How does the ocean temperature affect a ship’s movement

Earlier this week I showed you how sailors navigated, and how they measured speed.  But, how does the ocean temperature affect a ship’s movement? This is a topic not truly explored during the Age of Exploration, but it affected how their ships moved and what routes were effective.  Besides, any homeschool science lesson that involves water and getting messy is a sure-fire hit.

Why do we care about ocean currents in an age of airplanes?

For one, most of our trade still happens through shipping.  Why spend the money to get a product up in the air, transport it across the sky, and then bring it back down?  Instead, if there is not a time crunch, which is true of most products, it is shipped across the ocean in a cargo ship.  Sea captains today are very aware of how ocean temperature affects a ship’s movement.

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Setting up the experiment to find out how the ocean temperature affects a ship’s movement

Thanks to some amazing information over at All Things Beautiful, we did two of her ocean current experiments (you’ll hear about the other tomorrow), but she’s got a lot more detail than I have.  Today, we’re going to talk about what we learned as we look at ocean temperature affecting water movement.

Supplies needed for the ocean temperature experiment

2 empty 2 liter bottles (preferably clear, so that rules out Sprite, much to Superman’s dismay); tornado tube*; blue food coloring* (I like this particular type because I can use it in icing for cake and it doesn’t thin the icing), hot water and cold water

1. Fill the cold water bottle to the very top (I got a bunch of cold water from my refrigerator, but if your refrigerator does not do that, then you can mix ice and water, or put some in the frig for a while, you want it really cold), and add several drops of blue food coloring.  Screw the top of your 2 liter bottle on and shake it like crazy. This is my lazy man way of mixing it.  Also the kids love doing it.
2. Fill your hot water bottle to the very top as well.  I just moved my tap water to as hot as it was able to get.  If you really want to go crazy you could boil water, but that seems like a good way to get a burn on yourself.  Besides my sink water was plenty hot enough.  Screw the tornado tube onto your hot water bottle.
3. Now comes the tricky part.  Working very fast put the cold water tube onto the hot water tube and twist it together.  Phyllis has some great tips on her site for doing this, I made a bit of a mess, so my tips would be useless (also why there’s no pictures of this process).  I would highly recommend having a towel under your whole area.
4. Now lay your bottles on their side and you’re ready to begin the experiment.

On to our ocean temperature experiment

This is a bit of a fire and forget activity, as long as you have a timer.  Once you’ve laid down the bottles, write down what you notice, how things are moving, and then leave it.

For five minutes, that’s right just walk away, maybe work on your math lessons for the day, or something else.

Now come back and see how the water has moved.  It’s interesting to see how the water changes over time.  But it’s not going to be a quick experiment.  We repeated this process several different times and learned quite a lot about how water moves.

As we watched the kids recorded their observations in their captain’s logbook.  Much like captains might have during the Age of Exploration.  Tomorrow, see how ocean currents are affected by large bodies of land.

What did we do with our observations about water movement?

Remember our Columbus presentation?  This is part of our observations the kids used for their presentations.  Towards the end of the month, you’ll also get to see our lesson on charting and making maps, which was an interesting experiment for us.