HR: 0800h
AN: V21C-0610    [Abstracts]
TI: Time-Scale Wavelet Analysis Related to the 1998-2005 Eruptions of the Colima Volcano, Mexico
AU: * Vargas B., D M
EM: marsden77@gmail.com
AF: Centro de Sismologia y Volcanologia de Occidente. Universidad de Guadalajara., Av Universidad 203. Del. Ixtapa, Puerto Vallarta, Jal 48280 Mexico
AU: Nava, F A
EM: fnava@cicese.mx
AF: Departamento de Sismologia. Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE)., Km. 107 Carretera Tijuana-Ensenada, Ensenada, BC 22860 Mexico
AU: Reyes-Davila, G A
EM: gard@cgic.ucol.mx
AF: Observatorio Vulcanologico. Universidad de Colima., Av. 25 de Julio #965. Col. Villa San Sebastian, Colima, Col 28045 Mexico
AB: The seismic activity from one of the most active (documented) periods of the Colima volcano, from October 1998 to July 1999, was analyzed, using the wavelet transform, to study the evolution in time of energy content at different scales of seismic signals preceding eruptive episodes. During this analyzed period four significant volcanic events took place. An effusive stage began on November 20, 1998 and ceased about 80 days later changing to a period of intermittent explosions and continuous degassing. Significant large explosions occurred on February 10, May 10 and July 17, 1999 with eruptive columns as high as 10 km and incandescent blocks reaching distances about 5 km from the crater. Time-scale analysis performed for this period showed significant seismic energy concentrations at certain scales preceding significant eruptions, relative to non-eruptive stages. Based on a quantification of the observed wavelet patterns, an empiric method for determining the impending occurrence of significant effusive or explosive eruptions was developed. Since 1999, small to moderate explosions have been presented at Colima volcano. During March to July, 2005 a sequence of relatively large explosions occurred, some having the largest amplitudes on their seismic signals since the seismic network was deployed. Further time-scale analysis of the large explosions occurred after those of 1999 will be presented along with their implications for eruption forecasting.
DE: 7280 Volcano seismology (8419)
DE: 8419 Volcano monitoring (7280)
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005