Analysis of ca. 1400 km of multichannel seismic data indicate that the distal part of the Sakarya Canyon within the continental rise is an unstable region with sediment erosion. Fourteen buried debris flows (DB1–DB14), in the stacked form within Plio–Quaternary sediments between 1400 and 1950 m water depth, were observed in the surveyed area. Their run-out distances range from to km. The largest debris flow DB10 affects ca. 225 km2 surficial area transporting ca. 15 km3 of sediment in S to N direction. | Turkish Journal of Earth Sciences Turkish J Earth Sci 2021 30 247-267 http earth TÜBİTAK Research Article doi yer-2008-2 Stacked debris flows offshore Sakarya Canyon western Black Sea morphology seismic characterization and formation processes Derman DONDURUR1 Aslıhan NASIF1 2 1 Institute of Marine Sciences and Technology Dokuz Eylül University İzmir Turkey 2 The Graduate School of Natural and Applied Sciences Dokuz Eylül University İzmir Turkey Received Accepted Published Online Final Version Abstract Analysis of ca. 1400 km of multichannel seismic data indicate that the distal part of the Sakarya Canyon within the continental rise is an unstable region with sediment erosion. Fourteen buried debris flows DB1 DB14 in the stacked form within Plio Quaternary sediments between 1400 and 1950 m water depth were observed in the surveyed area. Their run-out distances range from to km. The largest debris flow DB10 affects ca. 225 km2 surficial area transporting ca. 15 km3 of sediment in S to N direction. The debris flows in the area are considered as gravity flows of unconsolidated sediments mobilized due to the excess pore pressures occurred in the unconsolidated shallow sediments arising from the high sedimentation rate. We also suggest that extensive seismic activity of North Anatolian Fault NAF located ca. 140 km south of the of the study area along with the possible local fault activity is also a significant triggering factor for the flows. The stacked form of the debrites indicates that the excess pore pressure conditions are formed periodically over the time in the continental rise which makes the region a potentially unstable area for the installation of offshore engineering structures. Key words Western Black Sea Sakarya Canyon debris flow seismic reflection excess pore pressures 1. Introduction Submarine slump and slides occur as a result of sudden Continental slopes are the areas .
