Gas hydrates have been of interest for years, but as of late they have become increasingly considered as a potential energy source, a potential environmental impact, and a geohazard. This paper discusses the latter. A simple model was developed to analyse the impact of gas hydrate dissociation on the stability of submarine slopes as described by the factor of safety. Dissociation of gas hydrates will result in the release of large quantities of gas, which in undrained conditions will cause significant increase in the pore pressure, decrease in effective stress, and could ultimately result in soil failure. The model considers the water depth, seabed temperature, geothermal gradient, and quantity of gas hydrate as well as soil parameters such as void ratio and plasticity index. Results indicate that dissociation of even a relatively small percentage of gas hydrates can have a significant impact on the stability of a submarine slope. Further, the analysis shows that slopes located at shallower water depths will be more susceptible to instability due to hydrate dissociation.
A simple model for submarine slope stability analysis with gas hydrates