Stromboli: The 1985-1986 eruption

[ Full page view | Stromboli Home Page | Stromboli eruptive history | Main Index | Home Page ]

Stromboli volcano, Aeolian Islands (Isole Eolie), Sicily, Italy -- Eruptive history (1985-1995)

The 1985-1986 eruption

Map showing the lava flows of 1975 and 1985. From Bulletin of Volcanic Eruptions No. 27 (covering 1987)

Following the end of lava effusion in late November 1975, Stromboli did not emit any lava flows for exactly ten years, thus having one of its longest lava-free periods in this century. This was ended somewhat violently with an explosive crisis heralding the extrusion of lava from a new eruptive fracture below Crater 1 at 0800 on 6 December 1985. The initial explosive activity apparently had a strong hydromagmatic component (De Fino et al. 1988) and produced a dark, ash-laden eruption column that rose about 2000 m above the summit. At the same time, a small pyroclastic flow was observed (and photographed) while descending the Sciara del Fuoco (the photo has been published in Bulletin of Volcanic Eruptions No. 25, covering 1985, and in Barberi et al. 1993). Apparently there were no persons on the summit, and no damage was caused by the increased activity. The material forming the pyroclastic flow was mainly from the collapsed northeast rim of Crater 1.

Suggestive photograph of the December 1985 lava flow running down the Sciara del Fuoco. Precise date unknown. Photo scanned from a postcard, courtesy of Vincenzo Moreno (Edicola Cinefoto Sottile, Lipari).

Shortly afterwards, lava began to issue from the lowest part (at about 680 m elevation) of a new graben-like feature which developed on the northern end of Crater 1. The flow first descended northwards until reaching the wall of the Filo del Fuoco (the scarp bounding Sciara del Fuoco on its NE side), then it turned northwest and arrived at the sea during the late forenoon. A small peninsula was built where the lava entered the sea during the next two days; its remnants are still visible today. Sometimes, vigorous littoral explosive activity was observed at the lava entry points at the sea.

Only during the first week of the eruption did lava flow down all the Sciara del Fuoco to the sea; afterwards the flow was restricted to higher areas. A compound lava field with numerous distinct levee structures was formed in the course of the next several months. During April 1986, lava issued from ephemeral boccas between 600 and 550 m elevation and did not extend below 450 m elevation.

Explosive activity was rather weak during the period of lava outflow but became more vigorous after mid-April 1986, heralding the cessation of lava extrusion. Finally, strong phreatomagmatic explosions blasted out the effusive bocca at about 680 m altitude and Crater 1, leaving a deep chasm there. On 25 April 1986, all lava effusion ended, and very little activity occurred at Stromboli for about two weeks.

The usual Strombolian activity resumed on 5 May, and for the next months remained on a fairly normal level. It was during this period, however, that a fatal incident occurred at Stromboli. On 25 June 1986, a Spanish biologist who attempted to descnd into one of the craters was surprised by an eruption, and attempting to run for shelter, he fell and was hit by a bomb, dying instantly. This was the first fatality directly attributable to the eruptive activity of Stromboli since 1930.

Note that more info and some spectacular images of the 1985-1986 eruption are available at STROMBOLI ON-LINE (scroll down to "The lava flow of 1985/86").

Continue with 1986-1988: normal activity

Back to 1985-1995: The story in detail

Back to Eruptive history

Back to STROMBOLI home page Back to BB's volcano home page