Stromboli is a persistently active volcano in the Aeolian Islands, Italy, with confirmed historical eruptions going back over about 2,000 years. The active summit craters on the crater terrace are situated above the Sciara del Fuoco, a steep talus slope on the NW side of the island that leads to the Tyrrhenian Sea below. The NE crater (Area N) includes the active N1 and N2 vents, while the Central and SW craters (Area CS) contains the C, S1, and S2 vents (figures 125 and 126).

Figure 125. False color thermal Sentinel-2 satellite image of Stromboli volcano with the locations of the Sciara del Fuoco and the active craters and vents. Four of the active vents are visible in this image as bright yellow-orange areas. Image acquired on 27 June 2018 and processed using bands 12, 11, 4. Courtesy of Sentinel Hub Playground.

Figure 126. Thermal image of the Stromboli crater terrace area showing the N (area N), and the central and S (area CS) craters with the active vents. Image taken by the Pizzo webcam, courtesy of INGV (report number 11/2018 for the period 5 to 11 March, released on 13 March 2018).

Typical activity comprises degassing and multiple explosions per hour that range from tens of seconds to a few minutes, known as Strombolian activity, which is named after this particular volcano (figure 127). The activity usually consists of low-intensity explosions that eject material (ash, lapilli, and blocks) up to 80 m above the crater and medium-low intensity explosions that eject material up to 120 m above the crater. This report describes the activity at Stromboli through March to June 2018 and summarizes reports published by the Istituto Nazionale di Geofisica e Vulcanologia (INGV).

Figure 127. The daily frequency of explosions per hour produced by all the active vents at Stromboli during the period 1 January to 2 July 2018. Red indicates explosions within the N crater, green indicates activity at the central-S craters, and blue indicates the number of total events. Courtesy of INGV (report number 27/2018 for the period 25 June to 7 July, released on 3 July 2018).

Characteristic Strombolian activity occurred throughout March, typically consisting of 5-11 events per hour that ejected material up to 120 m above the craters. High-energy explosive events occurred on 7 and 18 March, both lasting around 40 seconds and ejecting material to a height of 400 m (figures 128 and 129).

Figure 128. A high-energy explosive event on 7 March 2018 at the N2 vent of Stromboli. Top images (frames a to c) are thermal images, with the corresponding visible images across the bottom (frames d to f). Images were taken by the Pizzo webcams, courtesy of INGV (report number 11/2018 for the period 5 to 11 March, released on 13 March 2018).

Figure 129. Thermal infrared images of the high-energy explosive event on 18 March 2018 at Stromboli. The images show approximately 40 seconds of the explosive sequence recorded by the Pizzo webcam, courtesy of INGV (report number 12/2018 for the period 12 to 18 March, released on 20 March 2018).

Typical Strombolian activity continued through April with 6-12 explosive events per hour, with two high-energy explosive events on 24 and 26 April that lasted nine and three minutes, respectively. Both events ejected material across the Sciara del Fuoco, producing ash plumes and lava fountaining (figure 130). Low to medium-low intensity activity continued through May and June, with explosions per hour in the range of 3-15 and 6-13, respectively.

Figure 130. INGV noted an intense explosive sequence on 26 April 2018 at Stromboli. Top images (frames A to C) show the thermal signature of the explosion; bottom images (frames G to I) are the corresponding visible images. The sequence produced abundant ash, incandescent material, lava fountaining, and ejected large blocks to a height of 250 m above the vent that then fell around the crater and on the Sciara del Fuoco. Courtesy of the INGV (Blog INGVvulcani entry for 16 July 2018).

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.

Information Contacts: Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione di Catania, Piazza Roma 2, 95123 Catania, Italy (URL: http://www.ct.ingv.it/en/); Blog INGVvulcani, Istituto Nazionale di Geofisica e Vulcanologia (INGV) (URL: https://ingvvulcani.wordpress.com/2018/07/16/stromboli-e-le-sue-esplosioni/); Sentinel Hub Playground (URL: https://www.sentinel-hub.com/explore/sentinel-playground).