Information on past seismicity of the western NAF system (Turkey) combining ground-motion models with historical earthquakes and event deposits recorded in the sediments of Lake Iznik (NAF system, Turkey)

The seismic chronicle, derived from the analysis of 14 short sediment cores and three long cores from Lake Iznik (NW Turkey), along with the identification of a subaquatic fault segment belonging to the Middle Strand of the North Anatolian Fault (MNAF), provides insights into both local seismicity and the regional seismic activity over the last 6000 years.

The integration of this seismic chronicle with ground-motion estimations at the core locations for all historical earthquakes, together with the evolution of sedimentation rate through time, allow to discuss the epicentral region and epicentral intensity of each historical earthquake in the western NAF system. This analysis also helps us to discriminate which earthquake is likely to generate an event deposit in the case of several historical earthquake candidate, especially when chronological uncertainty are larges

This approach allows a discussion of the factors influencing the threshold (sedimentation rate, ground motions at different spectral frequencies ) for triggering an event deposit in the Lake Iznik and the type of slope destabilization that can be triggered .

Thanks to these finding and through the established scaling relationship it is then possible to infer a minimum intensity for prehistoric earthquakes recorded in Lake Iznik at a given period.

Combining these data with paleoseismological data from the region allows us to propose a scenario for the long-term seismic cycle of the western NAF system.