Crustal thickness maps at regional scales are typically compiled using estimations inferred from different geophysical datasets providing a variable coverage of the investigated area. Consequently, spurious effects related to changes in data resolution or artifacts in grid interpolation may affect significant zones of those maps. The TopoIberia-IberArray broad-band seismic network, covering the Iberian Peninsula and Northern Morocco with stations distributed on a regular 60 × 60 km grid provides a unique opportunity to avoid such technical problems and to obtain a crustal thickness map derived from a same method sampling evenly all the region. Data from more than 340 stations has been gathered and analyzed using the P-to-S conversion phases at the Moho discontinuity (receiver functions). The crustal thickness has been inferred applying the classical H-κ stacking technique, though in regions of complex crustal structure, we have preferred to estimate the thickness directly from the arrival time of the converted phase at some sites.The topography of the Moho discontinuity is strongly correlated with tectonic processes. The investigated area, extending from the Sahara platform to the Bay of Biscay, has a great geodynamic diversity, including, North to South, crustal imbrication in the Pyrenean and Cantabrian range, a large and relatively undisturbed Variscan Massif in the center of Iberia and areas of complex and still not completely understood geodynamics in the Alboran crust domain and the Atlas range. The crustal thickness map reflects this diversity, showing variations reaching 30. km between the thickest and thinnest zones of continental crust. The final map has an overall similarity with previous estimations of the crustal thickness using independent data, as those coming from more sparse deep seismic sounding profiles, but provides further constraints at regional scale.

This is a contribution of the Consolider-Ingenio 2010 project TOPO-IBERIA [CSD2006-00041]. Additional funding is provided by projects RIFSIS [CGL2009-09727], Siberia [CGL2006-01171], Topomed [CGL2008-03474-E/BTE, ESF-Eurocores 07-TOPOEUROPE-FP006], INDALO [CGL2008-01830], TRANSCORBE [CGL2012-31472], MISTERIOS [CGL2013-48601-C2-1-R and the Project “Imagen 3D de la estructura litosférica y del manto superior de la Península Ibérica y norte de Marruecos: hacia un nuevo modelo geodinámico” funded by the Granada University. The Portuguese temporary deployments were supported by Fundação para a Ciência e Tecnologia through projects WILAS (PTDC/CTE-GIX/097946/2008) and AQUAREL (PTDC/CTE-GIX/116819/2010). The Morocco Münster project is funded under grant DFGTH1530/5-1. The PYROPE experiment was supported by the French Research Agency ANR blanc program (project PYROPE, ANR-09-BLAN-0229).

Peer Reviewed