In the early hours of 2023, southeastern Turkey was rocked by one of the most powerful and unexpected earthquakes in recent history. Measuring a moment magnitude (Mw) of 7.8, the Kahramanmaraş/Pazarcik earthquake surpassed historical expectations for the region’s seismic activity and raised critical questions about how such ruptures initiate and propagate along major fault systems. Recent scientific investigations have now shed light on this natural disaster’s mechanics through an unprecedented analysis of near-field seismic data. This breakthrough not only deepens our understanding of earthquake dynamics but also has profound implications for future seismic hazard assessments worldwide.
The earthquake struck along the Narli splay fault—an important offshoot of the broader East Anatolian Fault system. While prior seismic records indicated moderate activity along this fault line, the Kahramanmaraş event defied conventional models by initiating an extraordinarily rapid rupture that eventually propagated onto the main East Anatolian Fault. This rupture progression raised a fundamental question among seismologists: how did the rupture accelerate so quickly and generate such destructive energy? To unravel this mystery, a team of researchers led by Rosakis, Abdelmeguid, and Elbanna undertook a meticulous examination of near-field ground velocity records, offering new insights into the rupture mechanics.
Fundamental to their analysis was the study of particle velocity data recorded by a dense network of seismometers situated close to the fault. These near-field recordings captured ground motions with exceptional temporal and spatial resolution, permitting an unprecedented look at the rupture process as it unfolded in real time. By examining the velocity pulses and waveforms, the researchers identified distinct phases in the rupture’s propagation speed that deviated markedly from the commonly assumed sub-Rayleigh speeds observed in many earthquakes.
One of the most striking findings from this study was clear evidence of an early transition from sub-Rayleigh to supershear rupture speeds along the Narli splay fault. Under normal circumstances, earthquake ruptures propagate at speeds slower than the shear wave velocity of the surrounding rock, known as sub-Rayleigh speeds. However, when rupture speed surpasses the shear wave velocity—becoming supershear—it produces seismic ground motions that are significantly more intense and destructive due to the generation of shock waves analogous to sonic booms in air.
The researchers estimated that the instantaneous rupture speed in the supershear regime reached approximately 1.55 times the shear wave speed. This rapid acceleration occurred shortly after rupture initiation, marking an early supershear transition that likely exacerbated the earthquake’s overall magnitude and damage footprint. Notably, the transition length from sub-Rayleigh to supershear rupture was calculated to be near 19.45 kilometers, underscoring how quickly and far rupture dynamics can shift within a complex fault network.
This evidence of supershear rupture is particularly remarkable because near-field, in-situ observational verification of such rapid rupture speeds has historically been challenging to capture. Most documented supershear earthquakes come from post-event seismic inversions or remote sensing, which often lack the granularity to pinpoint rupture initiation phases. Here, the researchers leveraged fine-grained velocity data to observe the rupture’s acceleration in real-world conditions, providing direct mechanistic validation for theoretical models of earthquake physics.
The implications of these findings extend beyond academic curiosity. Supershear ruptures generate seismic waves that not only travel faster but also produce a concentration of energy capable of causing more severe ground shaking and structural damage. This can amplify the risk to populations living near major fault zones that might previously have been considered lower risk based on historical seismic rates alone. Understanding when and where such supershear phenomena occur thus becomes critical for refining seismic hazard models and informing building codes and disaster preparedness.
Indeed, southeastern Turkey sits amid a complex tectonic intersection where the African, Arabian, and Eurasian plates converge, producing a labyrinth of interconnected faults. While conventional wisdom held certain fault segments to be relatively slow rupturing, the new research reveals that under the right stress conditions, accelerations to supershear speeds are possible even in less well-monitored regions. As such, the Kahramanmaraş earthquake serves as a wake-up call about the potential unpredictability and extreme behavior of fault ruptures in major seismic zones.
Additionally, the research highlights the indispensable role of near-field instrumentation in earthquake science. The placement of seismometers in close proximity to active fault lines allows for the capture of subtle but crucial ground velocity data that would otherwise be lost. This granularity provides the foundation for uncovering rupture speed transitions, displacement patterns, and energy release mechanisms that shape seismic hazard assessments.
The discovery also enriches our mechanistic understanding of earthquake rupture physics. The conditions that trigger supershear behavior—such as fault geometry, stress state, and rock properties—have long been theorized but rarely observed with empirical clarity. Here, the Narli splay fault’s geometry and regional stress regime helped facilitate the rupture’s acceleration past the shear wave speed threshold, aligning closely with theoretical models developed over the past decades.
Moving forward, integrating these findings into computational earthquake simulations could enable more accurate forecasts of rupture progression and associated ground motions. Advanced modeling efforts that incorporate the possibility of early supershear transitions may better replicate observed earthquake damage patterns, aiding emergency response planning and infrastructure resilience.
Moreover, this case study from Turkey adds to a growing global record of supershear earthquakes, sought after for both their scientific intrigue and hazard implications. Comparable events in California, Japan, and other tectonic hotspots have also demonstrated supershear phases, suggesting that such dynamics might be more common—and more impactful—than previously recognized.
From a societal perspective, awareness of rapid rupture acceleration calls for reassessment of preparedness strategies, particularly in urban centers situated near major fault systems. Early warning systems, engineering standards, and community education programs need to incorporate evolving scientific understanding to mitigate risks posed by these high-speed ruptures.
In the realm of seismology, the Kahramanmaraş earthquake represents a pivotal natural laboratory. The fruitful combination of dense seismic instrumentation, rigorous data analysis, and interdisciplinary expertise has provided a rare window into one of nature’s most violent and complex phenomena. By capturing the rupture’s real-time transition from sub-Rayleigh to supershear speeds, scientists have advanced both theoretical and practical knowledge of earthquake initiation and propagation.
Ultimately, the findings from Rosakis, Abdelmeguid, and Elbanna’s study underscore the critical importance of sustained investment in seismic monitoring infrastructure worldwide. Only through comprehensive data acquisition in near-field settings can the nuanced processes governing earthquake rupture be elucidated and integrated into hazard mitigation frameworks.
As seismic risks grow alongside expanding human populations and infrastructure, insights gleaned from the Kahramanmaraş earthquake will help refine our scientific toolkit and enhance society’s resilience against future seismic disasters. This landmark research not only improves our grasp of earthquake physics but also serves as a clarion call for proactive earthquake preparedness grounded in cutting-edge scientific observation.
Subject of Research: Earthquake rupture mechanics and supershear rupture propagation during the Mw 7.8 Kahramanmaraş/Pazarcik earthquake in southeastern Turkey.
Article Title: Near-field evidence for early supershear rupture of the Mw 7.8 Kahramanmaraş earthquake in Turkey.
Article References:
Rosakis, A., Abdelmeguid, M. & Elbanna, A. Near-field evidence for early supershear rupture of the Mw 7.8 Kahramanmaraş earthquake in Turkey. Nat. Geosci. 18, 534–541 (2025). https://doi.org/10.1038/s41561-025-01707-2
Image Credits: AI Generated
