Volcano researcher at the summit crater of Pacaya volcano, a complex basaltic volcano just outside Guatemala City in Guatemala. It is one of the country's most active volcanoes. During the last several decades it has exhibited frequent Strombolian eruptions and occasional lava flows with occasional powerful eruptions. This view shows a volcanoligist monitoring steam and ash erupting from hornitos in MacKenney crater, which was exposed after an eruption destroyed the surrounding cone, the remains of which are seen here.