A seismic swarm designated S20220829.2 was recorded in Sicily, Italy, from 23:31 UTC on 28 August 2022 until 13:40 UTC on 31 August 2022. Over 62 hours and 8 minutes, the sequence comprised 40 earthquakes, with magnitudes ranging from 2.0 to 3.5 and focal depths between 0 and 28 km. The events clustered in the late afternoon and evening of 29 August, when the largest shocks occurred, including a 3.5 magnitude earthquake at 18 km depth.
Sicily occupies a complex tectonic setting at the convergent boundary between the African and Eurasian plates. Ongoing collision and subduction processes along the Calabrian Arc drive regional seismicity, with the island also influenced by extensional tectonics in the Tyrrhenian Sea and volcanic activity at Mount Etna. Shallow crustal earthquakes, such as those in this swarm, are typical of the area’s active fault systems.
Historical records document major destructive events, notably the 1693 Val di Noto earthquake (estimated magnitude ~7.4) and the 1908 Messina earthquake (magnitude 7.1). Since 2000, only two prior swarms have been identified in the same internal classification: one event in 2011 and one in 2018. The 2022 sequence therefore represents a relatively infrequent but characteristic episode of clustered microseismicity.
The temporal distribution shows an initial event on 28 August followed by a rapid increase in activity on 29 August, peaking with multiple magnitude 3+ shocks within a two-hour window. Activity then declined steadily through 30 and 31 August. Depths were predominantly crustal, with several events located at or near the surface (0 km), consistent with tectonic release along shallow faults.
No damage or injuries were reported from this low-to-moderate magnitude sequence. Such swarms provide valuable data for refining seismic hazard models in a region where plate-boundary deformation continues to shape both seismic and volcanic risk.