Report on Colima (Mexico) — July 2003
Bulletin of the Global Volcanism Network, vol. 28, no. 7 (July 2003)
Managing Editor: Edward Venzke.
Colima (Mexico) Small explosions produced, including two on 17 July; absence of lava flows
Please cite this report as:
Global Volcanism Program, 2003. Report on Colima (Mexico) (Venzke, E., ed.). Bulletin of the Global Volcanism Network, 28:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200307-341040.
19.514°N, 103.62°W; summit elev. 3850 m
All times are local (unless otherwise noted)
Explosive activity at Colima continued in May and July 2003. A small explosive eruption reported at 1024 on 2 May 2003 produced an ash cloud visible on satellite imagery and monitoring cameras, but rising to no more than 500 m above the crater. The Mexico City Meteorological Watch Office stated that the plume moved SW of the summit at 5-10 knots (9-18 km/hour). The Washington VAAC described the plume as very small.
Nick Varley pointed out on 18 May that the GVP / USGS Weekly Volcanic Activity Report for 7-13 May 2003 incorrectly reported lava flows at Colima. He noted that "No lava has been produced since the beginning of March . The current activity comprises small explosions, on average some 25 per day, some containing ash. The dispersal of the ash is limited to approximately 7 km from the summit."
More significant explosions were reported on 17 July 2003. The first, at 0527, threw incandescent material 500 m high and an ash column to ~3 km height that blew SW . Small forest fires caused by the incandescent material 2.5-4 km SW of the crater suggested that the explosion was also directed to this sector. An explosion at 1400 on 17 July, produced an ash-laden cloud 1,000 m high, again dispersing SW. The seismic energy released by the 0527 explosion was reported to be less than half that released in the 1999 explosions.
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 high point of the complex) on the north and the historically active Volcán de Colima at the south. A group of late-Pleistocene cinder cones is located on the floor of the Colima graben west and east of the 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, producing thick debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions have destroyed the summit (most recently in 1913) and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.
Information Contacts: Observatorio Vulcanologico de la Universidad de Colima, Colima, Col., 28045, México (URL: https://portal.ucol.mx/cueiv/); Nick Varley, Facultad de Ciencias, Universidad de Colima Av. 25 de Julio 965, Col. San Sebastian Apdo. postal 25, Colima, CP 28045, México.