Visiting a beach next to an ocean is certainly fun. Your family can swim, surf, sunbath, fish or nap. But it can be a more meaningful visit if you encourage your children to learn something scientific. And science is all around you at the beach.
In this article are several statements about animals and forces of nature (ex. sand dunes and tides) that you can see or feel at the beach. Each statement is followed by questions. Read each statement to your child, then ask each question. We have provided answers to the questions, to stimulate discussion with your child.
Topic #1: If we stay here for several hours, you will notice that the waves have begun to either break higher on the beach (we may have to move our blanket further away) or break lower on the beach (the ocean will move further away from us). Even if we don’t stay long enough for you to notice this, it will happen. This is caused by the changing tide.
1. What causes tides?
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun, and the rotation of the Earth.
2. Why do the times when tides begin and end change every day?
The normal day for us is 24 hours. It is called a solar day, and it is the time that it takes for a specific site on the Earth to rotate from an exact point under the sun to the same point under the sun. If tides followed our solar day, high and low tide would occur at the same time every day. But tides follow a lunar day that is 24 hours and 50 minutes long. A lunar day is the time it takes for a specific site on the Earth to rotate from an exact point under the moon to the same point under the moon. So that extra 50 minutes means the times of high and low tides will change each day.
3. How many high tides and how many low tides occur in a day?
In the 24 hour and 50 minute lunar day, two high and two low tides will occur.
4. It always takes the same amount of time between high tide and low tide – this never changes. How much time is this?
High tides occur 12 hours and 25 minutes apart. It takes six hours and 12.5 minutes for the water at the shore to go from high tide to low, or from low tide to high. For example, if a high tide occurs at 6 a.m., the next low tide will be at 12:12 p.m.; the next high tide will be at 6:24 p.m. and the last low tide will be at 12:36 a.m.Topic #2: Many beaches have natural or manmade sand dunes, and many have sea grass growing on them. Does this beach have sand dunes? If so, is there grass growing on the dune?
1. What is a sand dune?
A sand dune is a hill of loose grains of sand.
2. What natural sources create sand dunes?
Sand dunes are built by the actions of wind or the flow of water or both. Grains of sand are tiny and very light, so they are easily moved by the flow of wind and by water. Dunes occur in different shapes and sizes.
3. Name two purposes that sand dunes serve?
3.1 Dunes are important in protecting the land against potential ravages by storm waves from the sea, which can include flooding and destruction of houses and roads because of the weight of the water and force of the wind on the water.
3.2 Dunes can provide a home to birds, insects and reptiles.
4. What are two good reasons for planting dune grass on sand dunes?
4.1 By anchoring shifting sand and slowing down coastal winds, dune grass creates a place where other plants can grow more easily.
4.2 Its roots also help hold sand in place so it is harder for wind and water to move the sand away from the dune.Topic #3: Take a walk along the beach and see if you find seashells that have washed ashore.
1. What part of an animal’s body is the seashell?
A seashell is a hard, protective outer layer created by an animal that lives in the sea. The shell is part of the body of the animal.
2. Chances are the shell is empty. Why is that?
The shells are empty because the animal has died and the soft parts have been eaten by another animal or have decomposed.
3. What kinds of animals that live in the ocean have shells?
Clams, barnacles, horseshoe crabs, sea urchins and lobsters.
Topic #4: While at the beach, you may be lucky enough to see a school of dolphins swim by.
1. Why can dolphins survive on the surface of the ocean, when other fish must stay below the surface?
They are aquatic (meaning water inhabitants) and they are mammals, which means they breathe in air. They can go underwater but need to come back to the surface for air.
2. How do dolphins keep warm when in cold water?
They have a layer of blubber (fat) just beneath their outer skin.
3. Guess how fast in miles per hour a dolphin can swim?
Thirty four miles per hour.
4. What do you call a male dolphin, female dolphin and a baby dolphin?
Hint: Same names as for a male cow, female cow and baby cow. Male is a bull; female is a cow; baby is a calf.
Topic #5: It is very likely that you will see birds at the beach, and most likely some will be seagulls.
1. What colors do most seagulls have?
Usually grey or white, often with black markings on the head or wings.
2. What do the noises they make sound like? (Ex. sweet chirping, pleasant melodious, or harsh and ugly?)
Harsh wailing or squawking calls
3. What do seagulls like to eat?
Live food that often includes crabs and small fish, or any human food brought to the beach. We hope your family enjoys your visits to the beach, and that this article will encourage all of you to have some enjoyable science-oriented learning experiences.
#1 Wikipedia contributors, “Tide,” Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=Tide&oldid=892048557 (accessed April 12, 2019).
#2 Wikipedia contributors, “Dune,” Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=Dune&oldid=891938498 (accessed April 12, 2019).
#3 Wikipedia contributors, “Seashell,” Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=Seashell&oldid=890860111 (accessed April 12, 2019).
#4 Wikipedia contributors, “Dolphin,” Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=Dolphin&oldid=887712940 (accessed April 12, 2019).
#5 Wikipedia contributors, “Dolphin,” Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=Dolphin&oldid=887712940 (accessed April 12, 2019).