Dynamics of deep-submarine volcanic eruptions.

Deposits from explosive submarine eruptions have been found in the deep sea, 1-4 km below the surface, with both flow and fall deposits extending several km's over the seafloor. A model of a turbulent fountain suggests that after rising 10-20 m above the vent, the erupting particle-laden mixture entrains and mixes with sufficient seawater that it becomes denser than seawater. The momentum of the resulting negatively buoyant fountain is only sufficient to carry the material 50-200 m above the seafloor and much of the solid material then collapses to the seafloor; this will not produce the far-reaching fall deposits observed on the seabed.