Civil Protection: risk of eruption, orange alert for Stromboli volcano

John

By John

Orange alert for the Stromboli volcano due to the reports and hazard assessments made available by the National Institute of Geophysics and Volcanology, the Cnr-Irea and the Universities of Florence, Palermo, Pisa and Turin. The Civil Protection Department announced this in a note.

The alert level goes from yellow to orange after the assessments that emerged during the meeting with the Competence Centers and the bodies of the Region, which was also attended by the mayor of Lipari Riccardo Gullo. “The mayor – we read in the note – will be constantly informed on the evolution of the situation in order to be able to guarantee constant information to the population, who are recommended to follow the indications provided by the local authorities”.

The statement

Yesterday evening, the Department of Civil Protection ordered the passage of alert for the Stromboli volcano from the yellow level to the orange level. The meeting was called following the volcano’s activities, namely an eruptive phase that began on Sunday with a lava overflow on the Sciara del Fuoco, frequent explosions in the southern crater area and an increase in the average amplitude of volcanic tremors.

The passage of the alert level is based on the reports of the phenomena and on the hazard assessments made available by the Competence Centers, which for Stromboli are the National Institute of Geophysics and Volcanology (Etnean Observatory, Vesuvius Observatory and Palermo Section), the CNR-IREA and the Universities of Florence, Palermo, Pisa and Turin.

Raising the alert determines the strengthening of the volcano monitoring system and the information connection between the scientific community and the other components and operational structures of the National Civil Protection Service. The Department of Civil Protection shares this information with the civil protection structure of the Sicilian Region which, especially in relation to local impact scenarios, alerts the territorial civil protection structures and adopts any measures in response to emergency situations.
The Mayor of the Municipality of Lipari, who took part in the meeting, will be constantly informed on the evolution of the situation in order to guarantee constant and correct information to the population.

Regardless of the local level volcanic phenomenologies, which can have frequent variations, a situation of enhanced disequilibrium of the volcano persists. The population on the island is therefore invited to keep informed and scrupulously follow the instructions provided by the local civil protection authorities.

Stromboli

Stromboli – as stated on the Civil Protection website – is one of the seven islands that make up the Aeolian archipelago. It is considered one of the most active volcanoes in the world, given its persistent eruptive activity with an open conduit, called “Strombolian”. In fact, every 10-20 minutes, moderate-energy explosions occur, with the launch of shreds of incandescent lava, lapilli and ash up to a few hundred meters high. The explosions originate from several vents, aligned in a north-east south-west direction, located inside a crater terrace at about 700m above sea level in the upper part of the Sciara del Fuoco, one of the slopes of the volcano.

In addition to the explosive activity, known as “ordinary”, the craters are periodically affected by other types of explosions: “major” and “paroxysmal”. Major explosions can occur several times a year and can cause heavy materials – blocks of rock and volcanic bombs – to fall into the upper part of the volcano; while “paroxysmal” explosions have a return period of a few years and can launch heavy materials over a greater distance, also affecting lower altitudes, and even reaching inhabited centers, as happened during the eruption of April 5, 2003. Sometimes, explosive activity can give way to lava flows that pour down the Sciara del Fuoco.

Eruptive phenomena, in particular lava flows and paroxysmal explosions, can destabilize the slope of the Sciara del Fuoco, causing landslides that involve the emerged and/or submerged parts of the structure. Landslide events can also trigger tsunamis with effects along the coasts of the island itself, as well as Panarea and possibly the other Aeolian islands, Calabria and Sicily.

Finally, explosions of greater energy can create risky conditions both in the upper part of the mountain and, to a lesser extent, in inhabited areas. There are two inhabited centers on the island: Stromboli and Ginostra, located respectively in the north-eastern and south-western sectors.