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Apsheron Threshold
The Apsheron Sill, Absheron Sill, Apsheron Ridge or Apsheron Threshold is a major northwest–southeast trending bathymetric high that runs for about 250 km across the whole of the Caspian Sea from Baku in Azerbaijan to the Cheleken Peninsula in Turkmenistan. The sill separates the central and southern parts of the Caspian Sea. It is interpreted to be the surface expression of a northeast- dipping subduction zone along which oceanic crust of the South Caspian Basin is being subducted beneath the Central Caspian as part of the complex zone of continental collision between the Arabian Plate and the 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 .... References {{Reflist Caspian Sea Geology of Azerbaijan Geology of Turkmenistan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathymetry
Bathymetry (; ) is the study of underwater depth of ocean floors (''seabed topography''), lake floors, or river floors. In other words, bathymetry is the underwater equivalent to hypsometry or topography. The first recorded evidence of water depth measurements are from Ancient Egypt over 3000 years ago. Bathymetric (or hydrographic) charts are typically produced to support safety of surface or sub-surface navigation, and usually show seafloor relief or terrain as contour lines (called depth contours or isobaths) and selected depths ('' soundings''), and typically also provide surface navigational information. Bathymetric maps (a more general term where navigational safety is not a concern) may also use a Digital Terrain Model and artificial illumination techniques to illustrate the depths being portrayed. The global bathymetry is sometimes combined with topography data to yield a global relief model. Paleobathymetry is the study of past underwater depths. Seabed topography ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspian Sea
The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia, south of the fertile plains of Southern Russia in Eastern Europe, and north of the mountainous Iranian Plateau of Western Asia. It covers a surface area of (excluding the highly saline lagoon of Garabogazköl to its east) and a volume of . It has a salinity of approximately 1.2% (12 g/L), about a third of the salinity of average seawater. It is bounded by Kazakhstan to the northeast, Russia to the northwest, Azerbaijan to the southwest, Iran to the south, and Turkmenistan to the southeast. The sea stretches nearly from north to south, with an average width of . Its gross coverage is and the surface is about below sea level. Its main freshwater inflow, Europe's longest river, the Volga, enters at the shallow north end. Two deep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baku
Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world and also the largest city in the world located below sea level. Baku lies on the southern shore of the Absheron Peninsula, alongside the Bay of Baku. Baku's urban population was estimated at two million people as of 2009. Baku is the primate city of Azerbaijan—it is the sole metropolis in the country, and about 25% of all inhabitants of the country live in Baku's metropolitan area. Baku is divided into twelve administrative raions and 48 townships. Among these are the townships on the islands of the Baku Archipelago, and the town of Oil Rocks built on stilts in the Caspian Sea, away from Baku. The Inner City of Baku, along with the Shirvanshah's Palace and Maiden Tower, were inscribed as a UNESCO World Heritage Site in 2000. The c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azerbaijan
Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of the South Caucasus region and is bounded by the Caspian Sea to the east, Russia (Republic of Dagestan) to the north, Georgia to the northwest, Armenia and Turkey to the west, and Iran to the south. Baku is the capital and largest city. The Azerbaijan Democratic Republic proclaimed its independence from the Transcaucasian Democratic Federative Republic in 1918 and became the first secular democratic Muslim-majority state. In 1920, the country was incorporated into the Soviet Union as the Azerbaijan SSR. The modern Republic of Azerbaijan proclaimed its independence on 30 August 1991, shortly before the dissolution of the Soviet Union in the same year. In September 1991, the ethnic Armenian majority of the Nagorno-Karabakh region formed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheleken Peninsula
The Cheleken Peninsula (russian: Челекен полуостров) is a peninsula located in western Turkmenistan, in the eastern shores of the Caspian Sea. The city of Hazar, former Cheleken, is located in the peninsula, which belongs administratively to Turkmenistan's Balkan Province. Geography The Cheleken Peninsula is about 40 km long and 22 km wide. It borders on the Caspian Sea in the west and with the Türkmenbaşy Gulf (former Krasnovodsk Bay) in the north. The peninsula has a continental dry climate with a precipitation of 150 mm/year. The area is desert and the central part is elevated terrain averaging 100 m elevation, with 25 m high cliffs in the central part of the western shore, while the eastern shore is low and sandy. The Peninsula has two spits or bars at the end running meridionally from north to south; the northern or right spit is also known as the Kafaldja Peninsula, while the southern or left spit running towards Ogurja Ada (Ogurchinsky Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turkmenistan
Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the south and southwest and the Caspian Sea to the west. Ashgabat is the capital and largest city. The population is about 6 million, the lowest of the Central Asian republics, and Turkmenistan is one of the most sparsely populated nations in Asia. Turkmenistan has long served as a thoroughfare for other nations and cultures. Merv is one of the oldest oasis-cities in Central Asia, and was once the biggest city in the world. It was also one of the great cities of the Islamic world and an important stop on the Silk Road. Annexed by the Russian Empire in 1881, Turkmenistan figured prominently in the anti-Bolshevik movement in Central Asia. In 1925, Turkmenistan became a constituent republic of the Soviet Union, the Turkmen Soviet Socialist Repu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Sill
An aquatic sill (or an oceanic sill) is a sea floor barrier of relatively shallow depth (tens to hundreds of meters) that restricts water movement between benthic zones of an oceanic basin or lake bottom. There are roughly 400 sills in the Earth's oceans, covering 0.01% of the seafloor. A classic example is the Strait of Gibraltar Gateway between the Mediterranean sea and the Atlantic Ocean. Formation processes Aquatic sills are common in fjords, limiting their water exchange with the ocean. After the last ice age, approximately 18,000 years ago, continental glaciers extended to the continental shelves and created U-shaped glacial valleys, with long narrow openings that rise upward near the outer shelf, thereby creating sills. Aquatic sills as barriers Circulation barriers Aquatic sills can influence water circulation by restricting the movement of bottom water masses, resulting in partial to total separation of two basins. The restricted water circulation affects tempo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strike And Dip
Strike and dip is a measurement convention used to describe the orientation, or attitude, of a planar geologic feature. A feature's strike is the azimuth of an imagined horizontal line across the plane, and its dip is the angle of inclination measured downward from horizontal. They are used together to measure and document a structure's characteristics for study or for use on a geologic map. A feature's orientation can also be represented by dip and dip direction, using the azimuth of the dip rather than the strike value. Linear features are similarly measured with trend and plunge, where "trend" is analogous to dip direction and "plunge" is the dip angle. Strike and dip are measured using a compass and a clinometer. A compass is used to measure the feature's strike by holding the compass horizontally against the feature. A clinometer measures the features dip by recording the inclination perpendicular to the strike. These can be done separately, or together using a tool such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Crust
Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumulates. The crust overlies the rigid uppermost layer of the mantle. The crust and the rigid upper mantle layer together constitute oceanic lithosphere. Oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and magnesium. It is thinner than continental crust, or sial, generally less than 10 kilometers thick; however, it is denser, having a mean density of about 3.0 grams per cubic centimeter as opposed to continental crust which has a density of about 2.7 grams per cubic centimeter. The crust uppermost is the result of the cooling of magma derived from mantle material below the plate. The magma is injected into the spreading center, which consists mainly of a partly solidified crystal mush derived from earlier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Collision
In geology, continental collision is a phenomenon of plate tectonics that occurs at convergent boundaries. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroyed, mountains produced, and two continents sutured together. Continental collision is only known to occur on Earth. Continental collision is not an instantaneous event, but may take several tens of millions of years before the faulting and folding caused by collisions stops. The collision between India and Asia has been going on for about 50 million years already and shows no signs of abating. Collision between East and West Gondwana to form the East African Orogen took about 100 million years from beginning (610 Ma) to end (510 Ma). The collision between Gondwana and Laurasia to form Pangea occurred in a relatively brief interval, about 50 million years long. Subduction zone: the collision site The process begins as two conti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabian Plate
The Arabian Plate is a minor tectonic plate in the Northern and Eastern Hemispheres. It is one of the three continental plates (along with the African and the Indian Plates) that have been moving northward in geological history and colliding with the Eurasian Plate. That is resulting in a mingling of plate pieces and mountain ranges extending in the west from the Pyrenees, crossing Southern Europe to Iran, forming the Alborz and the Zagros Mountains, to the Himalayas and ranges of Southeast Asia. Lexicology The ''Arabian Plate'' is a designation of the region, and it is also sometimes referred to as the ''Arab Plate''. Borders The Arabian Plate consists mostly of the Arabian Peninsula; it extends westward to the Sinai Peninsula and the Red Sea and northward to the Levant. The plate borders are: *East, with the Indian Plate, at the Owen Fracture Zone *South, with the African Plate to the west and the Somali Plate and the Indian Plate to the east *West, a left lateral fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
