Geochemistry of Ash Leachates of The July-august 2001 Eruption of Mt. Etna Volcano
Abstract
Leaching analyses have been carried out on ashes deposited during the July-August 2001 eruption of Etna. Soluble salts coated on freshly erupted volcanic ash provide useful information both on magmatic components and on the composition of eruptive gases. Moreover soluble salts from ash clouds are released to the atmosphere and greatly influence the composition of rainwater expecially by increasing its acidity and ionic content. Previous authors have show that up to 33The July-August 2001 lateral eruption of Etna has been characterised by a strong explosive activity produced by a vent located in the south flank at 2550 m of altitude. This explosive activity has showed three phases: the phreatomagmatic opening phase (20-24 July), the magmatic phase (25-30 July) and the final phreatomagmatic phase (31 July-5 August). In both the first and final phases, tephra fallout were produced from impulsive ash jets superimposed on a continuos ash emission that formed a stable eruptive column high up to 2 km. It produced a widespread lapilli and ash fallout in the E-SE flank of the volcano that caused many civil defence problems, mainly to the Catania airport. 26 ash samples not exposed to rain were collected at the end of the first phreatomagmatic phase. Grainsize analyses of tephra collected along the dispersal axes have been performed at one-phi interval. An aliquot of 1 g of each granulometric class reacted with 25 ml of aQ grade Millipore water for 4 hours with constant agitation. Subsequently water was filtered and analysed for major element content (F, Cl, SO4, Na, K, Mg and Ca) by ionic chromatography.
- Publication:
-
EGS General Assembly Conference Abstracts
- Pub Date:
- 2002
- Bibcode:
- 2002EGSGA..27.5598B