Geology topics

Research about Nazca Plate

Source-linked reports with geographic coverage including Nazca Plate.

2 recordsLinked to original sources

USGS2012

The 9 June 94 Bolivian Deep Earthquake: An exceptional event in an extraordinary subduction zone

We investigate the physical setting of the Bolivian shock based on the history of the subducting Nazca plate, intraslab seismicity, deep seismic moment release, and seismic tomography. South America has two broad regions of reverse arc curvature. Subduction constrained to this unique geometry produces slab kinking contortions that may cause unusual slab thickening as they sink to the bottom of the transition zone and encounter resistance to penetration into the lower mantle. Such contortions are observed at intermediate depths “upstream” from the slab source regions of both the great 1970 Colombian and 1994 Bolivian events. Thickening helps explain how the Nazca slab accommodates large seismic source dimensions at depths of 625–650 km.

Geophysical Research Letters↗

USGS2010

Seismicity of the Earth 1900-2007, Nazca Plate and South America

The South American arc extends over 7,000 km, from the Chilean triple junction offshore of southern Chile to its intersection with the Panama fracture zone, offshore the southern coast of Panama in Central America. It marks the plate boundary between the subducting Nazca plate and the South America plate, where the oceanic crust and lithosphere of the Nazca plate begin their decent into the mantle beneath South America. The convergence associated with this subduction process is responsible for the uplift of the Andes Mountains, and for the active volcanic chain present along much of this deformation front. Relative to a fixed South America plate the Nazca plate moves slightly north of eastwards at a rate varying from approximately 80 mm/yr in the south to approximately 70mm/yr in the north.

Open-File Report↗