Evolution of the Lava Flow Field by Daily Thermal and Visible Airborne Surveys

Abstract

On 28 December 2002, an effusive flank eruption started at Stromboli volcano (Aeolian Islands, Italy). This lasted until 22 July 2003 and produced two lava flow fields that were emplaced onto the steep slopes of Sciara del Fuoco. The first flow field was fed by a vent that opened at 500 m elevation and was active between 30 December 2002 and 15 February 2003. The second was supplied by a vent at 670 m and was emplaced mainly between 15 February and 22 July 2003. Here we review the lava flow field emplacement based on daily thermal and visual surveys. The variable slopes on which the lava flowed yielded an uncommon flow field morphology. This resulted in a lava shield in the proximal area where flow stacking and inflation caused piling up of lava due to the relatively flat ground. The proximal area was characterized by a complex network of tumuli and associated tube-fed flows. The medial-distal lava flow field was emplaced on an extremely steep zone. This area showed persistent flow front crumbling, producing a debris field on which emplaced lava flows formed lava channels with excavated debris levees. This eruption provided an exceptional opportunity to examine the evolution of lava flow fields emplaced on steep slopes and proved the usefulness of thermal imagers for safe and efficient monitoring of the active lava flows. In addition, thermal monitoring allowed calculation of quantitative parameters, such as effusion rate, allowing constraint of the time varying nature of supply to this eruption.