Lithospheric strength variations and seismotectonic segmentation below the Sea of Marmara

The Sea of Marmara is a tectonically active basin that straddles the North Anatolian Fault Zone (NAFZ), major strike-slip fault separates Eurasian and tectonic plates. Main (MMF), which part NAFZ, contains an approximately 150 km long seismotectonic segment has not ruptured since 1766. A key question for seismic hazard risk assessment whether or next rupture along this likely to produce one earthquake series smaller earthquakes. Geomechanical characteristics such as along-strike variations in rock strength may provide important control on segmentation. We find lithospheric throughout region mechanical segmentation MMF help explain its long-term In particular, strong crust mechanically coupled upper mantle spatially correlates with aseismic patches, where bends changes strike response presence high-density lower crustal bodies. Between bends, weaker domains are decoupled from indicate predominance creeping. These results highly relevant ongoing debate regarding gap, especially view (Mw > 7) densely populated region. • 3-D thermal rheological models below Marmara. Due heterogeneous configuration, heterogeneities occur (MMF). Modeled consistent hypothesis segmented. seismogenic primarily controlled by crust.