Picture a massive wave moving in toward a beach, eventually pitching and breaking as it’s pushed closer and closer to shore. It all sounds pretty basic because we see those waves on the surface of the ocean everyday. But have you ever imagined the effects of that same phenomenon happening underwater? Well that’s exactly what Harper Simmons, an associate professor of oceanography at the University of Alaska Fairbanks, has been studying since 2007 according to Alaska Public Media.
Specifically, Harper and other researchers from more than two dozen institutions have been studying the movement of massive underwater waves, called internal waves, in the South China Sea. “They move at approximately three meters per second, whereas a surface wave might move at 10 or 20 times that rate,” Simmons said. “So they’re massive waves; they contain huge amounts of energy, but they evolve in slow motion relative to what we would see at the surface.” These internal waves require stratification, with water layering based on things like salinity and temperature. Along with those variables, tide changes will all come together to create underwater waves moving throughout the ocean. In the video illustration here we see density layers moving with the regular back-and-forth tidal flow, creating the large internal waves (shown in red underwater, and in white when seen from above).
Understanding and observing this complexity within the ocean is allowing Simmons to follow how nutrients are moved underwater and how they impact its many ecosystems. So while we as surfers see ocean waves as the physical manifestation of energy in nature’s most dynamic state on the surface, underwater, the same phenomenon is truly giving life to everything that swims below.
