Tremor source location based on amplitude decay

Abstract

A 3D grid search method for the location of the volcanic tremor source was applied to data recorded at Mt. Etna in 2004 [Di Grazia et al., 2006]. The aim of that application was to highlight changes in time and space of the location of the tremor source, heralding the onset of a lava emission on 7 September, 2004. The time span investigated ranged from January to November 2004. The method exploits the amplitude decay of the seismic signal recorded at permanent stations used for monitoring purposes. Consequently, it does not require any additional set up of temporary, mobile stations. We present here the results of that application, which was followed in the autumn of 2006 by the successful implementation of the method we named TREMLOC, as an automated and continuous near real time analysis for the location of volcanic tremor at the Istituto Nazionale di Geofisica e Vulcanologia (INGV) - Sezione di Catania.