The Universidad de Colima reported that a large explosion at Colima was recorded at 1732 on 3 February, generating an ash plume that rose 6 km above the crater rim and drifted SSW. A small pyroclastic flow traveled down the E flank. The report stated that the internal crater is about 250 m in diameter and 50-60 m deep; previous lava domes had been destroyed in late September and mid-November 2016. On 9 February the sulfur dioxide gas flux was low (19 tons/day). Based on webcam and satellite images, the Washington VAAC reported that on 11 February an ash plume rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted W. On 14 February an ash plume rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted NE.

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), Centro Universitario de Estudios Vulcanológicos (CUEV) - Universidad de Colima