Based on multiple sources including webcam and satellite images, the Mexico City MWO, and Jalisco Civil Protection agency, the Washington VAAC reported that ash plumes from Colima rose to altitudes of 4.7-6.7 km (15,400-22,000 ft) a.s.l. and drifted N, NE, and SW during 18-20, 22, and 24 October.

On 21 October the Unidad Estatal de Protección Civil de Colima reported that lava continued to flow down the S flank. The lava flow was 2.3 km long, 320 m wide, and had an estimated volume of 21 million m3. Low-to-moderate explosions continued. The exclusion zone was maintained at 12 km in the Montegrande canyon (SSE) and 8 km on the other flanks.

Geological Summary. The Colima complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the high point of the complex) on the north and the historically active Volcán de Colima at the south. A group of late-Pleistocene cinder cones is located on the floor of the Colima graben west and east of the complex. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide scarp, 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, producing thick debris-avalanche deposits on three sides of the complex. Frequent recorded eruptions date back to the 16th century. Occasional major explosive eruptions have destroyed the summit (most recently in 1913) and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.

Sources: Washington Volcanic Ash Advisory Center (VAAC), Unidad Estatal de Protección Civil de Colima