Report on Colima (Mexico) — 20 October-26 October 2004
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 October-26 October 2004
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2004. Report on Colima (Mexico). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 20 October-26 October 2004. Smithsonian Institution and US Geological Survey.
19.514°N, 103.62°W; summit elev. 3850 m
All times are local (unless otherwise noted)
During 22-26 October, block-lava flows continued to travel down Colima's N, NW, W, and S flanks as they have since 30 September. On the 26th, the block-lava flows on the N flank reached a length of ~1,800 m and a width of 200 m, and on the WNW flank the block-lava reached a length of ~600 m and a width of 200 m. On the 22nd, the volcano's gas output included 840 metric tons of sulfur dioxide. During the report period, block-and-ash flows spilling from the fronts of the advancing block-lava flows reached ~ 2 km from the summit.
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.