Now that we've figured out convention's role in plate movement, we're putting everything together! We created a "Gotta Have it Checklist!" with everything we know plays a factor in getting Everest to get taller and shift one direction annually, and another direction during an earthquake!
After figuring out just how hot the core of the Earth is, we thought that this heat would help us figure out the cause behind the movement of the earth's plates. We also figured that NOW would be a good time to develop a physical model, especially since we already know so much about thermal energy transfer from our cups unit.
Building out a physical model was tough. We don't have anything to resemble molten rock in our classroom, and getting a whole bunch of putty (similar to molten rock) would be expensive. We settled on water and are cognizant of its limitations (but we're okay with that! We also realize that using any heat source available to us at school is a very small fraction of the amount of energy coming from the earth's core, but we're okay with that, too!
So using some tubs of water, some mugs of hot water under them, and some food coloring, we created this model of the core and mantle of the Earth!
Because of the limitations of the model, we set out to find a "better" one, one where there was actually some of the Earth's crust evidence, a "thicker" mantle, and a greater energy source! We found something! (Heating oil with parsley on top!)
From both of these models, we're able to see the same energy transfer from heat through the matter in the mantle. This process we are calling convection...and from the top and side views, we are starting to see how this can affect plate movement on top of the mantle! We built out a model and are truly starting to see how convection currents cause plates to come apart, move towards each other, or differ in speed and direction. Now can we use this model to explain what is happening at Mt. Everest?!?!
So after figuring out that plates are made of bedrock, and that different things can be on top of bedrock, we are pushing to understand plates more! We developed some initial models, only to uncover that we still need more help in understanding them!
We turned back to the seismic simulator to see cross-sections (or a side view) of the plates. This is enabling us to see just how deep earthquakes are compared to one another (as they can be measured at the surface and deep down)!
With a little help from some research, we're able to see just what is below the earth's plates, and the thermal energy associated with each layer. Since we're figured out a lot about thermal energy this year during our cups unit, we're seeing the connections between thermal energy transfer from the core of the earth to the outermost layer where plates are. We redeveloped the model of the earth and are thinking about what we need to figure out next!
Our photographic evidence from both plate boundaries and non-plate boundaries is really helping us see why the landscape of the Earth is just so different. We noticed some patterns--like where plates come towards each other, we have raised land, like mountains or cliffs (even in water). We also see how the land can split or crack, where plates seem to be moving away from one another.
Regardless of all these differing landscapes, we see lots of different coverings at these locations--pure rock, water, trees, grass, soil, etc. Digging deeper, we realize that all of these places, at different depths, contain something called bedrock. We pulled out some samples of bedrock to help us better understand more about plates. Bedrock is certainly hard, but it has different densities and colors. All this plate talk is making us think deeper about plates...like what must they really look like...how do they differ...how does this impact the earthquakes that happen...
With so many questions regarding the cause of earthquakes, we read some articles that helped us better understand what was the cause of so many earthquakes all over the world. We figured out the following through our research:
1. The surface of the earth is called the crust. It is made up of broken pieces scientists called plates.
2. These plates can collide with each other. When they move past one another, an earthquake happens at a plate boundary.
With a whole bunch of plate data, we were able to see that plates...
a. Move in different directions.
b. Are different sizes.
c. Move at different speeds!
This opened up a WHOLE BUNCH of new questions, focused on plates!
We saw some differences, too, between locations. Those differences included magnitudes and the appearance of volcanoes and tsunamis. We're wondering what's causing these earthquakes to happen in the first place and then what makes each of these earthquakes different. Like does one earthquake cause another to happen, like a chain reaction? Do these so called plates bump into each other? And what even is a "plate" that some of our classmates are talking about? How do earthquakes even get the energy to happen? And mountains are almost always nearby, so how is there enough energy to even get a mountain to move in the first place? And some parts of the ocean have "mountains" under the water...will these places end up with mountains above water one day if these earthquakes continue? Do earthquakes even make mountains?
We've got so many more questions...!!!
We did agree we need to figure out the causes of earthquakes next...
How can Mt. Everest...
1. Move 4 cm NE each year?
2. Move back 3-4 cm SW during a seemingly random earthquake?
3. Grow taller 6-7 cm a year?
Gosh we have a lot of figuring out to do!
Here are our initial models and related phenomena lists...
And all these things (along with a really cool simulator showing us stuff about earthquakes led to all these questions!
So from all our questions, we began thinking about investigations we could do along with data we could gather to figure out all the answers to our questions...
And the resounding starting place is to figure out more about earthquake patterns, locations, and causes...