Report on Colima (Mexico) — 14 October-20 October 2015
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 October-20 October 2015
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2015. Report on Colima (Mexico). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 14 October-20 October 2015. Smithsonian Institution and US Geological Survey.
19.514°N, 103.62°W; summit elev. 3850 m
All times are local (unless otherwise noted)
The Unidad Estatal de Protección Civil de Colima reported that on 6 October scientists conducted an overflight of Colima and noted that the summit crater was 200 m wide and 50 m deep. Explosions had excavated parts of the crater, exposing the inner wall stratigraphy in the W and N parts of the crater. Fumarolic plumes rose from vents outside of the crater and from the SE interior. Weaker fumarolic activity was present in the NE and W sectors. An explosion on 5 October had produced a small pyroclastic flow that had traveled 2.1 km down the flanks. The report reminded the public to stay at least 5 km away from the crater, and 12 km away in the Montegrande drainage. Based on satellite images, wind data, webcam views, and notices from the Mexico City MWO, the Washington VAAC reported that during 13-16 and 18-19 October ash plumes from Colima rose to altitudes of 5.5-6.7 km (15,000-22,000 ft) a.s.l. and drifted SW and NW.
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.