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Panama Fracture Zone
The Panama Fracture Zone is a major, active right lateral-moving transform fault and associated inactive fracture zone which forms part of the tectonic boundary between the Cocos Plate and the Nazca Plate. It is part of the triple junction between the Cocos Plate, Nazca Plate and Caribbean Plate which is moving in the southeastern direction at 5.5 cm/yr. It runs from the East Pacific Rise to the Middle America Trench The Middle America Trench is a major subduction zone, an oceanic trench in the eastern Pacific Ocean off the southwestern coast of Middle America, stretching from central Mexico to Costa Rica. The trench is 1,700 miles (2,750 km) long an .... References * * Fracture zones Geology of Panama {{tectonics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transform Fault
A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subduction zone. A transform fault is a special case of a ''strike-slip fault'' that also forms a plate boundary. Most such faults are found in oceanic crust, where they accommodate the lateral offset between segments of divergent boundaries, forming a zigzag pattern. This is a result of oblique seafloor spreading where the direction of motion is not perpendicular to the trend of the overall divergent boundary. A smaller number of such faults are found on land, although these are generally better-known, such as the San Andreas Fault and North Anatolian Fault. Nomenclature Transform boundaries are also known as conservative plate boundaries because they involve no addition or loss of lithosphere at the Earth's surface. Background Geophysicist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture Zone
A fracture zone is a linear feature on the ocean floor—often hundreds, even thousands of kilometers long—resulting from the action of offset mid-ocean ridge axis segments. They are a consequence of plate tectonics. Lithospheric plates on either side of an active transform fault move in opposite directions; here, strike-slip activity occurs. Fracture zones extend past the transform faults, away from the ridge axis; seismically inactive (because both plate segments are moving in the same direction), they display evidence of past transform fault activity, primarily in the different ages of the crust on opposite sides of the zone. In actual usage, many transform faults aligned with fracture zones are often loosely referred to as "fracture zones" although technically, they are not. Structure and formation Mid-ocean ridges are divergent plate boundaries. As the plates on either side of an offset mid-ocean ridge move, a transform fault forms at the offset between the two ridges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocos Plate
The Cocos Plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate broke into two pieces, which also created the Nazca Plate. The Cocos Plate also broke into two pieces, creating the small Rivera Plate. The Cocos Plate is bounded by several different plates. To the northeast it is bounded by the North American Plate and the Caribbean Plate. To the west it is bounded by the Pacific Plate and to the south by the Nazca Plate. __TOC__ Geology The Cocos Plate was created by sea floor spreading along the East Pacific Rise and the Cocos Ridge, specifically in a complicated area geologists call the Cocos-Nazca spreading system. From the rise the plate is pushed eastward and pushed or dragged (perhaps both) under the less dense Caribbean Plate, in the process called subduction. The subducted leading edge heats ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nazca Plate
The Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the Nazca Plate under the South American Plate is largely responsible for the Andean orogeny. The Nazca Plate is bounded on the west by the Pacific Plate and to the south by the Antarctic Plate through the East Pacific Rise and the Chile Rise respectively. The movement of the Nazca Plate over several hotspots has created some volcanic islands as well as east-west running seamount chains that subduct under South America. Nazca is a relatively young plate both in terms of the age of its rocks and its existence as an independent plate having been formed from the break-up of the Farallon Plate about 23 million years ago. The oldest rocks of the plate are about 50 million years old. Boundaries East Pacific and Chile Rise A triple junctio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triple Junction
A triple junction is the point where the boundaries of three tectonic plates meet. At the triple junction each of the three boundaries will be one of three types – a ridge (R), trench (T) or transform fault (F) – and triple junctions can be described according to the types of plate margin that meet at them (e.g. Fault-Fault-Trench, Ridge-Ridge-Ridge, or abbreviated F-F-T, R-R-R). Of the ten possible types of triple junction only a few are stable through time ('stable' in this context means that the geometrical configuration of the triple junction will not change through geologic time). The meeting of four or more plates is also theoretically possible but junctions will only exist instantaneously. History The first scientific paper detailing the triple junction concept was published in 1969 by Dan McKenzie and W. Jason Morgan. The term had traditionally been used for the intersection of three divergent boundaries or spreading ridges. These three divergent boundaries ideally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caribbean Plate
The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America. Roughly 3.2 million square kilometers (1.2 million square miles) in area, the Caribbean Plate borders the North American Plate, the South American Plate, the Nazca Plate and the Cocos Plate. These borders are regions of intense seismic activity, including frequent earthquakes, occasional tsunamis, and volcanic eruptions. Boundary types The northern boundary with the North American Plate is a transform or strike-slip boundary which runs from the border area of Belize, Guatemala (Motagua Fault), and Honduras in Central America, eastward through the Cayman trough along the Swan Islands Transform Fault before joining the southern boundary of the Gonâve Microplate. East of the Mid-Cayman Rise this continues as the Walton fault zone and the Enriquillo–Plantain Garden fault zone into eastern Hispaniola. From there it continues into Puerto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Pacific Rise
The East Pacific Rise is a mid-ocean rise (termed an oceanic rise and not a mid-ocean ridge due to its higher rate of spreading that results in less elevation increase and more regular terrain), a divergent tectonic plate boundary located along the floor of the Pacific Ocean. It separates the Pacific Plate to the west from (north to south) the North American Plate, the Rivera Plate, the Cocos Plate, the Nazca Plate, and the Antarctic Plate. It runs south from the Gulf of California in the Salton Sea basin in Southern California to a point near 55° S, 130° W, where it joins the Pacific-Antarctic Ridge trending west-southwest towards Antarctica, near New Zealand (though in some uses the PAR is regarded as the southern section of the EPR). Much of the rise lies about 3200 km (2000 mi) off the South American coast and rises about 1,800–2,700 m (6,000–9,000 ft) above the surrounding seafloor. Overview The oceanic crust is moving away from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle America Trench
The Middle America Trench is a major subduction zone, an oceanic trench in the eastern Pacific Ocean off the southwestern coast of Middle America, stretching from central Mexico to Costa Rica. The trench is 1,700 miles (2,750 km) long and is 21,880 feet (6,669 m) at its deepest point. The trench is the boundary between the Rivera, Cocos, and Nazca plates on one side and the North American and Caribbean plates on the other. It is the 18th-deepest trench in the world. Many large earthquakes have occurred in the area of the Middle America Trench. Division The Middle America Trench can be divided into a northern and a southern section. The division, however, is not the same in its seaward side and its landward side. In the seaward side, the northern section, called the Acapulco Trench, runs from Jalisco to the Tehuantepec Ridge, and the southern section, called the Guatemala Trench, runs from the Tehuantepec Ridge to the Cocos Ridge. On the landward side, the division is dem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture Zones
Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displacement develops perpendicular to the surface, it is called a normal tensile crack or simply a crack; if a displacement develops tangentially, it is called a shear crack, slip band or dislocation. Brittle fractures occur with no apparent deformation before fracture. Ductile fractures occur after visible deformation. Fracture strength, or breaking strength, is the stress when a specimen fails or fractures. The detailed understanding of how a fracture occurs and develops in materials is the object of fracture mechanics. Strength Fracture strength, also known as breaking strength, is the stress at which a specimen fails via fracture. This is usually determined for a given specimen by a tensile test, which charts the stress–strain c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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