Report on Colima (Mexico) — 29 May-4 June 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 May-4 June 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, 29 May-4 June 2002. Smithsonian Institution and US Geological Survey.
19.514°N, 103.62°W; summit elev. 3850 m
All times are local (unless otherwise noted)
During 28-31 May, volcanic tremor, small explosions, and lava avalanches continued to occur at Colima. On 29 May infrared images revealed that 70 landslides occurred in 11 hours and there were six emissions that included incandescent material. According to the Universidad de Colima, by 3 June activity was relatively low at Colima, similar to levels observed before 10 May. By this time activity consisted mainly of slow lava emission towards the W and SW and an average of 136 landslides per day was reported. By 3 June the level of tremor had remained the same for ~48 hours and no explosive events had occurred. During the report period, incandescent lava avalanches traveled down the volcano's S, SW, and W flanks and no significant deformation was detected at the volcano. Based on information from the Mexico City MWO, the Washington VAAC reported that a pilot observed ash between 2.7 and 4 km a.s.l. near Colima's summit on 2 June at 1318. No ash was visible on satellite imagery in clear conditions. Due to the decreased level of activity, authorities considered ending the preventative evacuation of residents in towns on the volcano's SW and SE flanks, but had not done so as of 3 June.
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.