Ridge

A ridge or mountain ridge is a geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance. Ridges are usually termed hills or mountains as well, depending on size. There are several main types of ridges:-

Villarrica

Villarrica may refer to:

Places

See also

Chile

Coordinates: 30°S 71°W / 30°S 71°W / -30; -71

Chile (/ˈtʃɪli/;Spanish: [ˈtʃile]), officially the Republic of Chile (Spanish:  República de Chile ), is a South American country occupying a long, narrow strip of land between the Andes to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far south. Chilean territory includes the Pacific islands of Juan Fernández, Salas y Gómez, Desventuradas, and Easter Island in Oceania. Chile also claims about 1,250,000 square kilometres (480,000 sq mi) of Antarctica, although all claims are suspended under the Antarctic Treaty.

The arid Atacama Desert in northern Chile contains great mineral wealth, principally copper. The relatively small central area dominates in terms of population and agricultural resources, and is the cultural and political center from which Chile expanded in the late 19th century when it incorporated its northern and southern regions. Southern Chile is rich in forests and grazing lands, and features a string of volcanoes and lakes. The southern coast is a labyrinth of fjords, inlets, canals, twisting peninsulas, and islands.

Villarrica (volcano)

Villarrica (/ˌviːəˈriːkə/ VEE-ə-REE-kə) (Spanish: Volcán Villarrica, Mapudungun: Ruka Pillañ) is one of Chile's most active volcanoes, rising above the lake and town of the same name, 750 km (470 mi) south of Santiago. It is also known as Rucapillán, a Mapuche word meaning "Pillan's house". It is the westernmost of three large stratovolcanoes that trend perpendicular to the Andean chain along the Gastre Fault. Villarrica, along with Quetrupillán and the Chilean portion of Lanín, are protected within Villarrica National Park. Guided ascents are popular during summer months.

Villarrica, with its lava of basaltic-andesitic composition, is one of a small number worldwide known to have an active (but in this case intermittent) lava lake within its crater. The volcano usually generates strombolian eruptions with ejection of incandescent pyroclasts and lava flows. Rainfall plus melted snow and glacier ice can cause massive lahars (mud and debris flows), such as during the eruptions of 1964 and 1971.

Volcano

A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.

Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle. Therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging. For example, a mid-oceanic ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates coming together. Volcanoes can also form where there is stretching and thinning of the crust's interior plates, e.g., in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "plate hypothesis" volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth. Volcanoes are usually not created where two tectonic plates slide past one another.