Today students began class with a BrainPop on currents and took the quiz. Tim and Moby did an excellent job describing how currents affect global weather patterns. They also explained global water circulation in the global conveyor belt.Click on the photo for a better view.
Students took notes on dissolved oxygen and learned that there is less oxygen available in the water than in the air we breath (12 parts per million vs 200 pmm) and that dissolved oxygen varies with temperature. Cold water holds more DO, just like cold sodas have more carbonation.
Pressure is the weight of particles above you and increases with depth in water. Right now there is one atmosphere of pressure squeezing on all of us, but we are used to it, so we don't notice the difference. We may notice our ears popping when driving over Shenandoah or flying in an airplane when pressure decreases. Water is 800 times more dense than air, so underwater, pressure increases dramatically. Pressure increases one atmosphere with every ten feet of depth, so all you need to do is dive down the deep end of the pool and you will feel an increase in pressure to two atmospheres (one for the water, and one for the air)
Scientists think it is funny to take styrofoam deep into the ocean because the pressure underwater will squeeze the air out of the styrofoam and "shrink it." Really it is just compressed and more dense. Here is a photo of what happens to styrofoam wig-heads and cups when taken down a few thousand feet, a change of several atmospheres of pressure.
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| Brittany oversees the boys as Brendan, Brandon, and Bruce try to measure the water correctly |
Students finished class with a lab demonstration of how pressure increases with depth using cups of water with three holes. Water squirted further out of the bottom hole because there was more weight and pressure pushing down on that part of the cup. Students did an excellent job working together and cleaning up.
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| Morgan removes the tape, Micheal holds the ruler, and all try to read the measurements |
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| Carlton peels the tape while Corrinn, Courtney, and Cherie get their measurements |
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| In this photo are Noel, Nate, Rachel, and Tommy |
Scientists think it is funny to take styrofoam deep into the ocean because the pressure underwater will squeeze the air out of the styrofoam and "shrink it." Really it is just compressed and more dense. Here is a photo of what happens to styrofoam wig-heads and cups when taken down a few thousand feet, a change of several atmospheres of pressure. 
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