Seismic Swarm S20251107.1 in Western Turkey

Western Turkey lies within one of the most seismically active regions of the Eastern Mediterranean, shaped by ongoing extensional tectonics in the Aegean domain. This area experiences frequent earthquake activity due to the interaction between the Anatolian Plate and the African and Eurasian plates, resulting in a network of normal faults that accommodate crustal stretching.

The swarm designated S20251107.1 was recorded in this setting, beginning at 06:59 on 6 November 2025 and concluding at 06:44 on 8 November 2025. Over 47 hours and 45 minutes, 58 earthquakes were registered. Event magnitudes ranged from 0.7 to 3.2, with the majority occurring at shallow depths between 2 and 13 km. A small number of events reached depths of 27 km. The sequence featured several events above magnitude 2.5, including peaks of 3.2, 3.1, 2.8, and 2.7, clustered primarily on 7 November.

Such swarms represent clusters of seismicity without a single dominant mainshock, often linked to fluid migration or stress redistribution along fault systems. In Western Turkey, these patterns align with the region's history of episodic low-to-moderate magnitude activity along graben structures.

Since 1 January 2000, only one prior swarm has been documented in the same internal classification framework, occurring in 2024. This limited occurrence underscores the relative rarity of swarm-type sequences compared to isolated tectonic events in the broader catalog.

Geological records indicate that Western Turkey has hosted destructive earthquakes throughout history, driven by the same extensional regime. Instrumental monitoring since the late 20th century has captured numerous events in the magnitude 5–7 range, though the current swarm remained well below thresholds for significant surface impact.

References
USGS Earthquake Hazards Program – Tectonic Summary of Turkey
European-Mediterranean Seismological Centre – Regional Seismicity Reports
Turkish Disaster and Emergency Management Authority (AFAD) – Historical Earthquake Database