Report on Stromboli (Italy) — 14 March-20 March 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 March-20 March 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Stromboli (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 14 March-20 March 2018. Smithsonian Institution and US Geological Survey.
38.789°N, 15.213°E; summit elev. 924 m
All times are local (unless otherwise noted)
INGV reported that during 12-17 March activity at Stromboli was at normal levels, characterized by explosive activity and gas emissions from two vents (N1 and N2) in Area N and two vents in Area C-S (C and S2). Explosions at N1 ejected lapilli, bombs, and sometimes ash less than 120 m high, and less intense explosions at N2 emitted ash no higher than 80 m. The frequency of explosions in Area N was 3-8 events/hour. Continuous gas emissions rose from C. Explosions at S2 emitted ash no higher than 80 m at a rate of 2-5 explosions/hour. A high-energy explosive sequence began at vent C at 2027 on 19 March and lasted about 40 seconds. The first explosion ejected ash and incandescent material that fell in a radial distribution around the crater. Two subsequent explosions ejected incandescent material as high as 80 m. Tephra fell along the Sciara del Fuoco, towards the NE parts of the island. At 2028 an explosion at N2 ejected lapilli 100-120 m high.
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 from about 13,000 to 5000 years ago was followed by formation of the modern 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.