<< In certain parts of the ocean, towering, slow-motion rollercoasters called internal tides trundle along for miles, rising and falling for hundreds of feet in the ocean's interior while making barely a ripple at the surface >>
<< Internal tides are generated in part by differences in water density, and created along continental shelf breaks, where a shallow seafloor suddenly drops off like a cliff, creating a setting where lighter water meets denser seas. In such regions, tides on the surface produce oscillating, vertical currents, which in turn generate waves below the surface, at the interface between warmer, shallow water , and colder, deeper water >>
<< Now for the first time [AA] have accurately simulated the motion of internal tides along a shelf break called the Middle Atlantic Bight ... >>
Jennifer Chu. Researchers find explanation for interacting giant, hidden ocean waves. Sept. 28, 2016.
http://phys.org/news/2016-09-explanation-interacting-giant-hidden-ocean.html
Samuel M. Kelly, Pierre F. J. Lermusiaux. Internal-tide interactions with the Gulf Stream and Middle Atlantic Bight shelfbreak front. Journal of Geophysical Research: Oceans. Volume 121, Issue 8 Aug. 2016 Pages 6271–6294 DOI:10.1002/2016JC011639
http://onlinelibrary.wiley.com/doi/10.1002/2016JC011639/abstract