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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; are usually seismically inactive (because both plate segments are moving in the same direction), although they can display evidence of 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. They can be associated with other tectonic features and may be subducted or distorted by later tectonic activity. They are usually defined with bathymetric, gravity and magneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Map Data/Fracture Zone
A map is a symbolic depiction of interrelationships, commonly spatial, between things within a space. A map may be annotated with text and graphics. Like any graphic, a map may be fixed to paper or other durable media, or may be displayed on a transitory medium such as a computer screen. Some maps change interactively. Although maps are commonly used to depict geography, geographic elements, they may represent any space, real or fictional. The subject being mapped may be two-dimensional such as Earth's surface, three-dimensional such as Earth's interior, or from an abstract space of any dimension. Maps of geographic territory have a very long tradition and have existed from ancient times. The word "map" comes from the , wherein ''mappa'' meant 'napkin' or 'cloth' and ''mundi'' 'of the world'. Thus, "map" became a shortened term referring to a flat representation of Earth's surface. History Maps have been one of the most important human inventions for millennia, allowin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strike Slip 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 geological 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] |
South Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for separating the New World of the Americas (North America and South America) from the Old World of Afro-Eurasia (Africa, Asia, and Europe). Through its separation of Afro-Eurasia from the Americas, the Atlantic Ocean has played a central role in the development of human society, globalization, and the histories of many nations. While the Norse colonization of North America, Norse were the first known humans to cross the Atlantic, it was the expedition of Christopher Columbus in 1492 that proved to be the most consequential. Columbus's expedition ushered in an Age of Discovery, age of exploration and colonization of the Americas by European powers, most notably Portuguese Empire, Portugal, Spanish Empire, Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Atlantic
The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for separating the New World of the Americas (North America and South America) from the Old World of Afro-Eurasia (Africa, Asia, and Europe). Through its separation of Afro-Eurasia from the Americas, the Atlantic Ocean has played a central role in the development of human society, globalization, and the histories of many nations. While the Norse were the first known humans to cross the Atlantic, it was the expedition of Christopher Columbus in 1492 that proved to be the most consequential. Columbus's expedition ushered in an age of exploration and colonization of the Americas by European powers, most notably Portugal, Spain, France, and the United Kingdom. From the 16th to 19th centuries, the Atlantic Ocean was the center of both an epo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gorda Plate
The Gorda plate, located beneath the Pacific Ocean off the coast of northern California, is one of the northern remnants of the Farallon plate. It is sometimes referred to (by, for example, publications from the USGS Earthquake Hazards Program) as simply the southernmost portion of the neighboring Juan de Fuca plate, another Farallon remnant. Unlike most tectonic plates, the Gorda plate experiences significant intraplate deformation inside its boundaries. Numerous faults have been mapped in both the sediments and basement of the Gorda Basin, which is in the interior of the plate south of 41.6°N. Stresses from the neighboring North American plate and Pacific plate cause frequent earthquakes in the interior of the plate, including the 1980 Eureka earthquake (also known as the Gorda Basin event). The easterly side is the Cascadia subduction zone where the plate subducts under the North American plate in northern California. The southerly side is a transform boundary with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendocino Fracture Zone
The Mendocino fracture zone is a fracture zone and transform boundary over 4000 km (2500 miles) long, starting off the coast of Cape Mendocino in far northern California. It runs westward from a triple junction with the San Andreas Fault and the Cascadia subduction zone for about 300 km to the southern end of the Gorda Ridge. It continues on west of its junction with the Gorda Ridge, as an inactive remnant section which extends for about 4,000 km to approximately 35°N 175°W. Technically, a fracture zone is not a transform fault, but in the case of the Mendocino, the term has been loosely applied to the active fault segment east of the Gorda Ridge as well as to the true fracture zone segment west of it. Many seismologists refer to the active segment as the Mendocino Fault or Mendocino fault zone. The fault section demarcates the boundary between the northwestward-moving Pacific plate and the eastward-moving Gorda plate. The Gorda plate is subducting beneath the No ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Pacific Rise
The East Pacific Rise (EPR) is a mid-ocean rise (usually 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), at 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 , where it joins the Pacific-Antarctic Ridge (PAR) trending west-south-west 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 off the South American coast and reaches a height about above the surrounding seafloor. Overview The oceanic crust is moving away from the East Pacific Rise to either side. Near Easter Island th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific–Antarctic Ridge
The Pacific-Antarctic Ridge (PAR, Antarctic Pacific Ridge, South Pacific Rise, South Pacific Ridge) is a divergent tectonic plate boundary located on the seafloor of the South Pacific Ocean, separating the Pacific plate from the Antarctic plate. It is regarded as the southern section of the East Pacific Rise in some usages, generally south of the Challenger fracture zone which is associated with a triple junction between the Juan Fernández microplate, the Pacific plate and the Antarctic plate. It stretches from there in a general southwesterly direction to the Macquarie Triple Junction south of New Zealand. Tectonics The divergence rate between the two plates along the ridge is believed to vary from about near 65°S to near the Udintsev fracture zone at 55°S. This area of transition in sea floor spreading rate has been mapped by multiple techniques and occurs near the Heirtzler fracture zone. The ridge is related to the Late Cretaceous breakup of Gondwana. To the so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advisory Committee On Undersea Features
Advisory may refer to: * Advisory board, a body that provides advice to the management of a corporation, organization, or foundation * Boil-water advisory, a public health directive given by government to consumers when a community's drinking water could be contaminated by pathogens * Homeroom, or advisory, is the classroom session in which a teacher records attendance and makes announcements * Significant weather advisory, a Special Weather Statement advising inclement weather is likely or imminent See also * Advice (other) Advice (noun) or advise (verb) may refer to: * Advice (opinion), an opinion or recommendation offered as a guide to action, conduct * Advice (constitutional law) a frequently binding instruction issued to a constitutional office-holder * Advice ... * Advisory Council (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetostratigraphy
Magnetostratigraphy is a geophysical correlation technique used to date sedimentary and volcanic sequences. The method works by collecting oriented samples at measured intervals throughout the section. The samples are analyzed to determine their ''characteristic remanent magnetization'' (ChRM), that is, the polarity of Earth's magnetic field at the time a stratum was deposited. This is possible because volcanic flows acquire a thermoremanent magnetization and sediments acquire a depositional remanent magnetization, both of which reflect the direction of the Earth's field at the time of formation. This technique is typically used to date sequences that generally lack fossils or interbedded igneous rock. It is particularly useful in high-resolution correlation of deep marine stratigraphy where it allowed the validation of the Vine–Matthews–Morley hypothesis related to the theory of plate tectonics. Technique When measurable magnetic properties of rocks vary stratigraphically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heirtzler Fracture Zone
The Heirtzler fracture zone is an undersea fracture zone located south of New Zealand, near Antarctica, that has been estimated to have been a propagator region of the Pacific–Antarctic Ridge for 5–6 million years. The presumed seismically and tectonically active portion of this fracture zone is known as the Heirtzler transform fault and divides a portion of the Pacific-Antarctic Ridge where spreading rates increase towards its axial north from /year over a distance of . The Heirtzler transform fault portion has areas of gravity highs, and as well as its larger propagating region, it has to the southeast a smaller Pacific-Antarctic Ridge propagator that may have started about one million years ago, with both associated with clockwise changes in spreading direction. The feature was named for James R. Heirtzler, a geophysicist who was a pioneer in geomagnetics studies. The name was proposed by the Lamont–Doherty Geological Observatory (now the Lamont–Doherty Earth O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
