Following my adventures in Tenerife, I took the opportunity to continue teaching about volcanoes at the Schools Science Festival, run at Durham University on 2nd-4th April. Along with several colleagues from the department, I helped to run practical sessions for year 9 and 10 pupils entitled “How to survive a volcanic eruption”.
We initially asked the pupils to think about what comes out of volcanoes and showed them some interesting examples of volcanic rocks, before starting them on their experiments. We challenged them with investigating how slope angle and viscosity affect the speed of a “lava flow”.
Of course, no real lava was available, so we simulated it with golden syrup, mixed with varying amounts of water to represent different viscosities. Each group was given a different viscosity “lava”, which they then poured down slopes set at different angles. A lot of the students observed that our “lava” travelled rather slowly – this is in fact realistic and shows that in reality, it is possible to outrun (or maybe even outwalk) a lava flow. The groups then plotted their results on our interactive chart, making the key observations that more viscous lava flows more slowly, and that steeper slopes lead to faster flows.
To give their findings a real world context, we then introduced the students to Ascension Island, a volcanic island in the Atlantic currently being worked on by masters students Annabelle Foster and Rebecca Winstanley. We asked the different groups to use what they had learned to draw on a map of the island where they would predict to be hit by lava flows during an eruption. Many sensibly predicted that the lava would travel down the steepest slopes, while some made the point that a larger eruption could in fact cover most of the island!
We then tested their ideas on our 3D cardboard model of Ascension, pouring syrup on the “erupting vent” and watching to see whether the lava would hit the position of the towns on the island. Each experiment produced different results, with some destroying two towns, and others destroying none. This ended up a rather realistic demonstration of the unpredictability of volcanic eruptions!
Overall our experiments were a great success and the sessions were enjoyed by pupils and event staff alike! On a personal note, I greatly enjoyed leading some of the sessions and I’m hoping to do more teaching and outreach, and inspire more people to study volcanoes in the near future.