On 29 April 1978, eruptive activity begins at a nameless collapse pit formed during the second phase of the 1971 eruption on the southeastern base of the main summit cone, which is soon to be named "Southeast Crater". Eruptive fissures are rapidly extending southeastwards from the crater, into the Valle del Bove. The left photo shows a small cone building around one of the higher vents on the day after the beginning of the eruption. In the background are the bulky main summit cone and, at right, the cone of the NE Crater. Right photo shows a row of spatter cones building along one of the eruptive fissures on 30 April 1978. This eruption, the first of three flank eruptions in 1978, will last until early June

The third of the 1978 eruptions begins with explosive activity at the SE Crater on 18 November 1978, followed by the opening of eruptive fractures which extend from the crater to the Valle del Bove. These photos, taken during a later stage of the eruption in late November, show vigorous ash emission from the SE Crater and lava emission from a fracture on its southeastern side (the area of white gas emission). Both photos were taken from the Torre del Filosofo mountain hut, which stands about 1 km S of the crater. Compare these images to photos taken from approximately the same viewpoint in 1999-2000.