|
1703 Apennine Earthquakes
The 1703 Apennine earthquakes were a sequence of three earthquakes of magnitude ≥6 that occurred in the central Apennines of Italy, over a period of 19 days. The epicenters were near Norcia (14 January), Montereale (16 January) and L'Aquila (2 February), showing a southwards progression over about . These events involved all of the known active faults between Norcia and L'Aquila. A total of about 10,000 people are estimated to have died as a result of these earthquakes, although because of the overlap in areas affected by the three events, casualty numbers remain highly uncertain. Tectonic setting The central part of the Apennines has been characterised by extensional tectonics since the Pliocene epoch (i.e. about the last 5 million years), with most of the active faults being normal in type and NW-SE trending. The extension is due to the back-arc basin in the Tyrrhenian Sea opening faster than the African Plate is colliding with the Eurasian Plate. The Norcia earthquake The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richter Magnitude Scale
The Richter scale —also called the Richter magnitude scale, Richter's magnitude scale, and the Gutenberg–Richter scale—is a measure of the strength of earthquakes, developed by Charles Francis Richter and presented in his landmark 1935 paper, where he called it the "magnitude scale". This was later revised and renamed the local magnitude scale, denoted as ML or . Because of various shortcomings of the original scale, most seismological authorities now use other similar scales such as the moment magnitude scale () to report earthquake magnitudes, but much of the news media still erroneously refers to these as "Richter" magnitudes. All magnitude scales retain the logarithmic character of the original and are scaled to have roughly comparable numeric values (typically in the middle of the scale). Due to the variance in earthquakes, it is essential to understand the Richter scale uses logarithms simply to make the measurements manageable (i.e., a magnitude 3 quake factors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurasian Plate
The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and the area east of the Chersky Range in eastern Siberia. It also includes oceanic crust extending westward to the Mid-Atlantic Ridge and northward to the Gakkel Ridge. The eastern edge is a boundary with the North American Plate to the north and a boundary with the Philippine Sea Plate to the south and possibly with the Okhotsk Plate and the Amurian Plate. The southern edge is a boundary with the African Plate to the west, the Arabian Plate in the middle and the Indo-Australian Plate to the east. The western edge is a divergent boundary with the North American Plate forming the northernmost part of the Mid-Atlantic Ridge, which is straddled by Iceland. All volcanic eruptions in Iceland, such as the 1973 eruption of Eldfell, the 1783 eruptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2009 L'Aquila Earthquake
The 2009 L'Aquila earthquake occurred in the region of Abruzzo, in central Italy. The main shock occurred at 03:32 CEST (01:32 UTC) on 6 April 2009, and was rated 5.8 or 5.9 on the Richter magnitude scale and 6.3 on the moment magnitude scale; its epicentre was near L'Aquila, the capital of Abruzzo, which together with surrounding villages suffered the most damage. There have been several thousand foreshocks and aftershocks since December 2008, more than thirty of which had a Richter magnitude greater than 3.5. The earthquake was felt throughout central Italy; 308 people are known to have died, making this the deadliest earthquake to hit Italy since the 1980 Irpinia earthquake. In a subsequent inquiry of the handling of the disaster, seven members of the Italian National Commission for the Forecast and Prevention of Major Risks were accused of giving "inexact, incomplete and contradictory" information about the danger of the tremors prior to the main quake. On 22 October 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coulomb Stress Transfer
Coulomb stress transfer is a seismic-related geological process of stress changes to surrounding material caused by local discrete deformation events. Using mapped displacements of the Earth's surface during earthquakes, the computed Coulomb stress changes suggest that the stress relieved during an earthquake not only dissipates but can also move up and down fault segments, concentrating and promoting subsequent tremors. Importantly, Coulomb stress changes have been applied to earthquake-forecasting models that have been used to assess potential hazards related to earthquake activity. Coulomb stress change The Coulomb failure criterion requires that the Coulomb stress exceeds a value σf defined by the shear stress τB, normal stress σB, pore pressure p, and coefficient of friction μ of a failure plane, such that It is also often assumed that changes in pore fluid pressure induced by changes in stress are proportional to the normal stress change across the fault plane. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aterno
The Aterno-Pescara (ancient ''Aternus'' from the Greek ''Aternos'', ''Άτερνος'') is a river system in Abruzzo, eastern central Italy. The river is known as the Aterno near its source in the mountains, but takes the name Pescara, actually a tributary, nearer the city of Pescara and the Adriatic Sea. Having the greatest discharge basin of the rivers flowing into the Adriatic Sea south of the Reno, the Aterno has its origin in the Monti della Laga, near Montereale and Lago di Campotosto in the province of L'Aquila. The river flows in a southeastern direction past Pizzoli, L'Aquila, Paganica, San Demetrio ne' Vestini, and Castelvecchio Subequo through the Appennino Abruzzese mountains. It subsequently flows until the Valle Peligna (or Sulmona plateau) near Raiano, where it curves northward and receives its main tributary, the Sagittario. Later, near Popoli, it crosses the border into the province of Pescara and joins with the short, but large volumed, Pescara, by which name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Liquefaction
