14 DAY TRIAL // An international team of researchers featuring experts from the United States and France recently teamed up to study an interesting phenomenon that sometime occurs under the surface of oceans, called underwater waves, or internal waves. These formations can be very dangerous for a variety of reasons.
The origins of these weird waves has been under study for a relatively long time, but did not produce significant results to date. In the new study, scientists were able to figure out how these waves emerge, and also how they are able to reach heights of several hundred feet.
In addition to being harmful to ocean ecosystems – where they can displace coral reefs and kill off numerous sea creatures during a single pass – underwater waves also play an important role in influencing Earth's climate. In order to understand these effects, researchers conducted studies both in the lab, and in the South China Sea.
This particular sea is home to the largest underwater waves on Earth, the team says, so naturally this location was their first choice when deciding to conduct this investigation. Experts were able to determine that both normal and internal waves look pretty much the same.
However, differences do pop up when analyzing the density, temperature or salinity of the water in both instances. These variations occur due to a process called stratification, where water with different properties forms layers in the ocean, occupying different depths.
The new investigation was led by scientists at the Massachusetts Institute of Technology (MIT) and the Woods Hole Oceanographic Institution (WHOI), in the US, and the Ecole Centrale de Lyon, the Ecole Normale Superieure de Lyon, and the University of Grenoble Alpes, in France. The work was coordinated by the US Office of Naval Research (ONR).
In a paper published in the latest issue of the esteemed journal Geophysical Research Letters, scientists argue that internal waves can reach heights of up to 170 meters (550 feet) and speeds of up to several centimeters per second due to the influences of mountain ridges on the sea floor.
These terrain features generate waves under the ocean surface that propagate at very low speeds and reach massive heights. Previously, it was though that only some landscape features, such as the peaks of submerged ranges, produced these waves, but the new study shows that entire ridges play a role.
This discovery is more important to scientists now than it was a decade ago, since they have come to realize that submerged waves play a very important role in mixing ocean water, and drawing heat from the atmosphere. This implies that they are critical to the ocean's ability to control global warming.
“It’s an important missing piece of the puzzle in climate modeling. Right now, global climate models are not able to capture these processes. You get a different answer […] if you don’t account for these waves,” says MIT associate professor of mechanical engineering Thomas Peacock, the leader of the study.