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Instituto de Investigação
em Vulcanologia e Avaliação de Riscos
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Referência Bibliográfica

​MADEIRA, J., BRUM DA SILVEIRA, A., HIPÓLITO, A., CARMO, R. (2015) – Active tectonics in the Central and Eastern Azores islands along the Eurasia-Nubia boundary: a review. In: Gaspar, J.L., Guest, J.E., Duncan, A.M., Barriga, F.J.A.S., Chester, D.K. (eds.) Volcanic Geology of São Miguel Island (Azores Archipelago), Geological Society of London Memoir, 44: 15-32, doi: 10.1144/M44.3.​​


​The geodynamic setting of the Azores archipelago, straddling the triple junction between the North America, Eurasia and Nubia plates, is reflected in frequent volcanic and tectonic activity. A review of neotectonics is presented for the islands forming the central and eastern groups of the Azores (Faial, Pico, Sa˜o Jorge, Graciosa, Terceira, Sa˜o Miguel and Santa Maria). The geometry and kinematics of active faults displacing stratigraphic and geomorphological markers of Pleistocene and Holocene age are presented. Slip-rates were determined using the available ages for the displaced markers. Maximum expected moment magnitudes were estimated using empirical correlations between magnitude and fault length, fault area and maximum observed surface displacement during surfacerupturing palaeoearthquakes. Neotectonic parameters show that the faults are in most cases very to moderately active, with slip-rates usually ranging from a few tenths of millimetres to a few millimetres per year, while maximum expected magnitudes vary from Mw 6 to 7. These magnitudes are in agreement with the instrumental and historical seismic record in the region. Neotectonic data define a dextral transtensive stress regime acting on the region and contribute to characterizing the complexity of the geodynamic processes that dominate the western-most segment of the Eurasia–Nubia plate boundary.