A new study out of the University of Miami shows how ocean currents transport floating marine debris, and explains how garbage patches form in the oceans. Researchers have developed a mathematical model that simulates what small spherical objects would do on the surface of the ocean.
The model was fed information on wind and currents to simulate the movement of marine debris. The data was then compared to the information from satellite tracked surface bouys. Data from anchored bouys and unanchored bouys were used to see how each accumulated in the five ocean gyres over a 20 yr period.
The unanchored drifting bouys over time were found at the center of the gyres , where the plastics are mostly found. The anchored drifters that are designed to mimic the motion of the water take a longer amount of time to reach the center areas.
The study takes into account the effects of wind and water induced drag on the objects, found the accumulation of the debris in the subtropical gyres happens to fast to be attributed to the trade winds that meet in these regions. The size and weight of the drifting object must be taken in to consideration to fully explain the accumulation.
Practical application of the mathematical model include tracking ship wrecks, airplane debris, sea ice , and pollution.