Iniciar sessão

Navegar para Cima
Instituto de Investigação
em Vulcanologia e Avaliação de Riscos
Última hora:

Painéis ► em encontros internacionais


Referência Bibliográfica

SENOS, M.L., GASPAR, J.L., CRUZ, J., ALVES, P. (2000) - The Seismicity of Azores Islands (1990-1999). “XXVII General Assembly of the European Seismological Commission”. Lisboa, 10 - 15 de Setembro (Poster).


The Azores islands have a high seismicity due to its geographical location, near the junction of the Eurasian, American and African plates. Two of the three branches, are related with the Mid-Atlantic Ridge. The nature of the connection between Eurasian and African plates is still controversial, especially in the Azores Plateau. That segment is known as Terceira Ridge. The seismicity of that branch is extremely high in frequency. Catastrophic events are common since the discovery of the islands, in the XV century. Catastrophic events are expected also to occur in the future. In order to understand better the tectonic regime of Terceira ridge it is important the description and characterisation of the seismic activity. The purpose of this work is the detailed description of the seismic activity between 1990 and 1999.
The main events, during this decade, were: the seismic swarm in 1992/1993, 30 kilometres to the West of Faial Is.; the seismic swarm located to the NW of a volcanic structure known as D. João de Castro Bank, between Terceira and S. Miguel islands during 1997; the 1998 July 9 catastrophic event (nine casualties, hundreds of injuries and a great amount of damages) and the subsequent seismic swarm; the seismic swarm in Sete Cidades volcanic massif located in S. Miguel Is.; the seismo-volcanic swarm 10 km West of Terceira Island, in Serreta region, related with the ongoing submarine eruption. Many other small seismic swarms were also recorded.
So, the activity, during this decade, seems to be representative of the seismicity of Azores region with periods of low level activity (between middle 1993 and middle 1997) and periods with higher levels.
This shows the importance of the seismic networks that allow the monitorization to understanding the nature of the tectonic processes in this unique region.