Report on Colima (Mexico) — 21 February-27 February 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 21 February-27 February 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Colima (Mexico). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 21 February-27 February 2001. Smithsonian Institution and US Geological Survey.
19.514°N, 103.62°W; summit elev. 3850 m
All times are local (unless otherwise noted)
The Volcanological Observatory of Colima University reported that a moderate explosion occurred at 0532 on 22 February. After reviewing video footage of the eruption, the observatory concluded that the ash cloud produced from the eruption rose ~2 km above the volcano at an average velocity of 200 meters/second (m/s). Incandescent ballistics were hurled up to 3 km away from the volcano at a rate of ~100 m/s and landed on the NE and SW flanks of the volcano, and to a lesser extent on the N flank. Large blocks, up to several meters in diameter, rolled ~400 m from the volcano's summit. The collapse of the eruptive column generated small pyroclastic flows that traveled towards the SW. Small amounts of ash fell in the towns of San Marco ~14 km SE of the volcano and Tonila ~13 km to the SSE. According to the observatory, the events were not sufficient to trigger an expansion of the zone of exclusion around the volcano, which remained at 6.5 km.
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.