Volcanoes
Composite and shield volcanoes are found along plate margins. They have distinctive characteristics and can have both positive and negative effects on people and the landscape.
Monitoring volcanoes - popular techniques
A Willmore seismometer monitors earthquakes
Volcanic eruptions are unpredictable. However, scientists can monitor volcanoes to estimate when they are likely to erupt. Scientists can use a variety of techniques to do this, such as:
- seismometers - used to measure earthquakes occurring near an eruption
- tiltmeters and GPS satellites – these devices monitor any changes in landscape. Volcanoes tend to swell near an eruption
- monitoring gases escaping from a volcano using robots called Spiders – often there is an increased release of sulphur dioxide near an eruption
- measuring temperature - volcanoes become hotter when magma starts to rise through the main vent
- looking at the past history of eruptions - scientists can identify patterns of activity