Citation

Nasıf A, Dondurur D. Geo Marine Lett. 2021; 41(1): 16.

Copyright

(Copyright © 2021, Springer-Verlag)

DOI

10.1007/s00367-021-00688-6

PMID

unavailable

Abstract

Multi-channel seismic, 3.5-kHz Chirp seismic, and multibeam bathymetric data were collected along the western Black Sea margin, offshore Sakarya River, to investigate the morphology and to evaluate the potential geologic hazards. The multibeam bathymetric data show that the morphology of the margin is controlled by the Sakarya Canyon consisting of three distinct canyon heads, all incising the southern continental shelf. Deep-water sediment erosion along the canyon walls and scour marks along the distal canyon floors indicate that both Sakarya and Kefken Canyons may be active in terms of sediment erosion and turbidity currents. We identify the depositional and erosional features in the area by means of echo-character mapping. The distribution of different echo-types is mainly controlled by the morphology of the margin, as well as the shape, location, and structure of the major canyon systems. Erosional features, constituting 47% of the total surficial area, are classified as slides, erosional truncations, gravitational mass wasting, gullies, and outcropping seafloor while depositional features, constituting 53% of the total surficial area, comprise shelf sediments, turbidites, pelagic/hemi-pelagic sediments, and sediment waves. Different types of geohazards coexist along the Sakarya Canyon, which are classified as hazards linked to (1) local and/or regional tectonism, (2) morphology of the continental margin (turbidity currents, slope overstepeening), and (3) prevailing sedimentary processes (mass transports, submarine fluid flow, loss of support due to the truncation scarps and bedforms).

Language: en