Report on Colima (Mexico) — 15 May-21 May 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 15 May-21 May 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Colima (Mexico). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 15 May-21 May 2002. Smithsonian Institution and US Geological Survey.
19.514°N, 103.62°W; summit elev. 3850 m
All times are local (unless otherwise noted)
A strong increase in volcanic tremor at Colima caused the Scientific Committee on 18 May to evacuate hundreds of residents from several towns on the SW and SE flanks. Scientists also recorded changes in deformation, the chemistry of spring water near the volcano, and the composition of ejected rocks. In addition, heightened temperatures were recorded on infrared imagery. On 21 May there was an increase in the number of explosive-type earthquakes and a slight decrease in tremor earthquakes in comparison to the previous day. The 6.5-km-radius exclusion zone around Colima remained in effect, with other restrictions to access out to 11.5 km from the volcano's 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.