Floating Stuff and Currents

Currents can be identified by their temperature, salinity, and density. Students identified which currents were warm and cold by looking at where they are coming from and then colored them appropriately.

Sailors have known about some of these currents for a very long time. Early explorers knew it took less time to go to Europe from North America and not the other way, even if they didn't know it was the slightly warmer, slightly faster Gulf Stream that was carrying them along. Scientists who study currents have historically dropped stuff into the ocean and recorded where it has turned up. Yes, those messages in a bottle can be useful.

Curtis Ebbesmeyer is one of the leading oceanographers in current research and he doesn't drop any bottles. Instead he tracks cargo that is lost overboard from large container ships in trans-oceanic crossings. He started with a cargo of Nike sneakers, but has also worked with plastic ducks (pictured), legos. pumice from volcanic eruptions, and wooden barrels. Mr. Ebbesmeyer is most famous for his research on the plastic ducks. Although many ducks, beavers, turtles, and frogs have been recovered, oceanic currents are carrying them further still...

Students practiced latitude and longitude by plotting some points of a cargo lost overboard and where some of the shipment washed up beaches, then they read articles and answered questions, and finished up by listening to a podcast interviewing Curtis Ebbesmeyer, the oceanographer who studies sneakers, rubber ducks, and other floating debris. You can listen to the podcast here.

In the interview, and in the readings, gyres full of floating plastic debris are discussed. Here is a map showing some of the locations of these gyres. Click on the picture to get a larger view. Here is an excellent website with more information and some nifty graphics. We will continue to discuss this in class.