Human Impact on the Pacific Garbage Patch
The Great Pacific Garbage Patch is a collection of marine debris in the North Pacific Ocean. Also known as, the Pacific trash vortex, the garbage patch is actually two distinct collections of debris bounded by the massive North Pacific Subtropical Gyre. The first one near Japan is known as the Western Garbage Patch. The second one lies between California and Hawaii and is known as the Eastern Garbage Patch.
The Western and Eastern Garbage Patches are connected together by the Subtropical Convergence Zone of the North Pacific. The Convergence Zone is actually a place where Arctic water meets war South Pacific water. This convergence creates a water highway, which is used by the Western Patch and Eastern Patch Garbage debris to travel from one patch to the other.
The Pacific Trash Vortex is surrounded by what is known as North Pacific Subtropical Gyre. Gyre in an ocean actually refers to a current system that moves in a circular pattern.
This whole circular current system is formed by Earth’s rotation and wind patterns. To be specific, the North Pacific Subtropical Gyre is actually formed by four currents, which are:
- North Pacific Current
- Kuroshiro Current
- North Equatorial Current
- California Current
The aforementioned four currents form a circular system of currents because all four currents move in a clockwise direction. The total area covered by this current system is 7.7 million miles squared or 20 million kilometres squared. The Great Pacific Garbage Patch lies within that massive area. Interestingly, the central area is very calm and is a place where the oceanic debris is stuck. Any garbage that is outside the circular current system slowly sucks in the debris and pushes it right in the calm central area.
The exact size of the Pacific Trash Vortex is not known. Since there is no floating island of plastic out there, it is not possible to get a size estimate using drones or even satellite imagery. The estimate actually varies, some estimate the size of the patch to be as small as 700,000 square kilometres, while some say that the patch is as big as 15,000,000 square kilometres.
The Garbage Patch mostly consists of plastic that remains suspended in the water column beneath the water surface. Since plastic is inorganic and non-biodegradable, the only thing that happens is photo degradation. The plastic disintegrates in smaller and smaller pieces over time and stays suspended in this process.
‘A passive system is currently in development, which uses the ocean currents as its driving force to catch and concentrate the plastic. By suspending a large sea anchor in a deep, slow moving wa...
