********************************************************************* New summit eruption at Mount Etna Istituto Nazionale di Geofisica e Vulcanologia ? Sezione di Catania ********************************************************************* From: Sonia Calvari <calvari@xxxxxxxxxx> At 23:30 local time on 14 July 2006, a fissure opened on the east flank of the South-East Crater (SEC) summit cone of Mt. Etna. Two vents along the fissure produced a lava flow spreading east to the Valle del Bove. A helicopter survey carried out on 16 July at 7:30 showed a braided lava flow field up to 1.7 km long. Mapping of the lava flow field allowed a calculation of its surface area and approximate volume, leading to an estimation of a mean output rate of about 2.6 cubic meters per second during the first 32 hours of eruption. Moderate strombolian activity from a third upper vent, located at about 3100 m on the east flank of the SEC, just below the wide depression that cuts its eastern flank, produced a little ash fallout on Catania during the opening phase of the eruptive fissure. The composition of the ash was 80% juvenile, with small amount of lithics probably due to the opening phase of the vents. The lava flow field emplaced on the west wall of the Valle del Bove, with two main flow fronts that, at 7:30 of 17 July, reached about 2100 m a.s.l. spreading north of the Serra Giannicola Piccola ridge. The lava flow field emplacement reached a peak on 20 July, when an effusion rate of about 10 cubic meters per second allowed the lava flow to reach a maximum distance of about 3 km within the Valle del Bove. The lava flow front widened at the base of Monte Centenari, at 1800 m a.s.l. and at least 15 km distance from the closest villages. The effusion rate on 23 July decreased to about 3 cubic meters per second, with the lava channels narrowed and levees partially collapsed. The eruption finished on 24 July. Today 26 July, strong explosions were heard from the rim of the North- East Crater, and lapilli fell on the crater rim. This crater, together with the south pit within Bocca Nuova, were showing significant thermal anomalies during a helicopter survey carried out on 24 July. Sonia Calvari ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
