Introduction
From the Caribbean coast of Columbia to the frigid fjords of Patagonia, the Andean cordillera extends in an unbroken range; in places it is a single, narrow spine; in others, a crumpled web of several different ranges. Extending for about 7500 km, the cordillera forms one of the longest continuous mountain chains on Earth. Dozens of peaks along its length exceed 6000 m altitude. Many of them are potentially active volcanoes.
The Andean plate margin provides arguably the best developed example of continental margin magmatism in the world. Subduction of the oceanic Nazca plate beneath the western margin of the continental South American plate has resulted in three principal zones of active volcanism: the Northern Zone (in Ecuador and Columbia), the Central Zone (southern Peru, northern Chile, southwestern Bolivia, and northwestern Argentina), and the Southern Zone (southern Chile and southern Argentina). Because they are often densely populated, the northern and southern zones are both relatively well known. Although much remains to be learned, at least the identities and locations of the major volcanoes have been documented. By contrast, the Central Volcanic Zone of the Andes remains one of the largest but least known areas of active volcanism in the world.
The Central Volcanic Zone of the Andes is located between latitudes 14ºand 28ºS of the Andean cordillera (Figure 2). An elevated region, much of it over 4,000m in altitude, constituting the altiplano of Bolivia and puna of north Chile and Argentina, dominates much of this zone (Figure 2). This high altitude plateau is second in size only to the great Tibetan plateau of Central Asia, and like the latter, is built on thickened continental crust which attains a maximum thickness of almost 70 km (James, 1971). Volcanism is largely restricted to the margins of this remarkable physiographic province in theCordillera Occidental or Western Cordillera, with a few isolated examples in the Cordillera Oriental or Eastern Cordillera in Bolivia. So little is known about this area that the majority of the volcanoes have never been described, and in a few cases, have not even been named. 16 of them were considered to be "active" when the existing Catalog of Active Volcanoes of the World was published (1963-1966).
The intention of this website is to allow a comprehensive look at the volcanism of the Central Volcanoic Zone (CVZ) of the Andes cordilleran. Much of the central portion has been researched and compiled by S.L. de SIlva and P.W. Francis in Volcanoes of the Central Andes, published by Springer-Verlag (1991). It is intended for this site to be an electronic companion to that volume with the added enhancements, of course, of ease of access and continual updates. More projects are in the works in this poorly known region of South America, including a proposed installation of Global Positioning System receivers in a potentially hazardous volcanic region of Peru, as well as a preliminary hazard assessment project for the Arequipa, Peru, region. This project aims to set up a framework to allow a volcanic hazard warning system for the residents of that area to be realized.
The ultimate goal of this online resource is to one day have available to researchers and other individuals a wealth of knowledge concerning this region of the world, perhaps spawning further research. It is hoped that at some point every volcanic area in the Andes cordilleran will be able to be studied remotely and accurately with the help of stores of information such as this website.