The Great Pacific Garbage Patch is the largest landfill in the world, though "landfill" isn't exactly the most fitting word for the thing that has formed in the middle of the Pacific ocean. The garbage patch, also known as the Pacific Trash Vortex or Eastern Garbage Patch, consists of 3.5 million tons of trash -- 90% of which is plastic debris -- that is swirling around between Hawaii and California.

The garbage vortex, which consists of waste such as toilet seats, camera cases and oil drums, accumulates from all over the world. As it moves further into the ocean, it becomes trapped by the strong flow of the North Pacific Gyre, the center of a large-scale system of rotating ocean currents.

The Great Pacific Garbage Patch is twice the size of Texas, while some scientists have argued that its mass has extended to twice the size of the United States. Though large pieces of waste remain intact in the patch, a majority of it is comprised of tiny bits of plastic, barely visible to the human eye. Due to the small size of the plastic and its location beneath the ocean's surface, the garbage patch does not show up in satellite images.

Scientists had suspected the existence of the plastic patch since 1988, but it wasn't confirmed until Charles J. Moore, a California-based sea researcher, stumbled upon the area in 1997 on his way home from a sailing race. Moore, who once described the area as plastic soup, released a study in 1999 indicating that the area contained six times more plastic than plankton. Recently, some samples have shown 48 parts plastic for every 1 plankton, meaning the levels of plastic concentration could have increased fivefold in just over a decade.

More than 200 billion pounds of plastic are created every year and at least 10% of it ends up in the ocean. Land-based plastic comprises 80% of the garbage patch; this plastic litter slowly makes it way from land, floating on the ocean's surface for years before reaching its final destination. From the west coast of North America, it takes roughly five years for plastic debris to travel in the ocean before getting caught in the gyre, and about one year from the east coast of Asia.

As it travels, the non-biodegradable plastic continues to disintegrate into tinier and tinier pieces, even down to the molecular level. The smaller the plastic breaks down, the higher chance it has of being ingested by aquatic organisms. Much of the larger plastic is covered in barnacles, making the area a popular destination for scientists studying the impact of plastic on the ecosystem.