The 16 August 2010 earthquake in the Aeolian Islands (Sicily)
At 12.54 h UTC (14.54 local time) on 16 August 2010, the southern portion of the Aeolian Islands has been shaken by a magnitude (Mw) 4.5 earthquake, which caused rockfalls and landslides on the steep rocky coasts in the south part of Lipari island and in the north part of Vulcano island. The epicenter was located a little to the west of the northern part of Vulcano, the focal depth was estimated at 12-14 km.
This earthquake occurred in the context of one of the most important fault systems of the central Mediterranean, which runs across northeastern Sicily, from the Ionian Sea to the Tyrrhenian Sea, and across the Aeolian archipelago up to the Secca del Capo to the north of the island of Salina. The system is characterized by transcurrent movements, and has been the source of numerous historical earthquakes. The most important earthquake in recent time on this structure occurred on 15 April 1978 (M 6.1, epicenter in the Gulf of Patti), about 30 km south of the epicentral location of the 16 August 2010 earthquake.
Other recent M ~4 events in the aforementioned zone of transcurrent tectonics, about 20 km south of the 16 August 2010 epicenter, occurred on 27 October 2008 (Ml 4.0 and shallow hypocentral depth), and 27 February 2006. Previously, a M=4.7 earthquake had occurred on 5 aprile 2002. Closer to the 16 August 2010 event, another event of similar magnitude, had occurred on 18 August 2007, which was characterized by a transcurrent focal mechanism, and a focal depth of about 8 km.
More significant earthquakes have occurred in the same zone historically, without, however, producing any disastrous effects.
The 16 August 2010 earthquake was widely felt in eastern Sicily, to as far south as Siracusa; it was most strongly felt in the southern portion of the island of Lipari. Here, the earthquake caused anxiety in the population and provoked very slight structural damage to buildings in the town of Lipari, as well as damaging stone walls along roads that were already unstable. Furthermore, the earthquake provoked several landslides and rockfalls due to the collapse of the steep rocky coasts in the southwestern part of the island, in the area between the Valle Muria beach and the rock islets below Contrada Falcone. Analogous phenomena occurred also on the southeast coast at Punta di Capistello. From a macroseismic point of view, in the south part of Lipari, the earthquake reached an intensity of V-VI on the MCS scale.
On the island of Vulcano as well as on the Tyrrhenian coast of Sicily between Oliveri-Tindari and Milazzo, the earthquake was strongly felt and accompanied by a loud rumbling noise, causing oscillations of hanging objects, and in some cases made objects fall on the upper floors of buildings. In this area, the macroseismic intensity reached grade V on the MCS scale.
The main shock was followed by a few aftershocks of minor magnitude during the following days.
Automatic monitoring and field observations in the geothermal areas on the island of Vulcano, in particular the Fossa cone and the extensive fumarole field in its crater, reveal no significant variations in the geochemical parameters (thermal aquifers, fumaroles), fumarole temperatures, ground deformation, and the thermal output of the Fossa crater, neither before nor after the 16 August 2010 earthquake.