Gas trapped beneath hydrate appears to result in the most concentrated hydrate deposits, perhaps because the gas that is held in the trap can slowly diffuse upwards or migrate through faults. With resivoir rock, the concentration of methane will be higher. Within these reservoirs, the methane in hydrate will be considerably more concentrated than conventional methane. Below that level, heat tends to keep the methane free in the form of gas. Under permafrost, hydrates may exist at subsurface depths of 130 to 2,000 meters.
Hydrates can cement loose sediments in a surface layer several hundred meters thick.
That might lead one to believe that hydrate stabilizes the seafloor. In fact, the reverse appears to be true. U.S. Geological Survey investigations indicate that gas hydrates may cause landslides on the continental slope. The answer begins with observation. Seafloor slopes of 5 degrees and less should be stable on the Atlantic continental margin.