Effect of crossflow on trapping depths of particle plumes: laboratory experiments and application to the PLUMEX field experiment

The fate and transport of sediment plumes in the ocean, such as those resulting from the disposal of deep-sea mining residuals, are affected by ambient crossflow. We present laboratory measurements of the depth at which a particle plume is trapped by ambient stratification for various crossflow and particle settling velocities. Results suggest that the trap depth declines exponentially with crossflow velocity but is relatively insensitive to settling velocity in the range studied. An empirical correlation based on the laboratory data is validated by a larger scale field experiment involving simulated disposal of deep-sea mining wastes.