Seismic Swarm S20240125.2 in Eastern Turkey
Eastern Turkey occupies a tectonically complex zone at the convergent boundary between the Arabian and Eurasian plates. This collision drives ongoing deformation along major structures such as the East Anatolian Fault Zone and the Bitlis-Zagros suture, producing predominantly strike-slip and thrust faulting. The region experiences frequent seismic activity, with historical records documenting destructive events that have shaped both the landscape and settlement patterns over millennia.
Swarm S20240125.2 was recorded in this setting between 21:31 UTC on 24 January 2024 and 15:40 UTC on 28 January 2024. The sequence lasted 90 hours and 9 minutes and comprised 62 earthquakes. Depths were predominantly shallow, clustering near 7 km, with isolated events reaching 16 km. Magnitudes remained low to moderate except for a peak event of M5.0 at 13:04 on 25 January, located at 16 km depth. Subsequent activity included events of M3.4 and M3.3 within the first day, followed by a gradual decline in both rate and size.
The temporal distribution shows an initial burst of small events, a rapid escalation coinciding with the M5.0 shock, and a prolonged tail of micro-earthquakes. Depths stayed consistent around 7 km for most aftershocks, suggesting activation within a shallow crustal volume. This pattern aligns with swarm behavior driven by fluid migration or aseismic slip rather than a single mainshock-aftershock cascade.
Since 1 January 2000, four swarms have occurred in the same area. The earliest documented swarm took place in 2023, indicating that clustered seismicity is a recurring feature of the local fault network. Such episodes contribute to the cumulative strain release along the plate boundary without producing large, damaging ruptures.
Continued monitoring of these swarms provides valuable data on fault interactions and stress transfer in one of the most active segments of the Alpine-Himalayan belt. Understanding their characteristics supports improved seismic hazard assessment for communities in eastern Turkey.
References
- United States Geological Survey Earthquake Catalog
- SeismoSight internal swarm classification records