Events Calendar

Astani CEE Department Seminar

Speaker: Jose C. Borrero, Ph.D., ASR Marine Consulting and Research, Raglan, New Zealand; Adjunct Assistant Professor, USC -Sonny Astani Department of Civil and Environmental Engineering

Talk Title: Modelling ‘Pollution Pathways’ From Seashore Litter to Oceanic Garbage Gyres:

Abstract:
Transforming Scientific Investigations into Tools for Education and Raising Awareness

This presentation will discuss a recent project designed to convert technical output from scientific investigations into education and outreach materials aimed at raising public awareness of the environmental hazards associated with oceanic plastic pollution and floating debris.

The project began with our participation on a research cruise across the South Atlantic Ocean, one of several recent and ongoing research voyages aimed at documenting and quantifying the distribution and concentration of plastic pollution within the five subtropical convergence zones (also known as gyres or ‘garbage patches’) of the World Ocean. Samples of floating debris were collected along the route from Rio de Janeiro to Ascension Island using both standard and high-speed tow trawls along the ship’s path.

Following the voyage, we began an investigation into existing literature describing marine debris, plastic pollution and the formation of the oceanic garbage gyres. Noting a gap in existing models, we focused on developing a model linking realistic representations of debris released in to the oceanic environment and the formation of the accumulation zones. To accomplish this, a global oceanic circulation model was coupled to a Lagrangian particle-tracking model to simulate the input, transport and accumulation of floating debris. The volume of material introduced into the model is based on factors such as coastal population density and watershed area and is assumed to increase with time.

Using hindcast data sets of global oceanic currents to drive the circulation, the modeling results clearly show the formation of five accumulation zones in the subtropical latitudes of the major ocean basins. The relative size and concentration of each clearly illustrate the dominance of the accumulation zones in the northern hemisphere, while smaller seas surrounded by densely populated areas are also shown to have a high concentration of floating debris. We also determine the relative contribution of different source regions to the total amount of material in a particular accumulation zone.

This study provides a framework for describing the transport, distribution and accumulation of floating marine debris which can be scaled to focus on regional effects and can be continuously updated and adapted to assess scenarios reflecting changes in the production and disposal of debris worldwide. The output from our study is currently being used to develop unique interactive tools and web-based ‘experiences’ designed to raise public awareness of this issue.




Biography: Dr. Borrero has earned his Ph.D. in civil (coastal)engineering from the University of Southern California in 2002. Since 2006 he has worked with ASR Ltd., a consulting firm based in Raglan New Zealand, specializing in hydrodynamic modelling of aquatic systems, the design and implementation of innovative shore protection schemes and the design and construction of artificial surfing reefs.

Host: Dr. Patrick Lynett

Location: Kaprielian Hall (KAP) - 209 Conference Room

Audiences: Everyone Is Invited

Contact: Evangeline Reyes