A new collaborative study led by Turkish seismologist Süleyman Nalbant (Iğdır University), with contributions from Ian Main in the School of GeoSciences, reconstructs how stress built up and was released on the fault systems involved in the 6 February 2023 earthquakes in southeast Turkey (magnitude 7.8) and near Elbistan (magnitude 7.6). İskenderun, Hatay Turkey - February.06, 2023: In Iskenderun, one of the places most affected by the 7.7 magnitude earthquake centered in Kahramanmaraş On 6 February 2023, a magnitude 7.8 earthquake struck near the city of Kahramanmaraş in southeast Turkey, followed just nine hours later by a magnitude 7.6 quake near the town of Elbistan. Together, the two events caused widespread destruction and claimed over 60,000 lives.In a collaborative study led by Turkish seismologist Professor Süleyman Nalbant of Iğdır University, with contributions from Professor Ian Main in the School of GeoSciences, researchers reconstructed the build-up and release of stress along the region’s fault systems to understand why these earthquakes happened where they did.By analysing historical earthquakes dating back to 1822, the team found that the fault segment responsible for the initial magnitude 7.8 rupture had accumulated stress for over two centuries, making it critically primed for failure. The stress pattern on the day of the earthquake also explains why the rupture propagated at exceptionally high speeds on parts of the East Anatolian fault—a key factor in the intense ground shaking observed.The first earthquake then altered the stress on a nearby fault with a different orientation close to Elbistan, effectively “unclamping” it by releasing the pressure that had been holding it locked. This triggered the second large quake hours later, which also ruptured at unusually high speeds. This chain of events illustrates how one earthquake can set the stage for another, even on faults that initially appeared not to be under significant stress. Our study reveals that the devastating 2023 earthquake sequence was a complex, cascading process driven by a combination of long-term historical stress and immediate stress transfer. By updating models of stress evolution since 1822, we were able to show that the initial mainshock was far from a random event; it occurred in a region where stress had been building for centuries due to tectonic movement and previous earthquakes. Most significantly, our analysis of the Elbistan earthquake—the second major shock—demonstrates how a single event can 'unclamp' neighbouring faults, dramatically increasing the risk of subsequent large-scale ruptures. These findings underscore the vital importance of integrating both long-term and immediate stress loading into our hazard assessments to better anticipate and mitigate the risks of future multi-fault earthquake disasters. Professor Süleyman Nalbant Iğdır University This study highlights the importance of integrating historical earthquakes from the written archive and the geological record with instrumental recordings to estimate the stress field and to assess its role in influencing subsequent earthquakes. Ian Main Professor of Seismology and Rock Physics, School of GeoSciences Related links Read the full paper Publication date 01 Apr, 2026
