One World Ocean
Students learn about ocean currents and the difference between salt and fresh water. Using colored ice cubes, they see how cold and warm water mix and how this mixing causes currents. Students also learn how surface currents occur due to wind streams, how fresh water floats on top of salt water, the difference between water in the ocean and fresh water throughout the planet, and how engineers are involved in the design of ocean water systems for human use.
Figure 1. Major ocean currentsCopyright National Aeronautics and Space Administration, http://www.nasa.gov/
As resources on land become more scarce, engineers are looking to the ocean to meet human needs for food, minerals and transportation. Engineers develop systems for operation on and in the ocean. A huge area of interest for ocean engineering is hydrodynamics and acoustics—to communicate underwater using sound. To design with sound, engineers must understand the fluid dynamics of the ocean and sound waves. Engineers also work on many other projects involving the ocean, including the design of seaports, ships and submarines. They work with geologists to design better equipment for drilling oil deep on the ocean floor, and with marine biologists to monitor natural ecosystems within the ocean. Other engineers design equipment that can measure the temperature and depth of the ocean from space.
After this activity, students should be able to:
- Compare and contrast the properties of salt water in the oceans/seas and freshwater elsewhere on the planet.
- Describe mixing caused by currents in the ocean, including the effects of warm and cold water as well as surface currents.
- List several systems that engineers are designing that involve the ocean as a resource.