Mass flows, turbidity currents and other hydrodynamic consequences of small and moderate earthquakes in the Sea of Marmara

Abstract. Earthquake-induced submarine slope destabilization is known to cause mass wasting and turbidity currents, but the hydrodynamic processes associated with these events remain poorly understood. Instrumental records are rare, this notably limits our ability interpret marine paleoseismological sedimentary records. An instrumented frame comprising a pressure recorder Doppler recording current meter deployed at seafloor in Sea of Marmara Central Basin recorded consequences Mw 5.8 earthquake occurring on 26 September 2019 4.7 foreshock 2 d before. The smaller event caused sediment resuspension weak (<4 cm s?1) water column. larger triggered complex response involving debris flow currents variable velocities orientations, which may have resulted from multiple failures. A long delay 10 h observed between passing strongest current. distance traveled by particles during estimated extended over several kilometers, could account for local deposit fan outlet canyon (where instrument was located), sedimentation did not likely cover whole basin floor. We show that after moderate earthquake, delayed initiation occur, possibly ignition cloud resuspended sediment.