Seismological constraints for the dyke emplacement of the July-August 2001 lateral eruption at Mt. Etna volcano, Italy

Domenico Patanè, Eugenio Privitera, Stefano Gresta, Aybige Akinci, Salvatore Arpalone, Graziella Barberi, Lauro Chiaraluce, Ornella Cocina, Salvatore D'amico, Pasquale De Gori, Giuseppe Di Grazia, Susanna Falsaperla, Ferruccio Ferrari, Salvatore Gambino, Elisabetta Giampiccolo, Horst Langer, Vincenza Maiolino, Milena Moretti, Antonino Mostaccio, Carla Musumeci, Davide Piccinini, Danilo Reitano, Luciano Scarfì, Salvatore Spampinato, Andrea Ursino, Luciano Zuccarello

Abstract


In this paper we report seismological evidence regarding the emplacement of the dike that fed the July 18 - August 9, 2001 lateral eruption at Mt. Etna volcano. The shallow intrusion and the opening of the eruptive fracture system, which mostly occurred during July 12, and July 18, were accompanied by one of the most intense seismic swarms of the last 20 years. A total of 2694 earthquakes (1 £ Md £ 3.9) were recorded from the beginning of the swarm (July 12) to the end of the eruption (August 9). Seismicity shows the upward migration of the dike from the basement to the relatively thin volcanic pile. A clear hypocentral migration was observed, well constraining the upwards propagation of a near-vertical dike, oriented roughly N-S, and located a few kilometers south of the summit region. Earthquake distribution and orientation of the P-axes from focal mechanisms indicate that the swarm was caused by the local stress source related to the dike intrusion.

Full Text:

PDF

References


DOI: https://doi.org/10.4401/ag-6302

Published by INGV, Istituto Nazionale di Geofisica e Vulcanologia - ISSN: 2037-416X