Report on Colima (Mexico) — September 1988
Scientific Event Alert Network Bulletin, vol. 13, no. 9 (September 1988)
Managing Editor: Lindsay McClelland.
Colima (Mexico) 1987 phreatic explosion and avalanche from summit dome
Please cite this report as:
Global Volcanism Program, 1988. Report on Colima (Mexico) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 13:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198809-341040.
19.514°N, 103.62°W; summit elev. 3850 m
All times are local (unless otherwise noted)
On 2 July 1987, residents of the S side of Colima observed a mushroom cloud 500-1,000 m high emerge from the central dome, accompanied by a loud explosion. Tons of volcanic material fell on the SE side of the cone. Municipal authorities requested assistance, and a group of security personnel and two geologists from Guadalajara were sent to investigate. Their report described the activity as a "phreatic explosion from the central dome and an avalanche... of volcanic material accumulated forming the dome" (Flores and others, 1987).
The same two geologists and another from the National Univ climbed the volcano on 20 April 1988. The dome, 250-300 m in diameter, had a large depression (100 m diameter, 50 m deep [but see 15:12]) on its SE side. Only fragmented older rocks were found on the dome and in the avalanche; there was no evidence of fresh glass.
Fumarolic activity from three sites on the dome is watched by telescope from Ciudad Guzmán, 20 km NE. Weekly reports are sent to the Geography Department at the Univ of Guadalajara, 132 km N of the volcano. Geologists from the Univ visit the volcano every two months if weather permits.
Reference. Flores, J., and others, 1987, Informes de las recientes observaciones practicadas en el Volcan Colima: Revista del Instituto de Geografia y Estadistica, Universidad de Guadalajara, México, v. 3, no. 2.
Geologic Background. The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the 4320 m high point of the complex) on the north and the 3850-m-high historically active Volcán de Colima at the south. A group of cinder cones of late-Pleistocene age is located on the floor of the Colima graben west and east of the Colima complex. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the south, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.
Information Contacts: Julian A. Flores Diaz, Instituto de Geografia y Estadistica, Univ de Guadalajara.