Abstract AGU FALL 2001

April D. McGreger

Jonathan M. Lees

Quantitative Discrimination of Vent Explosions at Stromboli Volcano, Italy

 As part of the multidisciplinary STROBE Experiment (STROmbolian BEhaviour) of May 2001, we deployed a broad band seismo-acoustic array around the summit craters of Stromboli Volcano, Italy.  Three broadband instruments and five short period stations were each equipped with infrasonic microphones to measure the acoustic wave field from the nine events that were active over a period of 10 days.  Explosion activity during the deployment was especially intense with numerous vents erupting with repose times of a few minutes.  Several of the vents have consistent seismic and acoustic source signatures which allows us to distinguish between explosions based on cross correlation cluster analysis and frequency response of the multivariate time series.  For example, the northeast crater consistently exhibited long period waves, greater than 10 s in wavelength, although the southwest crater does not contain this response.  In spite of the broad band deployments we did not record any local tectonic earthquake activity.  The variety of source activity suggests a complicated near surface conduit system where the dynamics of energy transfer to the atmosphere is controlled by vent structure and geometry.  The activity at Stromboli differs considerably from observations at single vent systems like Karymsky, Russia or Sangay Volcano, Ecuador.