Report on Stromboli (Italy) — 23 January-29 January 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 January-29 January 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Stromboli (Italy). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 23 January-29 January 2002. Smithsonian Institution and US Geological Survey.
38.789°N, 15.213°E; summit elev. 924 m
All times are local (unless otherwise noted)
On 23 January at 2054 a large explosion occurred at Stromboli. The explosion was accompanied by a loud noise that was heard at all of the villages on the island and ashfall that lasted for several minutes. During a visit to the summit area on 24 January, INGV-CT staff found the area SE of the summit craters near Il Pizzo Sopra la Fossa between the Bastimento and La Fossetta was covered with ash and blocks. Most of the fallout was comprised of lithic material up to 60 cm in diameter, with minor amounts of spatter up to 1.7 m long. Fine-grained material covered the crater zone and the volcano's NE flank to the village of Stromboli, ~2 km to the NE. A continuous carpet of fallout material covered the zone of Il Pizzo, a spot where many tourists visit.
Weak volcanic activity was observed during the survey; only five weak explosions occurred from Crater 1 in 2.5 hours, with none at Craters 2 and 3. Thermal imagery showed that Crater 2 was hotter than the other active craters; the high temperatures were due to spatter coating the crater's inner walls. Measurements revealed that the diameter of Crater 2 had grown from an estimated 10 m in October 2001 to about 26 m after the 23 January explosion.
Geologic Background. Spectacular incandescent nighttime explosions at this volcano have long attracted visitors to the "Lighthouse of the Mediterranean." Stromboli, the NE-most of the Aeolian Islands, has lent its name to the frequent mild explosive activity that has characterized its eruptions throughout much of historical time. The small island is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The Neostromboli eruptive period took place between about 13,000 and 5,000 years ago. The active summit vents are located at the head of the Sciara del Fuoco, a prominent horseshoe-shaped scarp formed about 5,000 years ago due to a series of slope failures that extend to below sea level. The modern volcano has been constructed within this scarp, which funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild Strombolian explosions, sometimes accompanied by lava flows, have been recorded for more than a millennium.