Plate tectonic is the theory which tell us that earth's outer layer is made up of plates which has moved throughout the history. If we see back then in 225 million years ago, all the continents were once together and a big giant continent known as Pangaea. Plate tectonic theory begin when Alfredo Wegener proposed the theory of "Continental Drift." This showed that the outlines of many coastlines look like they fit together like a puzzle. The evidences were found such as fossils, mountains, and rocks when all the continents were together. However, over time, continents started to break up into smaller continents during the Jurassic and Cretaceous Period. Then by the end of the Cretaceous period, all the continents got separated in to 7 continents which we see today.
Evidence 1: Plate Boundaries
Three types of plates boundaries are characterized by the way the plates moves relative to each other. They are associated with the different types of surfaces and movements.
- Convergent Boundary: This occurs when two plates slide towards each other. This may form Subduction zone where the dense plate which is oceanic goes under the continental plate. An example can be Deep marine trenches.
- Divergent Boundary: This occurs when two plates slide apart from each other. An example can be Mid-ocean ridges.
- Transform Boundary: This occurs when two plates slide past each other. An example can be San Andreas Fault in California.
Evidence 2: Convection Current Lab
This lab showed us that how water movements cause the convection currents. I did a lab in the class using hot water, cold water and food coloring. When I added the food coloring in the water, the cold water make the food coloring to sink down and hot water make the food coloring to rise upwards. This kept happening by going up when it reached the hot water and then again going down when it reached the cold water. Cold water represented the crust and hot water represented the outer core. Convection within the earth's mantle pushes the plates because mantle is below the crust so this makes the plates to move.
Evidence 3: Faults
Fault is a break in the land. Fault can cause a movement in the earth.
- Normal Fault: This occurs when one side of the surface moves downwards because rocks are pulled apart.
- Reverse Fault: This occurs when one side of the surface moves upwards because rock are forced together through compression.
- Strike-slip Fault: This occurs when two surfaces slide past each other.
Conclusion:
In my opinion, plate tectonic theory is agreeable because as we see in the evidences, it proves the movement of earth. Earth have been and still moving consistently. Many million years ago, earth wasn't the same as it is today because the plate have moved. Some of the topics which proves the movement of earth are faults, plate boundaries, and convection currents. Therefore, plate tectonic theory is correct.
Reflection:
1. What did you enjoy most about this project and why?
I enjoyed working individually because I had the option to chose any topic from the list and do the things in my own way. I also enjoyed by doing the convection current lab because it was kind of interesting and cool when I saw how the food coloring was going up and down.
2. What was most challenging for you during this project and why?
The most challenging part was to manage the time for each activity because we had to do the different activities in the given time. Another challenging part for me was to make the mini lab because we had to make sure that the lab shows the understanding toward the topic and questions should be good.
3. What new skills did you learn from doing this project?
The new skills I learned during this project was how to manage my time very well. I also learned how to use the beam-balance which will help me in my future if I will get a chance to work with it again.
4. Is there anything that you could have done to improve any of your work? Explain.
I could have re-check my answers again to make sure that they are correct.
5. What would you change about this project?
I would choose a different topic so that I can learn another thing. I would also choose a different activity so that I can get a chance to do more fun things.