Activity:  Examine local tide measurements for location, elevation change, and variation from predicted values.

Pre-Activity:  Homework to find local tide stations and local elevation changes.

Do Now:  What is the time difference between low and high tide?  ((What is the weight of that water change over a one mile area?))

Aim:  Understanding global, regional, and local tide patterns, as well as reasons for variations.

Major Assignment:  Examine global and local tides, and compare predicted to observed.  Discuss impact of tides on local areas.

Processes, Skills, Goals:  Researching local environmental variables, making predictions, explaining potential causes of variations, as well as methods of proving the hypothesis.  Examining tidal oscillation in graph form.

Content:  Tides as a significant factor in life on earth, including humans and seals.

Instructions:  Ask students to explain what they already know about tides.  Double-check that they know that it is caused by lunar and solar positions, and the movement of the earth.  Show maps and videos of tidal movement to help anchor the concept.  Remind them that although the maps are flat, the earth is round, and the tidal movements are created by fluid flow over a curved surface, hence complex mathematics and chaos theory.  Yet we still can boat in the waters with confidence.  Ask for personal stories of tides, and be ready to tell one (e.g. catching fish, getting stranded, or from videos).  Extend the discussion to include the seal's perspective.

Materials:  Tides tables, lunar tables, tidal videos from NASA, tidal plots from NOAA, model of earth, sun and moon for tides

Guiding Questions:  Has anyone been on the beach with their blanket near the shore when the tide was out, and then stayed a long time.  What happened?  Any other stories about tides?  What did you find from your homework question on local tides?  How is tide measured?  What about every other place the water is?  Why is a few local location good enough?  What causes tides?  What effects do they have on humans?  Seals?  Other animals and plants?  

Homework:  Find videos or photos of interesting tide changes, their location, and associated elevation change data.