Due to its peculiar geodynamic setting, located near the Mid Atlantic Ridge where the North American, Eurasian and African lithospheric plates interact, the Azores archipelago is the scenery of important seismo-volcanic activity. During more than five hundred years of history, the Azores islands were affected by several major earthquakes and about 30 volcanic eruptions that caused great impact in their development.
The first efforts to monitor the seismicity of the Azores date back to 1902 and until the seventies three seismic stations were in operation on the archipelago. Only with the development of the geothermal exploration program, in 1976, and in the sequence of the 1980 earthquake that stroke the islands of Terceira, S. Jorge and Graciosa, the seismic activity started to be surveyed in detail and epicentral maps of the Azores came to be produced.
In 1997, the Centro de Vulcanologia e Avaliação de Riscos Geológicos (CVARG) together with the Instituto de Meteorologia (IM) set off a co-operation programme leading to the creation the Azorean Seismic Surveillance System (SIVISA). The merging of both seismic networks represented a very important step towards the data harmonization in a single regional database.
Presently the CVARG continues to increase the efforts to improve its seismo-volcanic monitoring capabilities in order to enhance its response to the Azorean Civil Defence authorities. Within this scope CVARG is the scientific and technical advisor for geological hazards assessment and crisis management. It is organised in two major lines of action, the Volcanological Observatory and the Geological Risks Assessment Observatory. Groups of researchers in the fields of the seismology, volcanic seismology, fluids geochemistry, ground deformation and volcano-magmatic processes developed and implemented robust monitoring techniques and routines, complemented by risk analysis and vulnerabilities evaluation, all supported by a solid GIS team, in order to continue to expand and improve its response capacity. The reinforcement of its international relations with R&D institutions in the field of volcanology, with the development and participation in international research projects, is also contributing to the exchange of know-how and improvement of its expanding seismo-volcanic activity monitoring program.