Broadband measurements of the sources of explosions at Stromboli Volcano, Italy

Chouet, Bernard; Saccorotti, Gilberto; Dawson, Phillip; Martini, Marcello; Scarpa, Roberto; De Luca, Gaetano; Milana, Giuliano; Cattaneo, Marco
Referencia bibliográfica

Geophysical Research Letters, Volume 26, Issue 13, p. 1937-1940

Fecha de publicación:
7
1999
Número de autores
8
Número de autores del IAC
0
Número de citas
85
Número de citas referidas
85
Descripción
During September-October 1997, 21 three-component broadband seismometers were deployed on Stromboli Volcano at radial distances of 0.3-2.2 km from the active crater to investigate the source mechanisms of Strombolian explosions. In the 2-50 s band, the very-long period (VLP) signals associated with explosions are consistent with two stationary sources repeatedly activated in time. VLP particle motions are essentially linear and analyses of semblance and particle motions are consistent with a source centroid offset 300 m beneath and 300 m northwest of the active vents. Similar VLP waveforms are observed at all 21 stations, indicating that the seismograms are source-dominated. The VLP ground displacement response to each explosion may be qualitatively interpreted as: (1) pressurization of the conduit associated with the ascent of a slug of gas; (2) depressurization of the conduit in response to mass withdrawal during the eruption; and (3) repressurization of the conduit associated with the replenishment of the source with fluid.