Report on Stromboli (Italy) — 22 March-28 March 2023
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
22 March-28 March 2023
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2023. Report on Stromboli (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 22 March-28 March 2023. 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 both explosive and effusive activity at Stromboli occurred during 20-26 March, though inclement weather conditions prevented views on most days. Activity was centered at three vents in Area N within the upper part of the Sciara del Fuoco, and from four vents in Area C-S (South-Central Crater) on the crater terrace. Explosions at two vents in the N1 crater and one vent in the N2 crater in Area N were low to medium intensity and ejected coarse material (bombs and lapilli) 80-150 m at a rate of 6-12 explosions per hour. Explosive activity at three active vents at the S2 sector in Area C-S ejected coarse material generally as high as 150 m above the vent at a rate of 5-7 explosions per hour; material was ejected as high as 300 m on 23 March. Sector C was characterized by occasional low-intensity explosive activity through the week and intense spattering on 22 March. No activity was recorded at sector S1. A strong explosion at 1549 on 25 March at Area C-S and was followed by two minor explosions; the sequence lasted about three minutes.
A lava overflow event at one of the N1 vents began at 2242 on 23 March and was preceded by spattering activity in Area N. After about an hour lava flowed along the Sciara del Fuoco in the ravine that had formed in October 2022. The flow rate notably increased during 0200-0400 on 26 March and caused avalanches of material from collapses at the advancing flow front. By that afternoon the flow was cooling down and no longer being fed. It was unknown due to weather conditions if material reached the coastline.
Geological Summary. Spectacular incandescent nighttime explosions at Stromboli have long attracted visitors to the "Lighthouse of the Mediterranean" in the NE Aeolian Islands. This volcano 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 scarp that formed about 5,000 years ago due to a series of slope failures which extends 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.