Geologic Background:
Mount Etna, towers above Catania, Sicily's
second largest city. Etna is Italy's highest and most
voluminous volcano and it has a history that is long and
complex. The oldest lavas, exposed on the lowermost
flanks of the volcano, erupted 300,000 years ago. Between
150,000-100,000 several volcanic centers coalesced and
calderas formed and filled. Between 65,000-25,000 years
ago a major vent grew to the southeast of the present
summit. Phreatomagmatic eruptions were common during this
period. Most of the summit of this volcano was removed by
subsequent caldera collapse. Between 18,000-5,000 years
ago four major volcanic centers continued to construct
Etna and three calderas formed. Valle del Bove is a
depression that formed about 5,000 years ago by gravity
sliding on the east flank of the volcano. Most of the
cones, craters, and pre-historic lava flows and tephra
deposits at the summit of Etna formed within the last
5,000 years.
Historic Activity:
- Etna has the longest record of historic eruptions.
The first recorded eruption was in 1500 B.C. Since then
Etna has erupted at nearly 200 times. Most of these
eruptions gentle effusion of lava or Strombolian
explosions.
- Historical lava flows cover much of the surface of
this massive basaltic stratovolcano.
Recent Activity:
- Since 1980 there has been nearly continuous activity
in the summit craters, with flank eruptions in 1984,
1985, 1986, 1991 to 1993, 1999, 2000, and 2001.
- Large flank flows in July-August 2001.
Data Sources:
- Smithsonian's SEAN Bulletin (V. 8, No. 3 to V. 14,
No. 12)
- Global Volcanism Network (V. 15, No. 1 to V. 26, No.
10)
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