1. WATER PROPERTIES www.pwssc.org

2. Why do we want to explore the ocean? The Oceans are the number one driver of weather and climate They are also important for transportation and food To learn about the organisms that live there Almost every type of plant and animal known to science can be found in the ocean www.pwssc.org

3. What is it like underwater? Dark Deep Lots of pressure Big Cold Salty www.pwssc.org

4. Three Properties of Water Density Pressure Buoyancy www.pwssc.org

5. Density www.pwssc.org

6. Density Example A rock and a crumpled piece of paper are the same size. They have the same Volume. The rock weighs more than the piece of paper, it has greater Mass. Which item has a greater Density? www.pwssc.org

7. Density and States of Matter www.pwssc.org Density refers to how closely "packed" or "crowded" the material appears to be Solid Liquid Gas http://www.cofc.edu/~martine/111Lect Week1_files/image008.jpg

8. Pressure How much force is applied to an area. Measured in Pascals (Pa), atmospheres (ATM), or pounds per square inch (psi) There are many other units as well! Water pressure is caused by the weight of water pressing down on what is beneath it. The deeper you go, the more water is above you, the greater the pressure. www.pwssc.org

9. Water Pressure Water and air are both fluids. Water is more dense than air, so it sinks. In a bottle with half air and half water the water stays at the bottom. www.pwssc.org

10. Units of Pressure At sea level the pressure is equal to: 101,325 Pa 14.7 psi 1 ATM Our bodies are used to this level of pressure, they exert the same amount of pressure back. Underwater 10 meters (33 feet) of water above you will exert 1 ATM of pressure www.pwssc.org

11. Water Pressure This Styrofoam cup was sent to 1279 m and felt 1833 psi or 125 atmospheres of pressure Why caused the cup to get smaller? Has the density of the cup changed? www.pwssc.org http://iodp.tamu.e du/scienceops/gall ery/exp311/week7/ pages/exp311_107. html

12. High Pressure Adaptations Animals that live in the deep have adapted to a high pressure environment. No excess cavities Soft, pliable bones www.pwssc.org http://ocean.nationalgeographic.com/ocean/ photos/deep-sea-creatures/

13. Buoyancy The ability of something to float in a fluid (water, air, etc.) Archimedes Principle: An object is buoyed up by a force equal to the weight of the fluid displaced by the object. www.pwssc.org http://en.wikipedia.org/wiki/Image:Buoyancy.svg

14. States of Buoyancy Positive Buoyancy (float) The weight of the object is less than the weight of the displaced water. Negative Buoyancy (sink) The weight of the object is MORE than the weight of the displaced water. Neutral Buoyancy (hover) The weight of the object is the SAME as the weight of the water displaced. www.pwssc.org