Etna volcano (Sicily): new lava analysis suggests volcano is changing behavior
Monday Apr 01, 2013 00:00 AM |
Sample of the White Lava erupted during the 16 Mar paroxysm (OPEC)
The usual black lava from Etna (sample from the 16 Mar paroxysm) (OPEC)
Analysis of the White Lava sample at OPEC
During a recent field trip in order to sample the lava erupted during the latest New SE crater paroxysm on 16 March 2013, members of OPEC (Osservatorio Privato Etneo di Catania) found, along with the usual basaltic black lava commonly erupted pieces of the extremely rare so-called "white lava" (see photo).
This white lava was first seen as occasional xenoliths during the excentric flank eruptions in 2011 and 2012, but never since until now. First macroscopic inspection revealed that it is a special variety of light-colored quartz-rich basalt, normally only produced by submarine volcanoes under certain circumstances (e.g. the restingolitas from the El Hierro 2011-12 La Restinga submarine eruption).
Geochemical analysis at the OPEC have further revealed a large Europium anomaly in the white lava. Europium, one of the rare earth elements (atomic no. 63, symbol Eu, atomic weight 151.96), is little known in its role in magmas, but it is suspected that enrichment occurs as a result of magma-sea water mixing.
Given the similarity of this lava to El Hierro's restingolitas, the current silence of Etna, along with the simultaneous strong seismic crisis at El Hierro, it is possible that some of Etna's magmas have been diverted through underground channels to El Hierro. Another hypothesis, to be confirmed, is that Etna might be undergoing a transformation towards becoming a predominantly submarine volcano, possibly reactivating old dikes such as those found along the Acitrezza-Acireale Ionian coast.
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http://www.volcanodiscovery.com/view_news/31775/Etna-volcano-Sicily-new-lava-analysis-suggests-volcano-is-changing-behavior.html
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