Dike emplacement at Mount Etna before the 2002 flank eruption revealed by surveys with a portable thermal camera
Abstract
The use of the thermal camera has been applied to routine monitoring of Etna volcano since August 2001, when the FLIR TM695 device became available to the INGV Section of Catania. The thermal camera soon became essential to volcano monitoring, because it is the only system allowing detection of the volcanic activity through the curtain of gases that usually obscures the craters. The thermal camera has allowed us to detect morphology changes of the summit craters caused by paroxysmal explosions, dispersal of erupted products, and magma level within the summit craters. Routine measures with a thermal camera have shown the development of hot fractures on the inner walls of Bocca Nuova crater and their evolution into rock falls and ash emission, as well as instability of cinder cones recently developed on the upper reaches of the volcano. The most important result was obtained between February and June 2002, when helicopter-borne thermal images showed the opening of a field of fractures expanding from the NE-Crater to the SE-Crater. This growing field of fractures eventually formed the fissure system feeding the 2002 flank eruption, which started on 27 October 2002 and is still going on as on January 13, 2003. Dike emplacement into the upper part of the volcano has been detected through thermal measurements several months in advance. Especially when seismic swarms do not help in forecasting eruptions because they are preceding an eruption of just a few hours, this new monitoring technique, if used regularly on a volcano, proved to be essential.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....5329C