Today, twitter is using the imaginative and inevitable #ashtag... Following the previous eruption near near Eyjafjallajökull, there was one under the glacial ice cap yesterday. This is problematic as it can melt the glacial ice causing an event called a jökullhaup. There is a report that the melt rate is 1000 m3/sec - that's an incredible 10m wide cube block of ice melting every second.
Each previous eruption here has been associated with a subsequent eruption of Katla, not far from Vík.
A jökullhaup is a violent rush of meltwater, and it can wipe landscapes clean. It scrapes the landscape flat and disrupt traffic around the south of Iceland for some time as the road needs to be rebuilt.
The Met Office say that by this evening, Ash should have reached Scandinavia and Southern England, with Scotland becoming clearer as the day proceeds. The red line on the map shows the limit of the risk of Ash between ground level and 20000ft, the green is from 20000ft to 35000ft, and red is from 35000ft and 55000ft. The latest advisories can be seen on the met office site, along with a description of the satellite technology used.
A nice sunset is predicted.