When plastic gets to the ocean, it tends to accumulate in giant, circular currents, getting caught up in the natural waves of the ocean and other collected pollution, with nowhere to escape.
There is no example more famous than the Great Pacific Garbage Patch, a heap of trash roughly double the size of Texas that resides in the ocean between Hawaii and California.
A problem of this size requires a massive solution — so scientists turned to space to conceptualize how to clean it up.
Research scientist Rodrigo Duran from the Planetary Science Institute and Luca Kunz, a graduate student at the University of Hamburg, just authored a new paper published in the journal “Ocean Science.”
In it, Duran and Kunz used satellites to analyze the surface currents of the ocean. Then, they identified regions that, due to their circulation patterns, attract objects drifting nearby into large garbage patches.
Essentially — they watched garbage patches form from space.
Their work was heavily inspired by renowned physicist Sir Isaac Newton.
“Sir Isaac Newton was the first to solve trajectory problems while trying to understand celestial bodies orbiting within a gravity field. But, he was thinking in terms of how Earth orbits the Sun,” Duran said in a statement.
“Over the following centuries, new tools and ideas were used to solve these kinds of extremely complicated problems. However, it wasn’t until the last couple of decades that these tools were adapted to surface ocean currents and wind, which bring an additional level of complexity. It’s not like the equations of gravity, which remain predictable for a very long time. The ocean is always changing.”
The research team combined Newton’s lasting school of thought with over 20 years of ocean current satellite data collected by floating sensors, called drifters.
These drifters ride ocean currents and record their trajectories.
From this data, the scientists were able to identify and categorize 3.5 million Transient Attracting Profiles, which they call TRAPs for short.
TRAPs are regions where drifting objects, including garbage, are brought together by two or more groupings of circular currents.
Each of these circular currents — or eddies — can be anywhere from 60 to 180 miles wide and collect drifting objects into areas larger than a city. And when these collections come together, they are stable for an average of six days.
What does this mean?
“With this information, we can let the currents do the work. Instead of boats slowly trawling and burning fuel, they can hold their position and keep the nets steady at a location where currents funnel and aggregate drifting objects which will theoretically save cleanup crews time, money, and fuel,” Duran explained.
The idea is that instead of chasing down the biggest contagions of trash piling up in the ocean, teams can strategically place nets at fixed points to gather the items that need to be removed from the waters.
The currents — not engines — would collect the waste, lowering emissions and reducing costs for major efforts to curb ocean pollution.
This information is particularly vital to the work of The Ocean Cleanup, a Netherlands-based nonprofit that is developing technologies to clean the world’s oceans of plastic. The group was a collaborator on this research.
On top of supporting scientific research about ocean pollution, The Ocean Cleanup is working to streamline technology that better identifies, tracks, and cleans up ocean plastics.
Right now, The Ocean Cleanup has been measuring the flow of trash from rivers to oceans across the globe, using AI cameras attached to bridges that predict where plastic is entering the ocean.
The organization’s most well-known invention, however, is its ocean cleaning system, which sweeps the water with a mesh net to gather plastic that is brought to land and recycled. It has been utilizing ocean currents to do this ever since its inception over a decade ago.
“The circulating currents in the garbage patch move the plastic around, creating natural ever-shifting hotspots of higher concentration,” The Ocean Cleanup explains on its website. “With the help of computational modeling, we predict where these hotspots are and place the cleanup systems in these areas.”
But with improvements in this approach — as evidenced by the Planetary Science Institute’s latest research — cleanup efforts could be expedited even further, leading to a more efficient and sustainable eradication of the Great Pacific Garbage Patch.
In addition, this research could have helpful applications beyond ocean cleaning efforts.
“Our analysis contributes to a better understanding of TRAPs, which can even benefit other offshore operations besides ocean cleanups, such as optimal drifter deployment, oil spill containment, and humanitarian search and rescue,” the researchers wrote in their paper.
Duran added: “It’s a very exciting time.”
Header image courtesy of The Ocean Cleanup
