Estimating the effective elastic thickness of the lithosphere of the Iberian peninsula based on multitaper spectral analysis

Abstract

Effective elastic thickness of the lithosphere of the Iberian peninsula was estimated from a coherence analysis of topography and gravity spectra, for which a multitaper technique was used. Coherence estimates provide an average Te value of 17 ± 4 km. To verify the Te derived from the spectral analysis, we compare it to independent Te estimates from strength envelopes constructed for some tectonic units located at the interior of the Iberian peninsula.We obtain Te values ranging from 10 to 25 km. These values are consistent with coherence results. Tectonic evolution of the area involved an Early Mesozoic rifting (Late Permian—Early Cretaceous) and a subsequent period of compression. Present morphotectonic units result from Alpine deformation events (mainly Neogene). No widespread volcanism activity or/and high heat flow values have been reported to have occurred during intraplate domain deformation. The Iberian lithosphere response to loading primarily reflects its pre-existing inherited mechanical structure, which has remained thermally relatively unperturbed.