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1904 Kresna Earthquakes
The 1904 Kresna earthquakes occurred on the same day of April 4 in the Ottoman Empire (present-day Bulgaria). The pair of earthquakes measured 6.9 and 7.2 on the surface wave magnitude scale, and were assigned the respective Modified Mercalli intensity scale ratings of X (''Extreme'') and XI (''Extreme''). More than 200 people were killed in the two earthquakes. Several villages were obliterated as a result. Earthquakes The first shock occurred in the morning of April 4 at 11:58 local time. It had an epicenter located Struma (river), Struma River Valley between the then villages Kresna Municipality, Kresna and Krupnik, Blagoevgrad Province, Krupnik. A larger mainshock occurred approximately 20 minutes later. The two earthquakes resulted in the total destruction of Simitli and Krupnik, Blagoevgrad Province, Krupnik. Major damage occurred in the towns of Blagoevgrad, Dzhumaya, Bansko and Razlog. The two quakes caused more than 200 deaths in its aftermath. According to survivors of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulgaria
Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedonia to the west, Greece and Turkey to the south, and the Black Sea to the east. Bulgaria covers a territory of , and is the sixteenth-largest country in Europe. Sofia is the nation's capital and largest city; other major cities are Plovdiv, Varna and Burgas. One of the earliest societies in the lands of modern-day Bulgaria was the Neolithic Karanovo culture, which dates back to 6,500 BC. In the 6th to 3rd century BC the region was a battleground for ancient Thracians, Persians, Celts and Macedonians; stability came when the Roman Empire conquered the region in AD 45. After the Roman state splintered, tribal invasions in the region resumed. Around the 6th century, these territories were settled by the early Slavs. The Bulgars, led by Asp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fissure
A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word , which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes. Ground fissure A , also called an , is a long, narrow crack or linear opening in the Earth's crust. Ground fissures can form naturally, such as from tectonic faulting and earthquakes, or as a consequence of human activity, such as oil mining and groundwater pumping. Once formed, ground fissures can be extended and eroded by torrential rain. They can be hazardous to people and livestock living on the affected surfaces and damaging to property and infrastructure, such as roads, underground pipes, canals, and dams. In circumstances where there is the extensive withdrawal of groundwater, the earth above the water table can subside causing fissures to form at the surface. This typically occurs at the floor of arid valleys having rock formations and compacte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kresna Gorge
Kresna Gorge ( bg, Кресненско дефиле) is a steep valley in south-western Bulgaria, stretching about 18 km. The gorge has been formed by the Struma River, which flows from the Vitosha mountains. Kresna gorge has a rich biodiversity, which has come under pressure from the Struma motorway construction project, a new leg of the Trans European Corridor No. 4. In the south, the gorge bisects the Tisata nature reserve. Kresna Gorge was the place of the Battle of Kresna Gorge between Bulgaria and Greece during the 1913 Second Balkan War. The Greek army was threatened by encirclement in the valley, but due to the Romanian army advancing against the undefended capital Sofia, Bulgaria had to agree to an armistice and the resulting peace treaty in Bucharest which was unfavorable to Bulgaria's territorial aspirations. Terrain and Climate Kresna Gorge is situated near the villages of Palat, Drakata, and Krupnik while surrounded by the Pirin and Maleshevska Mountains. The gorg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Cave
A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea caves, rock shelters, and grottos, that extend a relatively short distance into the rock and they are called ''exogene'' caves. Caves which extend further underground than the opening is wide are called ''endogene'' caves. Speleology is the science of exploration and study of all aspects of caves and the cave environment. Visiting or exploring caves for recreation may be called ''caving'', ''potholing'', or ''spelunking''. Formation types The formation and development of caves is known as ''speleogenesis''; it can occur over the course of millions of years. Caves can range widely in size, and are formed by various geological processes. These may involve a combination of chemical processes, erosion by water, tectonic forces, microorganisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitude
Longitude (, ) is a geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians are semicircular lines running from pole to pole that connect points with the same longitude. The prime meridian defines 0° longitude; by convention the International Reference Meridian for the Earth passes near the Royal Observatory in Greenwich, England on the island of Great Britain. Positive longitudes are east of the prime meridian, and negative ones are west. Because of the Earth's rotation, there is a close connection between longitude and time measurement. Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absolute measure of time allows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pole, with 0° at the Equator. Lines of constant latitude, or ''parallels'', run east–west as circles parallel to the equator. Latitude and ''longitude'' are used together as a coordinate pair to specify a location on the surface of the Earth. On its own, the term "latitude" normally refers to the ''geodetic latitude'' as defined below. Briefly, the geodetic latitude of a point is the angle formed between the vector perpendicular (or ''normal'') to the ellipsoidal surface from the point, and the plane of the equator. Background Two levels of abstraction are employed in the definitions of latitude and longitude. In the first step the physical surface is modeled by the geoid, a surface which approximates the mean sea level over the ocean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Francis Richter
