly and as accurately as possible, the location and size of all significant earthquakes that occur worldwide. The NEIC disseminates this information immediately to concerned national and international agencies, scientists, critical facilities, and the general public. * Second, the NEIC collects and provides to scientists and to the public an extensive seismic database that serves as a solid foundation for scientific research, principally through the operation of modern digital national and global seismograph networks and through cooperative international agreements. The NEIC is the U.S. national data center and archive for earthquake information. * Third, the NEIC pursues an active research program to improve its ability to l ... [...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 King Henry VIII in 1534, it is the oldest university press 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 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 university textbooks, and English language teaching and learning publications. It also publishes Bibles, runs a bookshop in Cambridge, sells through Amazon, and has a conference venues business in Cambridge at the Pitt Building and the Sir Geoffrey Cass Sports and Social Centre. ... [...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 extens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adobe
Adobe ( ; ) is a building material made from earth and organic materials. is Spanish for '' mudbrick''. In some English-speaking regions of Spanish heritage, such as the Southwestern United States, the term is used to refer to any kind of earthen construction, or various architectural styles like Pueblo Revival or Territorial Revival. Most adobe buildings are similar in appearance to cob and rammed earth buildings. Adobe is among the earliest building materials, and is used throughout the world. Adobe architecture has been dated to before 5,100 B.C. Description Adobe bricks are rectangular prisms small enough that they can quickly air dry individually without cracking. They can be subsequently assembled, with the application of adobe mud to bond the individual bricks into a structure. There is no standard size, with substantial variations over the years and in different regions. In some areas a popular size measured weighing about ; in other contexts the size is weig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sana'a
Sanaa ( ar, صَنْعَاء, ' , Yemeni Arabic: ; Old South Arabian: 𐩮𐩬𐩲𐩥 ''Ṣnʿw''), also spelled Sana'a or Sana, is the capital and largest city in Yemen and the centre of Sanaa Governorate. The city is not part of the Governorate, but forms the separate administrative district of "ʾAmānat al-ʿĀṣima" (). Under the Yemeni constitution, Sanaa is the capital of the country, although the seat of the Yemeni government moved to Aden, the former capital of South Yemen in the aftermath of the Houthi occupation. Aden was declared as the temporary capital by President Abdrabbuh Mansur Hadi in March 2015. At an elevation of , Sanaa is one of the highest capital cities in the world and is next to the Sarawat Mountains of Jabal An-Nabi Shu'ayb and Jabal Tiyal, considered to be the highest mountains in the country and amongst the highest in the region. Sanaa has a population of approximately 3,937,500 (2012), making it Yemen's largest city. As of 2020, the grea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1984 Morgan Hill Earthquake
The 1984 Morgan Hill earthquake (also known as the Halls Valley earthquake) occurred on April 24 at in the Santa Clara Valley of Northern California. The shock had a moment magnitude of 6.2 and a maximum Mercalli intensity scale, Mercalli intensity of VIII (''Severe''). The epicenter was located near Mount Hamilton (California), Mount Hamilton in the Diablo Range of the California Coast Ranges. Nearby communities (including Morgan Hill, California, Morgan Hill) sustained serious damage with financial losses of at least United States dollar, US$7.5 million. Earthquake The earthquake occurred along the Calaveras Fault, with the epicenter northeast of San Jose, California, San Jose, and at a depth of . The shock was felt in Sacramento, California, Sacramento in California's central valley. Damage The earthquake was reported to be felt over an area of . Morgan Hill, California, Morgan Hill was the worst affected, with a number of mobile homes sliding off foundations, and moderate d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1983 Coalinga Earthquake
The 1983 Coalinga earthquake struck at 4:42 p.m. Monday, May 2 of that year, in Coalinga, California. The shock was felt from the Greater Los Angeles Area north to Susanville in Lassen County, and between the Pacific Coast and western Nevada. More than 5,000 aftershocks were recorded through July 31, of which 894 had a magnitude of 2.5 or larger. It measured 6.2 on the moment magnitude scale and had a maximum Mercalli intensity of VIII (''Severe''). Earthquake The Coalinga quake was caused by an 0.5-meter uplift of an anticline ridge northeast of Coalinga, but surface faulting was not observed. Ground and aerial reconnaissance immediately after the quake revealed ground cracks and fissures within about of the epicenter, none of which appeared to represent movement on deeply rooted fault structures. About five weeks later, on June 11, an aftershock caused surface faulting about northwest of Coalinga. Damage The earthquake caused an estimated $10 million in property damag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Fault
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 ... [...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 tert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Sea Rift
The Red Sea Rift is a spreading center between two tectonic plates, the African Plate and the Arabian Plate. It extends from the Dead Sea Transform fault system, and ends at an intersection with the Aden Ridge and the East African Rift, forming the Afar Triple Junction in the Afar Depression of the Horn of Africa. The Red Sea Rift was formed by the divergence between the African Plate and the Arabian Plate. The rift transitioned from a continental rift to an oceanic rift. Magnetic anomalies suggest that the spreading rate on either side of the Red Sea is about 1 cm/year. The African plate has a rotation rate of 0.9270 degrees/ Ma, while the Arabian plate has a rotation rate of 1.1616 degrees/Ma. Spreading model A two-stage spreading model explains the tectonic evolution in this region. The first major rift motion was seen in the lower/middle Eocene, followed by major seafloor spreading in the late Eocene and early Oligocene. This was followed by a period of 30 Ma of no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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