Tectonic Plates and Chile

 Triple junction

While most places have trenches where two large tectonic plates meet, Chile is one of the few places where three major plates meet. In other words, it is a triple junction.

The Nazca Plate, borders the South American Plate for most part of the continent. But towards the tip of the continent and bordering Chile is the Antarctic Plate.

The Nazca Plate is subducting beneath the South American Plate at a rate of 80 mm a year; the Antarctic Plate is subducting beneath the South American Plate at a rate of 20 mm per year.

What makes Chile suffer from very powerful quakes is the fact that the angle of subduction (diving) by the Nazca Plate below the South American Plate is very shallow — 5 to 15 degrees.

The place where one plate subducts beneath another is called a trench. The place where new ocean crust is formed is called a ridge. It can be seen as the recycling of the ocean crust — new ocean crust is formed at the mid-oceanic ridges and is consumed (destroyed) at the subduction zones (trenches).

Chile: where three tectonic plate boundaries meet | Science Chronicle (journosdiary.com)

https://spotlight.unavco.org/station-pages/conz/eo/scienceImage1.png

Introduction to Chile

 Chile,^[a] officially the Republic of Chile,^[b] is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica; occupying a long and narrow strip of land between the Andes to the east and the Pacific Ocean to the west. Chile covers an area of 756,096 square kilometers (291,930 sq mi), with a population of 17.5 million as of 2017.^[4] It shares land borders with Peru to the north, Bolivia to the north-east, Argentina to the east, and the Drake Passage in the far south. Chile also controls the Pacific islands of Juan Fernández, Isla Salas y Gómez, Desventuradas, and Easter Island in Oceania. It also claims about 1,250,000 square kilometers (480,000 sq mi) of Antarctica under the Chilean Antarctic Territory.^{[nb 2]} The country's capital and largest city is Santiago, and its national language is Spanish.

Chile - Wikipedia

Chile Map and Satellite Image (geology.com)