Seconds for Istanbul: prediction of earthquake ground motion

The megacity Istanbul, the economical capital of Turkey, with more than ١٠ million inhabitants is exposed to a significant earthquake risk since the level of groundmotion due to a possible earthquake in this area and the vulnerability of the building stock are high. Therefore, several projects have focused their attention on the estimation of seismichazard and seismic risk for Istanbul. Among others, the CEDIM: Megacity Istanbul project, the SAFER (Seismic eArly warning For EuRope), and EDIM (Earthquake DataInformation system for the Marmara Sea, Turkey) contributed to improve seismic hazardassessment. In particular the application of the microzonation method allows both the estimation of the fundamental resonance frequency, and of soil velocity profiles by means of usingseismic noise analysis. The results highlight areas that might be prone to ground motion amplification. The SAFER and EDIM projects allowed the development and installation of an innovative Self-Organising Seismic Early Warning Information Network (SOSEWIN)that also allows for monitoring of the vibration characteristics and dynamic properties of strategic civil infrastructures, as validated by performing tests on the Fatih SultanMehmet Bridge. With our improved knowledge a realistic earthquake scenario with strong ground motioncan be derived, as a basis for predicting such movement during an earthquake and with the help of an early warning system the people of Istanbul can be warned before the strong S-waves arrive.