Tides Worksheet (page 1)
Read the paragraphs below and then scan the table on the following page. On a separate
sheet, answer Questions 1-9 below.
People that make their living on or from the sea, such as fishermen and sailors, must pay
careful attention to the tides. Even people that simply enjoy visiting the beach or going
boating are affected by the daily tidal cycle. In many areas, there is just a foot or two
difference between successive high and low tides. However, this difference, called the
tidal range, varies over time and from place to place. The greatest tidal range in the
world occurs in Canada’s Bay of Fundy, where the difference between low and high tides
can be as much as 21 meters (nearly 70 feet)!
The greatest tidal range, the highest high tides and lowest low tides all occur when the
sun and moon are lined up. As you will see below, these so-called spring tides occur in a
regular pattern. Some animals (e.g., horseshoe crabs, sea turtles) lay eggs onshore on the
date of the highest high tide in a season. The smallest tidal range, lowest high tides and
highest low tides also occur in a regular pattern. These are called neap tides.
1. Look at the data for high and low tide levels on the table on the next page. Find
the highest (i.e., maximum) high tide and the lowest (i.e., minimum) low tide and
write down the date of each. These are spring tides.
2. Look at the table and find the date(s) of the lowest high tide and the highest low
tide and record them. These are neap tides.
3. Now calculate the tidal range for each day by finding the difference between high
tide and low tide levels for that day. Record it in the column titled “Tidal Range.”
The value for January 1 is given.
4. Look at the day-to-day change in the difference between high and low tide levels
that you recorded for Question 3. Describe any pattern that you detect.
5. Now graph the daily high and low tide levels on a...