Features of the deep structure of some volcanic islands of the Canary Archipelago from the passive seismo-prospecting method

Abstract

Trabajo presentado en el 26º UGG General Assembly, celebrado en Praga (República Checa) del 22 de junio al 2 de julio.The Microseismic Sounding Method (MSM) [Gorbatikov, etc., 2008,2011,2013] belongs to group of passive methods of seismic prospecting and can be applied at the solution of geologic-geophysical and structural problems to various classes of geological objects, and considering various geographical and climatic conditions. The model of formation of a microseismic field in MSM doesn't proceed from the obligatory horizontal lamination of the medium. In this regard, it is considered that the main contribution to a microseismic field is provided by fundamental Rayleigh modes, and the existence of the highest modes is minimum. Informative parameter (a useful signal) in MSM is extent of distortion of initial amplitude field of microseisms due to interaction with velocity inclusions. The phase information is not used. The form and depth of the heterogeneity is estimated through the distribution of the distortions of the initial field at the surface, and the frequency at which these distortions are manifested as well. The MSM method was applied to estimate the models of the deep structure of several islands of the Canary Archipelago: El Hierro, Lanzarote and Gran Canaria. The respective velocity models obtained were then compared in independent studies: 1) with distribution of micro-seismicity and inversion of the gravity field at El Hierro Island, 2) with inversions of gravity and magnetic fields, and with morphological and structural maps at Lanzarote and Gran Canaria islands. A good correlation with the results of various methods has been found.Peer Reviewe