Mt Etna is a active volcano that rests on the boundary formed between the Eurasian and African plates. As the African plate subducts, magma from the mantle rises up through cracks and fissures on the plate to form like Mt Etna. Mount Etna rises over 3300 m to dominate eastern Sicily. Its activity has been recorded for over 2500 years, making it one of the best documented volcanoes on Earth. It lies in a major earthquake zone, and volcanic eruptions are often accompanied or punctuated by earthquakes.
EFFECTS of the eruption in 2001:
· Clouds of pyroclastic gas and ash from two vents.
· Magma thrown 100m into air.
· Lava runs down volcano side in two separate flows.
· 1000 people had to leave their homes and many schools were shut down.
· The airport in Catonia was closed for 4 days because the ash covered the runway and clogged aeroplane engines.
· The skiing season was disrupted with three lifts being damaged and a restaurant engulfed in ash.
· Hundreds of acres of forest on the slopes of the volcano were destroyed.
· The earthquake damaged more than 100 homes in Santa Venerina.
· 300 businesses affected by the eruption.
Predictions, Mitigations and Responses:
· Holiday homes were taken over by local authorities to house the homeless people.
· The town of Linguaglossa was evacuated before the eruption because of the lava flows.
· The Italian government declared a state of emergency in pats of Sicily during the eruption.
· Scientists diverts the flow of lava away from their research centre at the base of the volcano.
· The army cracked the tarmac in an attempt to divert the lava away from populated areas.
· A ship equipped with a medical clinic was positioned off Catania to be ready in case of emergency.
· The Government gave tax breaks to villagers to help them get through the crisis.
· More than $8m (£5.6 million) was given by the Italian government for immediate financial assistance
- The government planned a disaster response in advance of the eruption in order to save the lives of people living near the danger zone. The below responses and measures were taken for the 1971 eruption except, for the last measure below that was enabled for the 1991-1993 eruption.
- The Italian Air Force took aerial photographs of the summit as a prelude to the eruption. These photographs provide a base upon which the main geographical features were mapped.
- The government was looking for flank eruptions, rather than a summit eruption, which are known to cause considerably more damage.
- Scientists were able to measure the depth of the Mt. Etna to determine the amount of lava filling the central crater.
- The rumblings and sounds were closely monitored as increased sounds may lead to an imminent explosion or crack in the fissure leading to a lava flow.
- Ground temperature measurements were made. A rise in temperature could indicate a location of a build-up of magma below the central crater.
- Other, more non-scientific measures include: orderly evacuations where necessary, brisk mobilization of aid and rapid restoration of communications.
- Diversion of the lava flow with the construction of earth barriers built perpendicular to the lava flow can save threatened areas.
The 2002 eruption of Mount Etna, Italy, resulted a light ash fall in Catania (3 mm). The light
dusing of ash nevertheless adhered to the skin of citrus, which rendered fruit unfit for juice production because it was not economically feasible to separately clean each fruit before processing.
Ash from Etna volcano on the surface of citrus fruit made it uneconomical to produce juice because it was too expensive to clean the fruit (image courtesy of La Sicilia).
Rainfall interacting with volcanic gas within the ash plume may produced acids which fall as acid rain. Continued degassing at the vent may lead to ongoing acid rain even after ash fall ceases.
The acidity and nature of the ash (and leachates derived from the ash) varies between volcanoes and eruptions. Ash falls can lead to elevated soil sulphur levels and lowered soil pH. These changes in soil composition can reduce the availability of phosphate and other essential minerals and alter the soil's characteristics to such an extent that arable crops and pasture plants will not survive. Where there is acid rain following an eruption, pastures will be scorched and die.