ABOARD THE INTERNATIONAL SPACE STATION -- 11 June 2013 -- Nevados de Chillan in Chile is featured in this image photographed by an astronaut on the International Space Station

ABOARD THE INTERNATIONAL SPACE STATION -- 11 June 2013 -- Nevados de Chillan in Chile is featured in this image photographed by an astronaut on the International Space Station. This photograph highlights a large volcanic area located near the Chile-Argentina border. Like other historically active volcanoes in the central Andes ranges, the Nevados de Chillan were created by upwelling magma generated by eastward subduction of the dense oceanic crust of the Pacific basin beneath the less dense continental crust of South America. Rising magmas associated with this type of tectonic environment frequently erupt explosively, forming widespread ash and ignimbrite layers. They can also produce less explosive eruptions that form voluminous lava flows -- layering together with explosively erupted deposits to build the classic cone-shaped edifice of a stratovolcano over geologic time -- Picture by Lightroom Photos/NASA