Garbage in Gyres

You might be thinking, how does all that garbage stay in the same place, especially in the North Pacific Gyre. Shouldn't the garbage diffuse into the rest of the ocean so that there is just a little bit of garbage everywhere, but not so much that it's unmanageable? The answer is no, because of the characteristics of a gyre. Gyres rotate and become almost like a whirlpool; once you're in, it's hard to get out. A good way to picture it is to imagine the garbage as foam piled up in the middle of a hot tub where it is the calmest. The garbage can't even fight its way out like a human can.

Our main contact, Curtis Ebbesmeyer, has told us: "The garbage patch is localed under the subtropical high pressure cell. Dynamics of the winds and currents beneath the cell cause flotsam to converge into the patch." This high is called the North Pacific subtropical high and it pushes storms north or south. This high is the eye of the North Pacific Gyre and it consists of weak winds and slow currents just naturally collect marine debris, flotsam. In actuality, because similar wind and current configurations occur in all major oceans, so every large body of water has this problem of having a trash vortex. Not a lot of people know about this problem because that area of the Pacific Ocean is not frequently travelled. 70% of marine litter sinks and the ligher plastic photodegrades into smaller components which cannot be seen unless you're on a boat right on top of all the garbage, which is highly unlikely for an ordinary citizen.

Anyways, garbage accumulates in the ocean in these gyres and us silly humans continue dumping trash into the ocean off boats and land. As you might have read in previous blogs by my other group members, it takes 450 years for a plastic bottle to fully photodegrade but they never ever biodegrade. Plastic bottles aren't even the worst thing that people throw into the ocean. Disposable diapers apparently take 500 years to become invisible to the human eye but the effect on the environment can be seen much longer than that.

In certain areas, ocean currents carry the garbage, concentrate it in one area, and prevent it from washing ashore, especially in the circulating currents in stable weather conditions. In the image above, it can be seen that it is in between the two gyres where there is both warm and cold water that most garbage is collected. In each of the smaller gyres, the garbage moves toward the other gyre. But storms and rain can wash out some of the garbage out of the edges of the gyre and onto the beaches and shorelines of nearby Hawaiian islands that are in the same general area. This is often referred to as "a big animal without a leash. When it gets close to an island, the garbage patch barfs, and you get a beach covered with this confetti of plastic," said Ebbesmeyer.

http://viewfromthemountain.typepad.com/david_sobotta_weblog/2006/08/the_eastern_gar.html
http://www.howstuffworks.com
http://oceans.greenpeace.org/en/the-expedition/news/trashing-our-oceans
www.mindfully.org/Plastic/Ocean/Trashing-Oceans-Plastic4nov02.htm