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oa Submarine Landslides and Assessment of Slope Stability in Gas Hydrate Zones, Black Sea Region
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 18th International Conference Monitoring of Geological Processes and Ecological Condition of the Environment, Apr 2025, Volume 2025, p.1 - 5
Abstract
The Black Sea represents a distinctive geological and geochemical system, characterized by anoxic conditions, hydrogen sulfide accumulation, frequent gas venting, mud volcanism, and the formation of gas hydrates. The presence of gas hydrates and their dissociation could trigger slope failure, turbidites, and submarine landslides. To examine the instability in gas hydrate zones, an integrated analysis based on cruise data (R/V Mare Nigrum, cruise MN 249) is performed. During the cruise sediment cores were taken with a gravity corer from sites in the western part of the Black Sea. All cores were characterized by the presence of deep-sea sediments: sands, silt, sapropel, clays, and turbidite sediments. Geotechnical modeling was conducted using the OPTUM G2 software with two-dimensional finite element analysis (FEM). The modeling results indicate that gas hydrate dissociation leads to a decrease in effective stress, reducing soil strength, and potentially triggering slope instability. The model incorporated varying types of materials while accounting for critical physical and mechanical properties, such as soil cohesion, internal friction angle, type of model, and others. The maximum values of strains are observed on the boundary between silt deposits and turbidite complexes. The same trend is evident for the distributions of stresses. This study provides valuable insights for improving marine geohazard preparedness, reducing risks, and promoting sustainable practices in the Black Sea region.
