The project is based on a collaborative research between Centro de Vulcanologia e Avaliação de Riscos Geológicos (CVARG) and University of Roma Tre, by means of application of paleomagnetic techniques in order to study the emplacement processes of pyroclastic flows in Sete Cidades volcano (Sao Miguel Island, Azores).
Sete Cidades volcano is located to northwest sector of the Sao Miguel island and is one of three active volcanoes of the island, which have triggered several explosive eruptions in the last 5000 years, typically with sub-plinian and phreatomagmatic characters (Queiroz et al., 2008).
The most evident morphological feature of the volcano is represented by a broadly 5 km-wide circular caldera. The caldera is considered as the result of at least three separate collapse episodes, each associated with explosive eruptions and emplacement of pyroclastic flows in the last 36 ka. The volcanic history of the caldera-forming eruptions is very poor understood. Despite their importance to volcanic hazard, the deposits associated to caldera collapses have been the focus of few chronological and correlation studies (see Queiroz, 1997; Queiroz et al., 2008). Little information has been also given to stratigraphy and physical features of these deposits.
This project is based on a multidisciplinary approach between field and paleomagnetic works aimed to reconstruct the stratigraphy, associated to caldera-forming eruptions, and acquire paleomagnetic data which will be interpreted in terms of emplacement temperatures of the pyroclastic flows.
The integrated field and magnetic data will be used for the first time to define a comprehensive model of deposition of very dangerous pyroclastic flows related to Sete Cidades volcanic eruptions. The results of this research will considerably enhance mitigation of volcanic risk associated with pyroclastic flows in a densely inhabited area such as Sao Miguel Island.