GNSS measurements reveal unexpected far-field deformation of the 2023 Kahramanmaras earthquakes, Turkiye

Elastic dislocation models have been successfully used to model co-seismic displacements in numerous studies. Expected far-field displacements (>500 km) are low and most of the time beyond uncertainty level of the global navigation satellite system (GNSS) measurements. In the case of the moment magnitude 7.8 and 7.6 Kahramanmaraş earthquakes on 6 February 2023, the Türkiye’s extensive and continuous GNSS network allowed us to show that large earthquakes can induce far-field crustal deformations (>700 kilometers), exceeding current predictions from elastic dislocation models. This and the asymmetry of the co-seismic displacements with respect to the East Anatolian fault provides crucial insights about the deformation of Earth’s crust at various scales and the interactions among tectonic plates. It also carries profound implications for seismic hazard assessments and necessitates a new perspective on crustal deformation and earthquake mechanics.