Case study: Chances Peak, Montserrat, 1995-97 - an LEDC
Plymouth covered in ash from volcanic eruptions on Montserrat
Montserrat is a small island in the Caribbean. There is a volcanic area located in the south of the island on Soufriere Hills called Chances Peak. Before 1995 it had been dormant [dormant: A volcano is classed as dormant when it is temporarily inactive but not fully extinct. ] for over 300 years. In 1995 the volcano began to give off warning signs of an eruption (small earthquakes and eruptions of dust and ash). Once Chances Peak had woken up it then remained active for five years. The most intense eruptions occurred in 1997.
During this time, Montserrat was devastated by pyroclastic flows [pyroclastic flow: A very hot mixture of volcanic debris that flows downhill at high speeds. ]. The small population of the island (11,000 people) was evacuated [evacuated: When people have been removed or sent away from an area, usually for their own safety. ] in 1995 to the north of Montserrat as well as to neighbouring islands and the UK.
Despite the evacuations, 19 people were killed by the eruptions as a small group of people chose to stay behind to watch over their crops.
Volcanic eruptions and lahars [lahar: A destructive volcanic landslide or mudflow, consisting of a mixture of volcanic debris, mud, rock and water. ] have destroyed large areas of Montserrat. The capital, Plymouth, has been covered in layers of ash and mud. Many homes and buildings have been destroyed, including the only hospital, the airport and many roads.
The graphic shows the progress of the eruption and its impact on the island.
Montserrat - eruption progress and impact
Short-term responses and results
- Abandonment of the capital city.
- The British government gave money for compensation and redevelopment.
- Unemployment rose due to the collapse of the tourist industry.
Long-term responses and results
- An exclusion zone was set up in the volcanic region.
- A volcanic observatory was built to monitor the volcano.
- New roads and a new airport were built.
- Services in the north of the island were expanded.
- The presence of the volcano resulted in a growth in tourism.
Volcanic activity has calmed down in recent years and people have begun to return to the island.
You might be asked to consider the values and attitudes or opinions of people involved in the eruption, such as refugees or aid workers for example.
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Predicting volcanic eruptions
As a volcano becomes active, it gives off a number of warning signs. These warning signs are picked up by volcanologists (experts who study volcanoes) and the volcano is monitored.
|Warning signs||Monitoring techniques|
|Hundreds of small earthquakes are caused as magma rises up through cracks in the Earth's crust.||Seismometers are used to detect earthquakes.|
|Temperatures around the volcano rise as activity increases.||Thermal imaging techniques and satellite cameras can be used to detect heat around a volcano.|
|When a volcano is close to erupting it starts to release gases. The higher the sulfur content of these gases, the closer the volcano is to erupting.||Gas samples may be taken and chemical sensors used to measure sulfur levels.|
The techniques available for predicting and monitoring volcanic activity are becoming increasingly accurate. Volcanoes such as Mount St Helens in the USA and Mount Etna in Italy are closely monitored at all times. This is because they have been active in recent years and people who live nearby would benefit from early-warning signs of an eruption. However, as well as prediction, people need to be prepared for an eruption.