Report on Stromboli (Italy) — June 1986
Scientific Event Alert Network Bulletin, vol. 11, no. 6 (June 1986)
Managing Editor: Lindsay McClelland
Stromboli (Italy) Strombolian activity; small lava flows
Please cite this report as:
Global Volcanism Program, 1986. Report on Stromboli (Italy). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 11:6. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198606-211040.
38.789°N, 15.213°E; summit elev. 924 m
All times are local (unless otherwise noted)
. . . the Société de Volcanologie Genève (SVG) visited Stromboli in early April and observed continued lava production. On 3 April, two vents were active in the summit terrace. Strombolian activity at the main vent ejected tephra to 100-150 m height in explosions that occurred every 20-25 minutes. Explosions at 30-35-minute intervals from the second vent ejected only old material. An effusive vent in the upper NNE part of the Sciara del Fuoco (below and N of the main vent) quietly emitted two small lava flows. The main flow, ~1.5 m wide, moved N at ~0.5 m/s; its front was about halfway down the Sciara del Fuoco. The other flow was only 0.5 m wide and was moving more slowly, to the NNE. Activity the next day was similar, but the smaller lava flow had stopped advancing. On 5 April, Strombolian activity had declined; explosions were less frequent and tephra did not rise as far. One lava flow, ~2 m wide, was active, moving NNE at 1-1.5 m/s.
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, 924-m-high 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 from about 13,000 to 5000 years ago was followed by formation of the modern Stromboli edifice. The active summit vents are located at the head of the Sciara del Fuoco, a prominent horseshoe-shaped scarp formed about 5000 years ago as a result of the most recent of 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.
Information Contacts: P. Vetsch, SVG, Switzerland.