Describe how volcanoes are monitored so that people can prepare for an eruption.

Volcanoes often show precursory activity before they erupt. Volcanologists can monitor this activity to forecast an eruption.

This includes:

- Monitoring earthquakes with seismometers. Just before an eruption, lots of small earthquakes occur due to magma rising up inside the volcano.

- Measuring the temperature of the volcano using thermal images. As volcanic activity increases, so does the temperature of the volcano.

- Monitoring sulphur dioxide concentration in volcanic gases. Before an eruption, volcanoes release a lot of gas, particularly sulphur dioxide.

 

Volcanologists use all these techniques together to get a better understanding of the volcano's activity.