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Etna
photo gallery: 2003 |
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Part 3: July 2003 The
1614-1624 lava field ("Lava dei Dammusi"), 24 July 2003
The most voluminous and longest-lasting flank eruption of Etna during the historical period began in 1614 in the upper portion of the Northeast Rift and lasted for ten years, until 1624. The volume of lava emitted during that event is estimated at 1-2 cubic kilometers (compare this to the 0.02 and 0.03 cubic kilometers of lava of the 2001 and 2002-2003 eruptions, respectively), a volume similar to that emitted during the first twenty years of the ongoing Pu'u 'O'o eruption of Kilauea volcano in Hawaii. Seen on the geological map of Etna, the 1614-1624 lava flow-field is seen to cover a large fan-shaped area on the northern flank of the volcano; however, none of the numerous distal lava lobes extended into the inhabited and cultivated areas on the lower northern flank, and the eruption is not known to have caused any significant damage. The area of the lava field is given by Romano and Sturiale (1982) as 21 km2 with a maximum flow length of 6.5 km.
Yet,
besides its sheer size, the lava field of that eruption is one of the
most interesting among the hundreds of distinct lava fields on Etna.
Firstly, it is largely composed of pahoehoe lava (a Hawaiian word meaning
"one can walk barefoot on it", applied to lavas with a smooth,
wrinkled, or ropy, surface), and this type of lava surface is quite
rare at Etna. Secondly, the lava field presents a variety of peculiar
morphological features that give indications about the styles of lava
transport and emplacement during that eruption (these have been the
subject of a publication by Guest et al., 1984). Thirdly, like all lavas
erupted at Etna between 1600 and 1669, these lavas are rich in large
phenocrysts of plagioclase, which have led to the Sicilian name "cicirara"
- roughly translated as "pea lavas" (see photo below). And
last but least, the lava field contains several lava caves, the largest
of which are the Grotta del Gelo and the Grotta dei Lamponi. These caves
are nothing else than lava tubes, through which lava was transported
at low heat loss from the eruptive vents to areas further downslope,
in some cases extending over distances of several kilometers.
References: Guest JE, Wood C, Greeley R (1984) Lava tubes, terraces and megatumuli on the 1614-24 pahoehoe lava flow field, Mount Etna, Sicily. Bulletin Volcanologique 47: 635-648 Romano R (editor) (1979) Geological map of Mt. Etna. S.EL.CA. Firenze (distributed with volume 23 of the Memorie della Società Geologica Italiana, 1982, but out of print long since!) Romano R, Sturiale C (1982) The historical eruptions of Mt. Etna (Volcanological data). Memorie della Società Geologica Italiana 23: 75-97
Continue to September-October 2003 Return to the Etna photo gallery
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Copyright © Boris Behncke, "Italy's Volcanoes: The Cradle of Volcanology" | |||||||||||||||||
Page set up on 11 June 2003, last modified on 11 August 2003 |