Solid Earth Seminar “Seismic imaging of Portugal’s Crust: 3D structure and seismicity distribution”
November 11, 2019 @ 1:00 pm - 2:00 pm
Solid Earth Seminar “Seismic imaging of Portugal’s Crust: 3D structure and seismicity distribution” by Nuno Afonso Dias
Abstract: The crustal structure in Western Iberia, is the result of a complex geodynamic history, the major episodes being the late Palaeozoic Variscan amalgamation, and the subsequent Mesozoic extension phase. The current seismicity being conditioned by the role of inherited structures. The recent surge in seismic stations operating in Portugal, allowed a significant increase of the capability for imaging the crust’s seismic 3D structure. The new 3D models provide also a finer relocation of the seismicity recorded onshore allowing to clarify the role of some tectonic structures. Besides the expected model signatures associated with the zonation of the Ibero-Armorican arc and the transitions CIZ-OMZ and OMZ-SPZ, or the anomalies associated with the Mesocenozoic Basins, is also evident that some of these zones are less homogenous than their geology suggests. The seismicity pattern is also strongly correlated with the several anomalies present in the 3D crustal Vp and Vp/Vs models.