Sec.: __ Name: _. .__ Experiment: Waves, Currents, and Coastal Features (E. Science 9-9-3d) Purpose: To construct a simple wave tank, to observe some of the coastal features that form as waves interact with sloping sandy shorelines, underwater obstacles, and other topographic landforms. Materials: rubber stopper or rock , grease pencil sand (clean) chalk powder wave tank wooden block (15 x 3 x 7 cm wave generator) Methods: 1. Make a beach on one end of the wave tank. See simulation A. 2. Using a grease pencil, make two marks 10 cm apart on the edge of the wave tank. See simulation A. (10 cm from "ocean" edge the 10 cm more). 3. Fill the wave tank with water to a depth of 3 cm. 4. Hold the wooden block in the water so that it is just touching the bottom of the wave tank and is parallel with the mark that is farthest away from shore. Move the block toward the shore until it is parallel with the second mark. Lift the block out of the water. This entire motion should take about 1 second. Repeat the motion until you can produce uniform waves. 5. Once you are satisfied that you can produce uniform waves, set up the other simulation as illustrated in the diagrams. Each simulation will take at least 5 minutes. During that period of time, watch the waves and movement of sand particles. 6. For each simulation, mark on the diagrams the crests of waves as they approach the shore. Also indicate with the letter "e" where erosion is taking place and the letter "d) where deposition is taking place. Use arrows to indicate the direction of sand movement. 7. For simulation C, place some chalk powder in the water near the shore and watch its movement. This movement reflect the longshore current that you generated by changing the angle of the block (wave generator). Record direction of powder movement beside figure C. Results: SIMULATION B Headland rock (sea stock) Wove crest
Transcript
Sec.:__ Name: _. .__
Experiment: Waves, Currents, and CoastalFeatures (E. Science 9-9-3d)
Purpose: To construct a simple wave tank, toobserve some of the coastal features that form as
waves interact with sloping sandy shorelines,underwater obstacles, and other topographiclandforms.
Materials: rubber stopper or rock, grease pencil sand (clean)
chalk powder wave tankwooden block (15 x 3 x 7 cm wave generator)
Methods: 1. Make a beach on one end of thewave tank. See simulation A.
2. Using a grease pencil, make two marks 10 cmapart on the edge of the wave tank. Seesimulation A. (10 cm from "ocean" edge the 10cm more).
3. Fill the wave tank with water to a depth of 3 cm.4. Hold the wooden block in the water so that it is just touching the bottom of the wavetank and is parallel with the mark that is farthest away from shore. Move the blocktoward the shore until it is parallel with the second mark. Lift the block out of the water.This entire motion should take about 1 second. Repeat the motion until you canproduce uniform waves.5. Once you are satisfied that you can produce uniform waves, set up the othersimulation as illustrated in the diagrams. Each simulation will take at least 5 minutes.During that period of time, watch the waves and movement of sand particles.6. For each simulation, mark on the diagrams the crests of waves as they approachthe shore. Also indicate with the letter "e" where erosion is taking place and the letter"d) where deposition is taking place. Use arrows to indicate the direction of sandmovement.7. For simulation C, place some chalk powder in the water near the shore and watchits movement. This movement reflect the longshore current that you generated bychanging the angle of the block (wave generator). Record direction of powdermovement beside figure C.
Results:
SIMULATION B
Headland
rock
(sea stock)
Wovecrest
Inlet
Conclusions: Simulation A:
1. Describe the motion of the fine sand particles.
Jetties
Wovecrest
2. Predict what would happen if you continued the wave action for several days.
3. If you were able to increase (during winter condition) or decrease (during summercondition) the energy of the waves, what changes should you see in the character ofthe beach?increase:decrease:
4. Are the waves produced in simulation A deep or shallow (surface) water waves?
Simulation B:5. The island (sea stack) is the end re~ult of the headland eroding. Describe themovement of sand in the area behind the sea stack.
6. What topographic feature could be formed between the sea stack and theheadland? (see third page of lab).
Simulation C:7. What happened to the beach?
8. What happened to the inlet?
9. What topographic feature could be forming at the mouth of the inlet? (see third page)
10. If the longshore current continued for a long period of time, what would eventuallyhappen to the inlet?
Simulation D:11. What effect did the wood jetties have on the deposition of sand?
12. Why are jetties built on either side of an inlet?
13. What would happen if the jetties were shortened?
Sec.: Name: __ . _Discussion:
1a. According to Jeremiah 5:21-24, what is the purpose that God gave for theseashore?1b. What is this passage, in Jeremiah, trying to persuade the people of?
2_ What is the wisdom and breadth of understanding of Solomon compared to (I Kings4:29)?
3. Because Abraham and David were obedient to God's instruction, what does Godpromise about the number of dependents of each (Gen. 22:17, Jer. 33:22)?
4. Many different features can develop from the deposition of sediments in a shorezone. Study the following terms associated with shore erosion and deposition. Thenuse their descriptions to help you identify those features labplprl in tho ilh I~t,.<>ti,...••..•
barrier island - sand deposits that lay parallel to the shore but areseparated from the mainland.
bay - inlet of the sea that is usually smaller than a gulf.
headland - point of high land that juts out into the sea, a cape.
spit - load of sand that is deposited as soon as a longshore current turnsinto a bay.
bay barrier - spit that extends across the mouth of a bay cutting the bayoff from the sea.
lagoon - shallow pond that a bay can become when it is cut off from thesea.
tambala - sand deposit that forms in such a way that it connects anisland to the mainland.
