It is well established that Azores geodynamics is dominated by the interplay between the two main large-scale processes: tectonics of the triple junction and hot spot activity. However, the crustal structure at a segment scale, the local scale features and their interactions, that condition the volcanic and seismic hazard are not understood, due to lack of observation and monitoring in the large submarine area that surrounds the Azores Platform. To study these processes we must absolutely promote a significant effort on the observation and analysis of the most significant geophysical, geological and geochemical structures and processes in the Azores platform, and we must study the coupling between the regional scale, dominated by the interaction between plate tectonics and Azores Hot Spot, and the local scale, dominated by the magmatic and tectonic processes that shape islands and basins. This is the aim of the STAMINA.
STAMINA will focus the attention on the tectonically more active sector around the Terceira Axis, between Graciosa and S Miguel. This area will be the target of a series of studies. In Terceira island, we will develop volcano stratigraphy of the main systems, neotectonic mapping of active and paleo faults and measurement of present day deformation by a dense GPS array. In the surrounding plateau we will make a detailed swath bathymetry survey, with sample acquisition by dredging and coring.
The coupling between the regional and the local scale will be mainly achieved by experimental seismology. In the framework of STAMINA we will acquire the first MCS profiles in the Azores area. With MCS profiles we expect to resolve the detailed structure of the main seismogenic and volcanic source areas, both at crustal and sub crustal levels. A new OBS survey and a deep MT sounding will also complement active seismics.
The correlation between field observations, over the islands, and indirect interpretation of active faults, over the submarine plateau, will be based on the use of remote sensing data that cover continuously the whole area: the swath imagery at the plateau and the radar imagery over the islands. Tectonic models will be tested with the use of experimental tectonic techniques, involving in particular, the simulation of transtensional regimes in the presence of topography.
All these sources of information will be finally integrated. The aim of STAMINA is to design a comprehensive model for the tectono-magmatic interplay in the Azores, valid at the “segment scale", and able to incorporate the main conclusions of a series of detailed and complementary approaches. Besides its own interest as a typical signature of a peculiar geodynamic environment, this understanding is critical if we want to be able to address the geo-hazards that strongly impend on the populations.