Winds, Tides and Currents
Driftwood Journey Curriculum
Lesson Summary
Objective: To show students the role currents, tides and winds play in depositing driftwood onto beaches.
Outcomes:
- Students will understand there are different currents in the ocean that play a role in how driftwood is transported.
- Students will understand winds play a role in how currents flow.
- Students will understand there are low tides and high tides, and their role in depositing driftwood on beaches.
- Students will understand the role of the moon’s gravitational pull on tides.
- Students will understand that their grandparents knew about winds, currents and tides, and used the information to figure out best places to collect driftwood.
Materials needed:
- Glass 9" x 12" baking dish; fan; food color; ice cube trays; pitcher; access to the beach; map of ocean currents, bottles with lids or corks; paper and pencil; globe
People to be included: Elders
Process
Gear up: Show students map of ocean currents and tell them about beach toys and/or Nike shoes that fell off a barge and ended up in different parts of the world, including Alaska. Tell them water movement in the ocean is caused by winds, currents and tides.
Explore: Activity #1: Tell students that wind plays a role in ocean currents and wave action. Winds blowing on the surface of the ocean push the water. The stronger the wind, the faster the water moves and the bigger the waves created.
Set up an electric tabletop fan on a tabletop. Ask students to gather around the table and hold their hands in front of the fan. Turn on the fan at the lowest setting, letting students feel the air flow. Turn the fan to a higher setting, and after a few seconds turn it up to the highest setting. Ask the students what they felt. Did the fan feel like the wind? Did the wind from the fan become stronger?
Fill a baking pan with water and set it on the tabletop in front of the fan. When the water has settled, tell students to watch the water in the pan very closely. Turn on the fan at the lowest speed. (If nothing happens to the water, raise the pan higher by placing it atop something and turn the fan on once more after the water has settled.) Ask students what they see happening to the water surface. Turn the fan to the higher setting and then after a few seconds to the highest setting. Ask students to describe what happened to the surface of the water.
Put a leaf (or anything else light that floats) into the pan of water. Repeat the above exercise.
Generalize: Ask students if they have ever felt the wind blowing really hard. Ask them if they ever looked at the ocean when it was that windy. Were there more or fewer waves? Do they think there is more driftwood or other objects on the beach the day after the water is calm or the day after there are a lot of waves.
Explore: Activity #2: Tell students that currents in the ocean are also affected by the temperature of the water. Tell them that cold water sinks and warm water rises and that the cold water can push aside the warm water. Tell them that the water is cold at the North Pole and South Pole and that it is warm at the equator. Tell them that because of the different temperatures water moves throughout the oceans and we call these movements currents.
The day before the experiment, divide students into groups, and have each group prepare for the activity by mixing food dye into water, pouring the water into an ice cube tray, and freezing it.
Display a globe and have students observe that all the oceans on Earth are connected to form one “world ocean.” Ask them where they think the water would be warmer — near the equator or near the poles. Then tell students that they are going to perform an experiment to demonstrate how the colder waters nearer the poles and the warmer waters nearer the equator mix together and move to create ocean currents.
The students in each group should fill a clear baking dish with warm tap water to represent the warm water near the equator. Instruct students to place one ice cube at each end of the baking dish, representing the cold water near the poles. Invite them to predict what will happen as the ice cubes melt.
Students will observe that the cold (colored) water sinks and moves along the bottom of the baking dish toward the warmer water in the middle; the warmer water moves toward the ends of the baking dish; as the cold water begins to warm, it begins to rise.
Ask students to make drawings of their experiment, with labeled diagrams. If their diagram were the world, where would the North and South Poles be and where would the Equator be?
Explore: Activity #3: Tell students that ocean currents are important to marine life, and to people. One fun way to use currents is to put a message in a bottle, put the bottle in the ocean and see where it ends up. Ask students to write a note about what they’ve learned so far. Tell them to put their name and mailing address at the end of the note, and at the very end to write: “If you find this, please send me a postcard in the mail.” Ask them to roll up their notes and to slip them into a bottle that has a lid or a cork. (For this exercise, one bottle may be used for every three or four messages.)
Generalize: Ask the students where they think their bottles will end up. Ask them if they have ever found a message in a bottle.
Explore: Activity #4: Tell students that their ancestors depended on driftwood that they found on beaches called “catcher beaches.” Ask them if they know why they are called that. Tell them that when a family found driftwood they wanted, but it was too heavy to move, they marked the piece by putting rocks on it to claim it until they were able to get help to move the wood. Ask them if they have ever seen anyone do that.
Tell them they will be going out to the beach. There, they will take about 15 minutes to examine the beach and make mental note of what sorts of things they find, aside from wood. Then they will take another 15 minutes to gather interesting pieces of driftwood that they will take back to the classroom/camp for carving, painting, mobiles and inspiration for poetry.
Tell them to put on appropriate gear (raingear and boots if raining) and to take an empty backpack if they have one (for wood and other finds). Take them to the beach.
Tell them also to take note of where the tide is when they get there and where it is by the time they leave. Tell them they can mark it somehow when they arrive with a big rock or by putting a stick vertically into the sand. Remind them to check just before they leave the beach what happened to the rock or the stick. Also remind them again of how much time they have to observe and to gather.
After they have gathered the driftwood, ask them to gather around the Elders who have come along. Ask the Elders to identify beach resources at the various beach zones (upper-tidal, mid-tidal and lower-tidal). Ask Elders to talk about the use of the resources and when, where and how they are harvested.
Explore: Activity #5: Back at the camp/classroom, pass out a template for a beach mural and ask them to draw a picture of what they learned from the Elders. What resources were found at low tide, mid tide and high tide?
After they finish the mural, ask students to write or draw a thank you to the Elders.
Lesson Outline:
1. A Driftwood Story
2. Properties of Wood
3. Cultural Uses of Wood – Past and Present
4. Tides – Gravitational Pull of the Moon
5. Wind, Tides and Currents
6. Earthquakes and Tsunamis
7. Afognak and the 1964 Tsunami
(Camp version, classroom version)
8. Celebration of Trees
• Driftwood Art
• Driftwood Stories and Poems
9. Celebrating Alutiiq Customs and Traditions
Appendix: Resources Used
