Location: NE Sicily, Italy
More than 25% of Sicily’s population live on Etna’s slopes, with Catania city at its base.
The Volcano: Active, composite (stratovolcano), formed by the Eurasian plate subducting beneath the African. 3350m in height and growing.
Key characteristics: Regular violent explosions and lava flows. Multiple active chambers, several craters, 300+ vents – Etna erupts from both summit & side vents.
Local Economy: Rich volcanic soils make the land fertile for olive groves, vineyards, citrus fruits and orchards. Piano Provenzano ski resort is on Etna.
July 2001... One of Etna’s largest recorded eruptions to date. Magma caused the volcano to bulge, resulting in earthquakes, followed by Strombolianstyle eruptions with ash, lava and volcanic bombs. Eruptions lasted for 24 days.
Impacts: Holiday villas, roads & buildings damaged (SOCIAL); Local vegetation & habitats destroyed (ENVIRONMENTAL); Catania airport closed due to ash; Orange groves & vineyards destroyed; farmland covered in ash; chairlift at ski resort damaged; ash fell in Catania (ECONOMIC). No deaths.
Response: Evacuation; US army dropped concrete to stop lava flow; cancelled holidays damaged the tourist industry; mass clean-up operation in Catania & surroundings; £5.6m aid from Italian government (SHORT TERM). Improved monitoring systems; better emergency planning; tourism used to boost economy; tax breaks given to locals to assist rebuilding; raised awareness of Sicily as a tourist destination (LONG TERM).
Post-2001: Etna has erupted annually but is well monitored and actively managed.
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.