On Friday last week I was asked to take this week's BBC Three Counties Radio Open University slot (15:45 Wednesdays) to talk about a spectacular but - so far - fairly harmless eruption of a volcano in southern Chile called Llaima. Today things have moved on. Llaima seems to be fairly quiet now, but a potentially more dangeous volcano in Ecuador called Tungurahua is possibly building towards a major eruption. Already 1000 people living nearby have been evacuated. Fine volcanic ash is raining down on their homes, and the Washington Volcanic Ash Advisory Center (which is responsible for the safety of aircraft flying nearby) as been churning out a series of warnings to pilots to avoid flying into clouds of ash that are drifting westwards from Tungurahua at at up to 27,000 ft.
If a jet aircraft flies into a cloud of volcanic ash, the engines can lose all their power, so this is a serious hazard. The drifting ash is unlikely to fall on the captial, Quito, which is 135 km north of the volcano, but it may reach the coastal city of Guayaquil, which, with over 2 million inhabitants, is more populous than Quito, as well as being Ecuador's major port. Ashfall poses a respiratory hazard, and can damage electrical and mechanical equiment. Heavy ash fall can make roofs collapse, or turn rivers into torrents of mud.
I'm hoping that I don't have a natural disaster to talk about on the radio on Wednesday, but only time will tell.
Footage of both volcanoes erupting can be found here (look in the Audio & Video column on the right).