Soil liquefaction occurs when a cohesionless saturated or partially saturated soil substantially loses strength and stiffness in response to an applied stress such as shaking during an earthquake or other sudden change in stress condition, in which material that is ordinarily a solid behaves like a liquid. In soil mechanics, the term "liquefied" was first used by Allen Hazen in reference to the 1918 failure of the Calaveras Dam in California. He described the mechanism of flow liquefaction of the embankment dam as: The phenomenon is most often observed in saturated, loose (low density or uncompacted), sandy soils. This is because a loose sand has a tendency to compress when a load is applied. Dense sands, by contrast, tend to expand in volume or 'dilate'. If the soil is saturated by water, a condition that often exists when the soil is below the water table or sea level, then water fills the gaps between soil grains ('pore spaces'). In response to soil compressing, the po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posta (RI)
:''See Posta and Poşta for disambiguation.'' Posta is a ''comune'' (municipality) in the Province of Rieti in the Italian region Latium, located about northeast of Rome and about northeast of Rieti. As of 31 December 2004, it had a population of 819 and an area of .All demographics and other statistics: Italian statistical institute Istat. The municipality of Posta contains the ''frazioni'' (subdivisions, mainly villages and hamlets) Bacugno, Favischio, Figino, Fontarello, Picciame, Sigillo, Steccato and Villa Camponeschi. Posta borders the following municipalities: Borbona, Cittareale, Leonessa, Micigliano Micigliano is a ''comune'' (municipality) in the Province of Rieti in the Italian region Latium, located about northeast of Rome and about northeast of Rieti. As of 31 December 2004, it had a population of 146 and an area of .All demographics an ..., Montereale. Demographic evolution Colors= id:lightgrey value:gray(0.9) id:darkgrey value:gray(0.8) id:sfond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amatrice
Amatrice (; Sabino: ) is a town and ''comune'' in the province of Rieti, in northern Lazio (central Italy), and the center of the food-agricultural area of Gran Sasso e Monti della Laga National Park. The town was devastated by a powerful earthquake on 24 August 2016. History Archaeological discoveries show a human presence in the area of Amatrice since prehistoric times, and the remains of Roman buildings and tombs have also been found. After the fall of the Western Roman Empire, the area became part of the Lombard Duchy of Spoleto, included in the comitatus of Ascoli. The town of Matrice is mentioned in the papers of the Abbey of Farfa in 1012 as commanding the confluence of the Tronto and Castellano rivers. In the year 900 the Pope was from Amatrice. The medieval and early modern periods In 1265, during the reign of Manfred of Sicily, Amatrice became part of the Kingdom of Naples. After the capture of Naples by the Angevins, Amatrice rebelled but was vanquished by Charle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accumoli
Accumoli is a ''comune'' (municipality) in the Province of Rieti in the Italian region Lazio, located about northeast of Rome and about northeast of Rieti. It is located in the natural park known as the "Gran Sasso e Monti della Laga National Park". Located at an altitude of 855 m above sea level in the Umbria-Marche Apennines, Accumoli is an enclave within the province of Ascoli Piceno. Until 1927, it was part of the province of Aquila in Abruzzo. The climate is typical internal Apennines with cold, snowy winters and summers almost never too hot. History The town has its origins in the 12th century, when the territory in the Valle del Tronto was ruled by the Normans and later the Kingdom of Naples. On 24 August 2016, numerous buildings were destroyed and damaged by the Central Italy earthquake. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cittareale
Cittareale is a ''comune'' (municipality) in the Province of Rieti in the Italian region Latium. It is located about northeast of Rome and northeast of Rieti. Cittareale borders the following municipalities: Accumoli, Amatrice, Borbona, Cascia, Leonessa, Montereale, Norcia, Posta. The source of the Velino river are in the communal territory. Cittareal is home to a large Rocca (castle), which had a strategical importance due to its position between the Kingdom of Naples and the Papal States. Its current appearance date to the reconstruction by the Aragonese in 1479. The church of St. Peter in Vetozza was built over a pre-existing temple dedicated to Vacuna, and later was owned by the Abbey of Farfa. The Roman emperor Vespasian Vespasian (; la, Vespasianus ; 17 November AD 9 – 23/24 June 79) was a Roman emperor who reigned from AD 69 to 79. The fourth and last emperor who reigned in the Year of the Four Emperors, he founded the Flavian dynasty that ruled the Emp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Rupture
In seismology, surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a fault affects the Earth's surface. Surface rupture is opposed by buried rupture, where there is no displacement at ground level. This is a major risk to any structure that is built across a fault zone that may be active, in addition to any risk from ground shaking. Surface rupture entails vertical or horizontal movement, on either side of a ruptured fault. Surface rupture can affect large areas of land. __TOC__ Lack of surface rupture Not every earthquake results in surface rupture, particularly for smaller and deeper earthquakes. In some cases, however, the lack of surface effects is because the fault that moved does not reach the surface. For example, the 1994 Northridge earthquake had a moment magnitude of 6.7, caused major damage in the Los Angeles area, occurred at below the Earth's surface, but did not cause surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercalli Intensity Scale
The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the effects of an earthquake at a given location, distinguished from the earthquake's inherent force or strength as measured by seismic magnitude scales (such as the "" magnitude usually reported for an earthquake). While shaking is caused by the seismic energy released by an earthquake, earthquakes differ in how much of their energy is radiated as seismic waves. Deeper earthquakes also have less interaction with the surface, and their energy is spread out across a larger volume. Shaking intensity is localized, generally diminishing with distance from the earthquake's epicenter, but can be amplified in sedimentary basins and certain kinds of unconsolidated soils. Intensity scales empirically categorize the intensity of shaking based on the effect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