Charles Francis Richter (; April 26, 1900 – September 30, 1985) was an American seismologist and physicist. Richter is most famous as the creator of the Richter magnitude scale, which, until the development of the moment magnitude scale in 1979, quantified the size of earthquakes. Inspired by Kiyoo Wadati's 1928 paper on shallow and deep earthquakes, Richter first used the scale in 1935 after developing it in collaboration with Beno Gutenberg; both worked at the California Institute of Technology. The quote " logarithmic plots are a device of the devil" is attributed to Richter. Childhood and education Richter was born in Overpeck, Ohio. Richter had German heritage: his great-grandfather was a Forty-Eighter, coming from Baden-Baden (today in Baden-Württemberg, Germany) in 1848 in the wake of the Revolutions of 1848 in the German states. Richter's parents Frederick William and Lillian Anna (Kinsinger) Richter, were divorced when he was very young. He grew up with his materna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beno Gutenberg
Beno Gutenberg (; June 4, 1889 – January 25, 1960) was a German-American seismologist who made several important contributions to the science. He was a colleague and mentor of Charles Francis Richter at the California Institute of Technology and Richter's collaborator in developing the Richter magnitude scale for measuring an earthquake's magnitude. Early life, family and education Gutenberg was born in Darmstadt, Germany. His father owned a factory. He obtained his doctorate in physics from the University of Göttingen in 1911. His advisor was Emil Wiechert. Career During World War I, Gutenberg served in the German Army as a meteorologist in support of gas warfare operations. Gutenberg held positions at the University of Strasbourg, which he lost when Strasbourg became French in 1918. After some years during which he had to sustain himself with managing his father's soap factory, he obtained in 1926 a junior professorship at University of Frankfurt-am-Main, which was ... [...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] |
Fault Scarp
A fault scarp is a small step or offset on the ground surface where one side of a fault has moved vertically with respect to the other. It is the topographic expression of faulting attributed to the displacement of the land surface by movement along faults. They are exhibited either by differential movement and subsequent erosion along an old ''inactive'' geologic fault (a sort of old rupture), or by a movement on a recent active fault. Characteristics Fault scarps often contain highly fractured rock of both hard and weak consistency. In many cases, bluffs form from the upthrown block and can be very steep. The height of the scarp formation is equal to the vertical displacement along the fault. Active scarps are usually formed by tectonic displacement, e.g. when an earthquake changes the elevation of the ground and can be caused by any type of fault, including strike-slip faults, whose motion is primarily horizontal. This movement is usually episodic, with the height of the bluf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Survey
Field research, field studies, or fieldwork is the collection of raw data outside a laboratory, library, or workplace setting. The approaches and methods used in field research vary across disciplines. For example, biologists who conduct field research may simply observe animals interacting with their environments, whereas social scientists conducting field research may interview or observe people in their natural environments to learn their languages, folklore, and social structures. Field research involves a range of well-defined, although variable, methods: informal interviews, direct observation, participation in the life of the group, collective discussions, analyses of personal documents produced within the group, self-analysis, results from activities undertaken off- or on-line, and life-histories. Although the method generally is characterized as qualitative research, it may (and often does) include quantitative dimensions. History Field research has a long history ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoseismal Map
In seismology, an isoseismal map is used to show lines of equally felt seismic intensity, generally measured on the Modified Mercalli scale. Such maps help to identify earthquake epicenters, particularly where no instrumental records exist, such as for historical earthquakes. They also contain important information on ground conditions at particular locations, the underlying geology, radiation pattern of the seismic waves, and the response of different types of buildings. They form an important part of the macroseismic approach, i.e. that part of seismology dealing with noninstrumental data. The shape and size of the isoseismal regions can be used to help determine the magnitude, focal depth, and focal mechanism of an earthquake. History The first known isoseismal map was produced for the 1810 earthquake in Mór in Hungary, and published by Kitaibel and Tomtsányi in 1814. The first, six-level intensity scale was proposed by Egen in 1828 for an earthquake in Rhineland. Robert M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
