Almost 8 billion kilograms of plastic is dumped into oceans every year. NASA has released an animation showing this dumping over the course of 18 months. The animation tracks the journey of plastics on a global level.
The plastic that is dumped in the ocean does not float on the surface only. It also accumulates abundantly in the North Atlantic and North Pacific garbage gyres called the garbage patches. Plastic here can be measured through the manual net technique, but the result is not accurate.
NASA’s work is brought forward by the researchers at the University of Michigan. The technique uses measurements of how rough the ocean surface is taken with eight microsatellites, which allows scientists to calculate wind speeds in the ocean. Water acts calmer when plastic is present near the surface.
“In cleaner waters, there’s a high degree of agreement between ocean roughness and wind speed,” Chris Ruf, one of the authors of the research, told NASA Earth Observatory. “But as you head into the Great Pacific Garbage Patch, you see a bigger discrepancy between wind speed measurements and the roughness of the surface.”
Researchers at the University of Michigan cross-referenced the space radar measurements of surface roughness with wind speed measurements from other sources on the ground (or seas, as the case may be) to spot places in the ocean where waters were calmer, but wind speeds might still have been strong. They then compared those with other models of ocean plastics, looking at locations between 38 degrees north and south of the equator.
The data was collected from April 2017 till September 2018. This project is the first of its kind. The team also found out some trends like garbage concentrations in the Great Pacific Garbage Patch were higher in the summer and lower in the winter. This was attributed to vertical mixing enabled by the cold weather.
This tool can aid in devising ways to clean up the ocean and to prevent the trash from ending up in the water. Experts believe that there is so much trash in the ocean that it will be impossible to completely clean it. Now, the focus must be shifted to reduction and elimination of plastics.
