HR: 1330h
AN: V42B-0350    [PDF]
TI: Present Stage Of Activity At Colima Volcano, M‚xico
AU: * Domˇnguez, T
EM: tonatiuh@cgic.ucol.mx
AU: Ramˇrez, J J
EM: ramirez@cgic.ucol.mx
AU: Breton, M
EM: mauri@cgic.ucol.mx
AB: Colima volcano (19.51 N, 103.62 W, 3,950 m) is one of the most active volcanoes in M‚xico. It is located at the oriental end of the Mexican volcanic belt and with Nevado de Colima it forms a volcanic complex. The Colima seismic network (RESCO), has been monitoring the seismic activity since 1989 so we have records from the last three eruptions (1991, 1998-1999 and 2001-2003). During the 1998 eruption we also could measure deformation and SO2 . At the present time we are also monitoring activity with a tiltmeter network and two cameras which are continuously recording the outside activity. We also take periodically simples from springs and measures of distances. We are planning to include the measurement of three more geophysical paramenters: gravimetry, magnetometry and radon gas. The 2001-2003 eruption lasted for 15 months and it is considered the largest eruption of the last fifty years. Each eruption recorded from Colima volcano is different from the previous. The 2001-2003 eruption for example, was characterized by a very low seismic activity previous to the eruption. We also observed tremors of large amplitudes never seen before during an effusive stage. For the last seven months it has been in an explosive stage with three major explosions which have alarmed to the comunities around the volcan. The explosion of August 29th, was heard at Colima city, 32 kilometers away from the volcano. Geophysical parameters indicate that the explosive activity is due to de degassing of the residual magma trapped in the conduit and not to a new magma coming from depth.
DE: 8400 VOLCANOLOGY
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting