the English abstract of the paper “Fifty years after the Capelinhos eruption we cannot find any tree or bushes on the volcano. IUGS geological heritage site In respect of its importance in enhancing understanding of submarine volcanoes, Capelhinos was included by the International Union of Geological Sciences (IUGS) in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022. History The Capelinhos eruption represented the first time that a submarine eruption was documented from beginning to end. Its location near an inhabited island with good communications meant it could be intensively studied. The first activities during the eruption were identified by engineer Frederico Machado, the Director of the District Public Works Department, his assistant engineer João do Nascimento and surveyor António Denis, under the authorization of the Civil Governor, Freitas Pimentel. The Director of the Observatory in Angra, Lieutenant-Colonel José Agostinho overflew the area, and Bernado Almada (at the Prince Albert of Monaco Observatory, in Horta) sent several bulletins relating the increased seismic activity of the area. Between September 16 and 27, 1957, 200 earthquakes of intensity V (Moderate) on the Mercalli scale were registered. On September 23, the ocean waters off the coast of Ponte dos Capelinhos began to boil, and the first vapours were witnessed around 6:30 a.m. one kilometre northwest of the lighthouse. A constant tremor could be sensed, at times reaching a Level IV on the Mercalli scale (MM-31). Three days later, the activity increased; black ash (to about 1400 m) and water vapour (to about 4000 m) rose west of the two ilhéus () off the coast. On September 27, beginning at about 6:45 in the morning, a submarine eruption, 300 m from Ponta dos Capelinhos (100 m from the Ilhéus dos Capelinhos) began. Whale spotters at Costado da Nau, a few meters above the Capelinhos lighthouse, saw the ocean churning to the west and alerted the lighthouse keepers. On October 5: "...the clouds of clay likely rose about one kilometre in height and solid fragments...reaching an area of 1200 metres around..." The buildings in the area began to experience the first damages: windows were broken, tiles fell from the roofs. By the next day, the first ash-fall began on land; "in a few hours a black mat covered the extreme West of island...", reaching 2.5 kilometres from the crater, necessitating the evacuation of the settlements of Norte