Nazca plate

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Tectonic plates with continents in the background, in the middle (marked light blue) the Nazca plate

The Nazca plate is one of the smaller lithospheric plates that make up the earth's crust and the uppermost part of the earth's mantle . The tectonic plates play an essential role in the large-scale geological processes on earth . The plate is named after the Peruvian port city of Nazca .

The Nazca Plate is located off the west coast of South America and is one of the oceanic plates that - with the exception of a few small islands, such as the Juan Fernández Islands - are mostly covered by the sea. The plate moves to the east and there collides with the South American plate , a continental plate. When these two plates collided, the Nazca plate was pushed under the South American continent and dipped there into the lower mantle; a subduction zone formed . Typical of these zones are the deep earthquakes , the hypocenters of which can lie at depths of 320 to 720 km. At the boundary between the two plates were formed deep trenches such as the Atacama trench (up to 8065 m depth) to the south and the Peru trench (up to 6369 m deep) in the northern part of the South American west coast. At the same time, the South American continent was raised. As a result of plate shift it came to the mountain formation : All along the west coast of South America folded a large mountain on which Andean m with a height of up to 6,962th

The Andes are part of the Pacific Ring of Fire , an area of ​​strongest seismic and volcanic activity. The highest volcanoes on earth are here: The 6,882 m high Monte Pissis ( Argentina ) and the 6,887 m high Ojos del Salado ( Chile ). Post-volcanic phenomena such as solfataras , geysers and fumaroles are common.

In the north the Nazca plate borders on the Cocos plate , in the west it is bordered by the Pacific plate and in the south by the Antarctic plate . In the east it meets the South American continent and is subducted there.

The Nazca Plate was created by the fragmentation of the Farallon Plate at the beginning of the Miocene about 23 million years ago. The existence of at least two microplates was postulated for the area between the Cocos Plate, Caribbean Plate and South American Plate shown in the simplified maps of the lithospheric plates as the northern extension of the Nazca Plate: the Coiba plate in the north and the Malpelo plate in the south.

See also

Individual evidence

  1. Tuo Zhang, Richard G. Gordon, Jay K. Mishra, Chengzu Wang: The Malpelo Plate Hypothesis and implications for nonclosure of the Cocos-Nazca-Pacific plate motion circuit. Geophysical Research Letters. Vol. 44, No. 16, 2017, pp. 8213–8218, doi: 10.1002 / 2017GL073704 (Open Access).