The Nacza plate, shown in light blue

The Nazca 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. Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... For the tectonic plate, see Nazca Plate. ... The tectonic plates of the world were mapped in the second half of the 20th century. ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ...

The eastern margin is a convergent boundary subduction zone under the South American Plate and the Andes Mountains, forming the Peru-Chile Trench. The southern side is a divergent boundary with the Antarctic Plate, the Chile Rise, where seafloor spreading permits magma to rise. The western side is a divergent boundary with the Pacific Plate, forming the East Pacific Rise. The northern side is a divergent boundary with the Cocos Plate, the Galapagos Rise. A triple junction occurs at the northwest corner of the plate where the Nazca, the Cocos, and the Pacific plates all join off the coast of Colombia. A second triple junction occurs at the southwest corner at the intersection with the Nazca, the Pacific, and the Antarctic plates off the coast of southern Chile. At each of these triple junctions an anomalous microplate exists, the Galapagos Microplate at the northern junction and the Juan Fernandez Microplate at the southern junction. The Easter Island Microplate is a third microplate that is located just north of the Juan Fernandez Microplate and lies just west of Easter Island. In plate tectonics, a convergent boundary (convergent fault boundary, convergent plate boundary, or active margin) is where two tectonic plates slide towards each other and usually collide forming either a subduction zone with its associated island arc or an orogenic belt and associated mountain range. ... Categories: Geology stubs | Plate tectonics ...  The South American plate, shown in purple The South American Plate is a tectonic plate covering the continent of South America and extending eastward to the Mid-Atlantic Ridge. ... See also architecture with non-sequential dynamic execution scheduling (ANDES). ... The Peru-Chile Trench, also called Atacama Trench, is a submarine trench in the eastern Pacific Ocean, about 100 miles (160 km) off the coast of Peru and Chile. ... In plate tectonics, a divergent boundary (divergent fault boundary or divergent plate boundary), (but also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. ... The Antarctic plate is shown in blue on this map The Antarctic Plate is a continental tectonic plate covering the continent of Antarctica and extending outward under the surrounding oceans. ... The Chile Rise is an oceanic ridge at the boundary between the Nazca and Antarctic Plates. ... Age of oceanic crust. ... Magma is molten rock located beneath the surface of the Earth (or any other terrestrial planet), and which often collects in a magma chamber. ... In plate tectonics, a divergent boundary (divergent fault boundary or divergent plate boundary), (but also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. ...  The Pacific plate, shown in pale yellow The Pacific Plate is an oceanic tectonic plate beneath the Pacific Ocean. ... The East Pacific Rise is a long north-south welt of seafloor spreading under the eastern Pacific Ocean from near Antarctica in the south northward to its termination at the northern end of the Gulf of California in the Salton Sea basin in southern Pennsylvania California. ...  The Cocos plate, shown in gray-blue, off the Pacific coast of Central America The Cocos Plate (Chocos Plate) is an oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. ... The Galapagos Rise is a divergent boundary located near the triple junction of the Nazca Plate, the Cocos Plate, and the South American Plate. ... A triple junction is the point where three tectonic plates diverge. ... Rapa Nui redirects here. ...

Yet another triple junction occurs where the Nazca, Antarctic and South American plates meet. This triple junction has been considered to be related to the moment magnitude 9.5, 1960 megathrust earthquake known as the Great Chilean Earthquake. The moment magnitude scale (a successor to the Richter Scale), was introduced in 1979 by Tom Hanks and Hiroo Kanamori and is used by seismologists to compare the energy released by earthquakes. ... A megathrust earthquake is an interplate earthquake where one tectonic plate slips beneath (subducts) another. ... Map showing the areas affected by the tsunami The Great Chilean Earthquake or Valdivian Earthquake (Terremoto de Valdivia in Spanish) of 22 May 1960 is the most intense earthquake ever recorded, rating a 9. ...

Luckily, very few islands are there to suffer the earthquakes that are a result of complicated movements at these junctions. Juan Fernández Islands is an exception. The town of San Juan Bautista in Cumberland Bay, Robinson Crusoe Island The Juan Fernández Islands is a sparsely inhabited island group reliant on tourism in the South Pacific Ocean, situated about 667 km off the coast of Chile, and is composed of several volcanic islands: Robinson Crusoe, ( ) (also...

The Carnegie Ridge is a 1350-km-long and up to 300-km-wide feature on the ocean floor of the northern Nazca Plate that includes the Galápagos archipelago at its western end. It is being subducted under South American with the rest of the Nazca Plate. For the nature documentary series, see Galápagos (TV series). ...

The absolute motion of the Nazca Plate has been calibrated at 3.7 cm/yr east motion (88°), some of the fastest absolute motion of any tectonic plate. The subducting Nazca Plate, which exhibits unusual flat-slab subduction, is tearing as well as deforming as it is subducted (Barzangi and Isacks) has formed, and continues to form the volcanic Andes Mountain Range. Deformation of the Nazca Plate even affects the geography of Bolivia, far to the east (Tinker et al.). Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ... This article is about the mountain system in South America. ...

The precursor of the Nazca Plate and the Cocos Plate to its north was the Farallon Plate, which split in late Oligocene times, about 22.8 My, a date arrived at by interpreting magnetic anomalies. The Farallon Plate is an ancient tectonic plate which began subducting as Pangaea broke apart during the Jurassic period. ... The Oligocene epoch is a geologic period of time that extends from about 34 million to 23 million years before the present. ... The cause of Earths magnetic field (the surface magnetic field) is not known for certain, but is possibly explained by dynamo theory. ...

References

• Extreme Science site: "A Lesson in Plate tetonics" The basics explained.
• Galapagos rise junction (map)
• Juan Fernandez and Easter microplate (map)
• Muawia Barazangi and Bryan L. Isacks, "Spatial distribution of earthquakes and subduction of the Nazca plate beneath South America" in Geology Vol. 4, No. 11, pp. 686–692. Abstract
• Mark Andrew Tinker, Terry C. Wallace, Susan L. Beck, Stephen Myers, and Andrew Papanikolas, "Geometry and state of stress of the Nazca plate beneath Bolivia and its implication for the evolution of the Bolivian orocline" in Geology 24(5), pp. 387–390 Abstract
• Cahill, T. and B. Isacks (1992). "Seismicity and shape of the subducted Nazca plate." Journal Geophysical Research 97 (12)
• James, D. (1978). "Subduction of the Nazca plate beneath Central Peru." Geology 6 (3) pp 174 – 178
• Martin Meschede and Udo Barckhausen, "Plate tectonic evolution of the Cocos-Nazca spreading center" (pdf file)