So, When is High Tide?

Image from: https://www.visitmyrtlebeach.com/things-to-do/beaches/tides-and-conditions/

​Ask students to study the chart and write down 3 things they notice and 3 questions they have about this schedule.   

Questions to discuss with students:
1.  What patterns do you notice in this chart?  

2.  Approximately how much time passes between high and low tide?  

3.  Approximately how much time passes between high tides?

4.  Look at 9/3/2021.  Why is there only one low tide on that day?


5.  Why do you think we publish this tide schedule?  
     Who would care to know what time the tides occur?

​6.  On Sept. 17, a low tide seems to be missing - what's happening here?

7.  2.  What is the tide like now?  Click here, then scroll to this month's tide chart.


A few things to note:

• Tides are based on a lunar day, so 24 hours 50 mIn, not the 24 hour solar day that we usually consider.  (This has to do with the moon’s revolution and the time it takes Earth to catch up to it.)  Read about tides. 
• Because the Earth and Moon are in constant motion,   Earth’s ocean levels are constantly changing.  The moment after maximum high tide, the water levels begin receding towards low tide, and vice versa.
• There are usually 4 tides each 24hr day (two high and two low).  BUT...some days there are only 3 if the 4th one occurs after midnight.  High tides occur every 12 hours and 25 mins.  The time between high and low tides is 6 hours and 12.5min.  

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