In a first, scientists plan to submerge pendulums in the ocean to reduce coastal erosion

Underwater pendulum to absorb waves

The project involves installing a grid of pendulums tethered to the seafloor. When ocean waves pass over the pendulums, each resonator begins to oscillate, thereby absorbing wave energy and dampening turbulence. The pendulums are made of less dense material than water. 

The researchers highlight that this system could easily absorb ocean waves, and reduce the risk of coastal erosion in the near future. This solution has been designed to protect coastal sites with high ecological value as well as those that attract tourists. Furthermore, the device is said to be low-cost and has little impact on the environment or water circulation. “With respect to rubble mound breakwaters, this type of structures has a small impact on water circulation,” notes the paper. 

As per Popular Science, the project is still in its early stages of laboratory design, but preliminary results have been promising. In the lab, they assembled 11 pendulums made of half-meter-long plastic cylinders that were submerged in a 50-meter-long tank. 

The results showed that the device could reduce wave amplitudes by up to 80 per cent.

“The purpose of METAREEF is to investigate to which extent the concept of metamaterial wave control can be applied to an efficient attenuation system for surface gravity waves,” said the paper.

The preliminary results are promising, and the team is confident that the device can be customized for larger applications. They will continue to experiment in order to create a more sophisticated tool that can be used to protect threatened coastlines as well as valuable structures such as offshore platforms. It could be a game changer in terms of protecting coastal towns from beach erosion.

According to the report, the team will present their findings at the annual International Workshop on Water Waves and Floating Bodies in Giardini Naxos, Italy.