|Recently, two destructive earthquakes (Mw 7.4, Mw 7.3) with 170-km of surface faulting devastated a large region of Western Turkey. Different international research groups have initiated preliminary studies but field data collection and analysis are needed. The RELIEF proposal consists of mainly field investigations in the epicentre area that aims to cover different disciplines from Pale seismology, Physics of the Source and Engineering Seismology. These large earthquakes represent a unique natural laboratory and the only opportunity to test our present understanding of the earthquake process and refine our current seismic-hazard models. These models are nowadays necessary for the development and application of seismic hazard approaches. Database collection will be disseminated by means of maps and reports (websites and GIS).