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3D-ambient noise surface wave tomography of Fogo volcano, Cape Verde
Carvalho, J.; Silveira, Graça; Dumont, Stéphanie; Ramalho, Ricardo Dos SantosFogo volcano belongs to the Cape Verde Archipelago, and it is one of the most active volcanoes in the Atlantic Ocean, which most recent eruption occurred from November 2014 to February 2015. We analyzed ambient seismic noise recordings of three different networks deployed in the island, totalizing 14 seismic stations, to derive a crustal 3D shear-wave crustal velocity model of the volcano. Through the phase cro...
Diverse bioerosion structures in lower Pliocene deposits from a volcanic oceani...
Dávid, Árpád; Uchman, Alfred; Ramalho, Ricardo Dos Santos; Madeira, José; Melo, Carlos; Madeira, Patrícia; Rebelo, Ana Cristina; Berning, BjörnPliocene body fossils from Santa Maria Island, Azores, have been studied for decades, but only more recently have ichnofossils received their due attention. Calcareous Pliocene deposits from the Baía de Nossa Senhora section contain numerous, diverse, well-preserved natural casts of invertebrate borings. The study of this type of fossils adds to knowledge on the dispersal of benthic faunas across oceans to volc...
Evidence for late Pleistocene volcanism at Santa Maria Island, Azores?
Ramalho, Ricardo Dos Santos; Quartau, R.; Höskuldsson, Ármann; Madeira, José; da Cruz, João Ventura; Rodrigues, AuroraSanta Maria Island constitutes the oldest volcanic island within the Azores Archipelago, with no onshore record of eruptions younger than ≈2.8 Ma. A recent high-resolution multibeam bathymetric survey, however, revealed the presence of a seemingly young submerged wide volcanic edifice at approximately −70/−80 m, on the northeastern sector of the island shelf. The outer flanks of this volcanic edifice are partia...
A geological record of multiple Pleistocene tsunami inundations in an oceanic i...
Madeira, José; Ramalho, Ricardo Dos Santos; Hoffmann, Dirk L.; Mata, João; Moreira, Mário Augusto de AndradeIn the Central Atlantic archipelagos – the Canaries, Cape Verde, Madeira and the Azores – tsunami hazard is often regarded as low, when compared with other extreme wave events such as hurricanes and storms. The geological record of many of these islands, however, suggests that tsunami hazard may be underestimated, notwithstanding being lower than in areas adjacent to subduction zones, such as the margins of the...