Undated image of Cerro Machín in Colombia.
I just picked up on this story over on the Volcanism Blog, but I want to post it here too. Machín, in Colombia, has experienced a sharp increase in seismicity at the volcano – maintaining the Yellow status for the volcano. 54 earthquakes were recorded at the volcano over the weekend, prompting the INGEOMINAS to raise the alert status. The volcano had a swarm in 2008 that did not lead to any eruption – but remember, better to be safe than sorry. If Machín were to erupt, it would join Galeras and Huila as erupting volcanoes in Colombia.
Not much is known about Machín, located only 22 km / 14 miles from the city of Ibagué (pop. ~500,000). The last known eruption (well, dateable eruption) was in ~1180 A.D. (+/- 150 years) and over the last 4,000 years, the volcano has produced at least seven eruptions. Typically they are explosive events, producing ash falls, pyroclastic flows and lahars – par for the course for the Colombian volcanoes.