Featured Research

from universities, journals, and other organizations

Who is to blame for ocean trash? Giant garbage patches help redefine ocean boundaries

Date:
September 2, 2014
Source:
American Institute of Physics (AIP)
Summary:
Researchers have created a new model that could help determine what area of the world is to blame for each ocean garbage patch of floating debris – a difficult task for a system as complex and massive as the ocean.

This map shows how researchers from UNSW divided the entire ocean into seven regions whose waters mix very little. The map could yield insights into the formation of giant ocean garbage patches, as well as ocean ecology.
Credit: Gary Froyland, Robyn M. Stuart, and Erik van Sebille/UNSW

The Great Pacific Garbage Patch is an area of environmental concern between Hawaii and California where the ocean surface is marred by scattered pieces of plastic, which outweigh plankton in that part of the ocean and pose risks to fish, turtles and birds that eat the trash. Scientists believe the garbage patch is but one of at least five, each located in the center of large, circular ocean currents called gyres that suck in and trap floating debris.

Researchers from the University of New South Wales (UNSW), in Sydney, Australia, have created a new model that could help determine who's to blame for each garbage patch -- a difficult task for a system as complex and massive as the ocean. The researchers describe the model in a paper published in the journal Chaos, from AIP Publishing.

"In some cases, you can have a country far away from a garbage patch that's unexpectedly contributing directly to the patch," said Gary Froyland, a mathematician at UNSW. For example, the ocean debris from Madagascar and Mozambique would most likely flow into the south Atlantic, even though the two countries' coastlines border the Indian Ocean.

The new model could also help determine how quickly garbage leaks from one patch into another, said Erik van Sebille, an oceanographer who collaborated with Froyland on the Chaos paper. "We can use the new model to explore, for example, how quickly trash from Australia ends up in the north Pacific."

At the heart of the researchers' work on the origins and fate of floating rubbish lies a bigger question -- how well do the ocean's surface waters mix?

The Anatomy of Ocean Currents

Fast-moving ocean currents form due to winds, differences in water temperatures, salinity gradients across the globe, and the forces caused by the spinning Earth. Currents stir ocean waters, but they also serve as barriers that minimize mixing between different ocean regions, much like the blast of fast-moving air at the entrance of an air-conditioned store keeps the cold inside air from mixing with the warm outside air.

Froyland, van Sebille and their UNSW colleague, Robyn Stuart, divided the entire ocean into seven regions whose waters mix very little. Their approach borrowed mathematical methods from a field known as ergodic theory, which has been used to partition interconnected systems like the internet, computer chips and human society, and the new analysis revealed the underlying structure of the ocean without getting bogged down in complex simulations.

"Instead of using a supercomputer to move zillions of water particles around on the ocean surface, we have built a compact network model that captures the essentials of how the different parts of the ocean are connected," said Froyland.

According to the new model, parts of the Pacific and Indian oceans are actually most closely coupled to the south Atlantic, while another sliver of the Indian Ocean really belongs in the south Pacific.

"The take-home message from our work is that we have redefined the borders of the ocean basins according to how the water moves," said van Sebille. The geography of the new basins could yield insights into ocean ecology in addition to helping track ocean debris. The researchers say their modeling technique could also be applied on a smaller scale -- determining for example how much Canadian and American waters mix in the Great Lakes or how an oil spill might spread in the Gulf of Mexico.


Story Source:

The above story is based on materials provided by American Institute of Physics (AIP). Note: Materials may be edited for content and length.


Journal Reference:

  1. Gary Froyland, Robyn M. Stuart, and Erik van Sebille. How well-connected is the surface of the global ocean? Chaos: An Interdisciplinary Journal of Nonlinear Science, September 2, 2014 DOI: 10.1063/1.4892530

Cite This Page:

American Institute of Physics (AIP). "Who is to blame for ocean trash? Giant garbage patches help redefine ocean boundaries." ScienceDaily. ScienceDaily, 2 September 2014. <www.sciencedaily.com/releases/2014/09/140902114039.htm>.
American Institute of Physics (AIP). (2014, September 2). Who is to blame for ocean trash? Giant garbage patches help redefine ocean boundaries. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2014/09/140902114039.htm
American Institute of Physics (AIP). "Who is to blame for ocean trash? Giant garbage patches help redefine ocean boundaries." ScienceDaily. www.sciencedaily.com/releases/2014/09/140902114039.htm (accessed September 21, 2014).

Share This



More Earth & Climate News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Rally Held in India Ahead of UN Summit

Climate Change Rally Held in India Ahead of UN Summit

AFP (Sep. 20, 2014) Some 125 world leaders are expected to commit to action on climate change at a UN summit Tuesday called to inject momentum in struggling efforts to tackle global warming. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com
Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins