Study of the seismic-tidal correlations for preeruptive, eruptive and post-eruptive stages of the submarine volcano Tagoro, El Hierro Island

Abstract

During the seism-eruptive process that took place at the island of El Hierro (Canary Islands) between 01/01/2011-31/07/2012, more than 15,000 earthquakes distributed during the different stages (pre-eruptive, eruptive and post-eruptive), were registered. This eruptive process gave the opportunity to analyze the possible existence of any relation between earthquakes and tide for each of the stages of the process. In order to verify that, several earthquakes swarms were selected from each stage. Subsequently, each swarm was subjected to different spectral analysis techniques. The results obtained in this work, demonstrated the existence of a strong influence of the tide with earthquakes, especially in the pre-eruptive stage and the reactivation swarm of the posteruptive stage. It is also noteworthy, that the influence of the semi-diurnal tide respect to the probability of occurrence of earthquakes is more significant than the diurnal tide. Moreover, this study also demonstrated the existence of higher occurrence of earthquakes during events of low tide with respect to high tide.