Wednesday, August 20, 2014

Waves, Tides, and Tsunamis

Students started class by going over safety rules and procedures with a pictorial challenge. Afterwards students took the safety test. Today in class we discussed waves, powered by wind, and their parts. 

We also discussed tsunamis, which fascinate most students. Tsunamis are caused by underwater earthquakes and they displace water. Displacement of water causes a large wave or energy to travel through the water, but it cannot be seen at the surface until the wave approaches shallow water. (Confused? Check out the diagram to the left) Because the wave is not felt in deep water, going out to sea is one option for escaping a tsunami, getting onto land with higher elevation is another option. There are places in Japan and Hawaii where fishermen went out to sea in the morning and when they returned, their villages had been washed away.

Next we discussed tides. Tides are caused by the moon's gravitational pull on the ocean. The sun has an impact too, but the moon's impact is greater because it is a lot closer. The ocean water bulges towards the moon and causes the high tide... areas perpendicular to the bulge are having a low tide. Because the earth is rotating, each place is going to have two high tides and two low tides each day.Spring high tides are exceptionally high and really really low when the earth, sun, and moon are all lined up in a row. 

We finished class by discussing temperature and locations on the globe and watched some Blue Planet on tides, tidal bores, sand bubbler crabs that comb through sand eating macro-organisms, and bears that eat clams.

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Computer Lab Etiquette

You are in the computer lab to do work for this class. If you are not doing work, then we will have problems.

Do not pack up early. Work until the bell or until MsJ says.

SAVE OFTEN. And if you save to a key, also save it to your number. If you lose it, you will have to do it again.

If MsJ asks for your attention, stop what you are doing and listen to what she has to say.

You may watch videos about your organism through reliable websites.

You may listen to music through the computer if you have your own headphones. Rule1 MsJ cannot hear it. You get one warning. Rule2 Turn it on and listen – no million clicks and constant changing. Take both ear phones out when MsJ is talking.