The information provided here is for teachers.  It provides a set of inquiry-based and discovery-based activities in which students can use tide data to discover patterns and make guesses about their origins.  I believe this kind of activity can be an integral part of the curriculum.   

Students interested in tides, and especially the periodic patterns, can take this very far; it would make a great science fair project to gather more data and use the data to make hypotheses about the forces driving tides in various parts of the ocean basins.  [For more background, the teacher should go HERE.]  The suggested inquiries given here become progressively more difficult as you move down the page.  Exercises dealing with the 1-day and 10-day graphs are deemed suitable for all or most students; those involving the 30- and 60-day graphs are more challenging.

Tide heights at thousands of locations around the world are collected hour by hour. Using the Internet, anyone can obtain all of this data easily. One place to get data is the site of the National Oceanographic and Atmospheric Administration (NOAA, pronounced Noah"), part of the US Commerce Department. Go to http://www.co-ops.nos.noaa.gov/data_res.html and select any link under "Verified / Historical Water Level Data." For example, choosing U.S. and Global Coastal Stations lets you select from hundreds of coastal stations around the world. You can select what time period you want and choose from many formats.  You can choose whether to display all data or just highs and lows, for example.  If you are skillful in using spreadsheets, you can download and graph the data in many different ways.

On the next two pages we present graphs of tide data from the station at Hilo Bay, Hawaii, for February and March, 2000. We have shown the data for different time periods, so students can identify patterns in the data over different time scales. Students can use the process of inquiry to find various patterns in these data and relate these patterns to their knowledge of the factors that cause tides.  [Tide heights are given from an arbitrary point, so some heights are negative.  If you think this may bother your students, you can add a constant to the numbers to make the lowest measurement = zero.]

Below are some suggested questions for each graph to help guide students in their inquiry.  Teachers: GO HERE for a Guide to possible responses and discussion of these questions.  (Times given in the graphs are local times)

1-day graph (Graph 1) 

10-day graph  (Graph 2)

30-day graph  (Graph 3)

60-day graph (Graph 4)

Additional Activities