HR: 17:30h
AN: V24B-07    [Abstracts]
TI: Microseismicity in High Temperature Experiments: A New Tool for Studying the Seismicity Preceding Volcanic Eruptions.
AU: * Burlini, L
EM: burlini@erdw.ethz.ch
AF: Rock deformation Lab, Geological Institute, ETH, Sonnegstrasse, 5, Zurich, 8092 Switzerland
AU: Vinciguerra, S
EM: Vinciguerra@ingv.it
AF: Dipartimento di Sismologia e Tettonofisica, INGV, Via di Vigna Murata 605, Roma, 0014 Italy
AU: Meredith, P G
EM: p.meredith@ucl.ac.uk
AF: Department of Earth Sciences, UCL, Gower Street, London, WC1 6BT United Kingdom
AU: Di Toro, G
EM: giulio.ditoro@unipd.it
AF: Dipartimento di Geologia, Paleontologia e Geofisica, Via Giotto 1, Padova, 35137 Italy
AU: De Natale, G
EM: pino@ov.ingv.it
AF: Osservatorio Vesuviano-INGV, Via Diocleziano 328, Napoli, 80124 Italy
AB: A variety of seismic signals representing different physical mechanisms precede volcanic eruptions. The most meaningful signals are high and low frequency earthquakes and volcanic tremor, which have tentatively been related to fracturing and magma transport in the volcanic edifice. We provide experimental support to this association by reproducing fluid generation and migration while recording seismic signals. Both dehydration reaction and melting demonstrated to generate microseismicity (acoustic emissions) on a sample scale, which might be scaled on similar phenomena on natural scales. Opening of microfractures emits high frequency acoustic events, while the switch to low frequency and harmonic tremor accompanies the flow of melt in fractures. On the other hand water produced during dehydration reactions generates a cascade of high frequency events. Natural seismicity associated with volcanic events is characterized by spectrograms very similar to those produced in laboratory. Because length and frequency scales proportionally, we suggest the existence of a direct relationship between seismic waveforms + spectrograms and physical phenomena. Discerning between these types of seismic signals in nature can significantly refine volcanic hazard evaluation.
DE: 5102 Acoustic properties
DE: 5104 Fracture and flow
DE: 5194 Instruments and techniques
DE: 7280 Volcano seismology (8419)
DE: 8445 Experimental volcanism
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005