There is change happening all around us.  Every second big changes and little changes are morphing what we sense of our world. In 7th grade we, learned about the little changes, so small not even we could see them.  We learned about the air vibrating, making sound, and tiny chemical reactions like rust happening every day.  Then, going into 8th grade we learned about big changes, changes so big that we couldn’t even see them.  Although these changes were happening right under our nose, some of us had no idea that they even occurred. Some of these big chances are due to plate tectonics.  This year in 8th grade I’ve grown in my knowledge of plate tectonics shaping our world, specifically my knowledge of the Mid-Atlantic Ridge.  

​

Plate tectonics is occurring at this very moment. It’s all happening under our feet. The earth has four layers.  At the middle, there is the core which is two layers, the inner core and the outer core. Surrounding the outer core is the mantle. Then floating on top of the mantle is the earth’s crust. Plate tectonics mainly happens in the outer 2 most layers.  The mantle is non-Newtonian fluid. This means it is not 100% a solid nor a fluid. For the most part it acts as a fluid. The mantle is heated by the core. In the mantle is mainly compressed crust that has been submerged. The crust on the earth that we stand on is actually huge floating “slabs” of crust. These huge “slabs” are called tectonic plates. There are actually two types of crust, Oceanic crust and Continental crust. Oceanic crust is thinner and more rigid while Continental crust is thicker and less rigid. These two types of crust are caused by different movements of tectonic plates. The crust I am going to focus on is Oceanic crust; since this is the type of crust at the Mid-Atlantic Ridge (MAR).  

At the MAR, there are tectonic plates moving away from each other. This is due to mantle convection. Mantle convection is a phenomenon that occurs when the mantle is heated by the core. Since heat rises   a heated thing becoming less dense the rock closest to the core rises upward toward the crust. As this rock floats farther away from the heat source it becomes cooler and denser. This causes the rock to fall back down toward the mantle. This process creates circular currents accruing in the mantle. At the MAR, there are two mantle convection currents, both turning away from each other.  On top of the mantle tectonic plates move in whichever direction the currents flow. This means at the MAR the plates are moving away from each other. This is called an Oceanic diverging boundary since it is occurring in oceanic crust. We learned this through IQWST and other simulations.  

Once we understood most of the content we started the plate tectonic project. This is a project where groups of three create 3-D models for teachers in other school districts to use in class. Each group is assigned a different plate tectonic boundary. My group was the MAR. At the beginning of the project I didn’t completely understand how the MAR tectonic boundary worked. Mainly, I didn’t understand how the ridge was created. At the beginning of the project we had to draft how we thought we might be able to make a model. In my draft, I had two plates moving away from each other and a ridge rising out of it. In the draft I made to show my group you can see that when the question “ What are the important land and ocean floor features that are created as a result of this motion?”, I answered “A ridge comes up out of the mantle”. This actually represents how an island, not a ridge. As the process went on my group had to problem solve and revise our model many times. By the end of the project we had a completed 3-D model accurately representing a phenomenon that occurs at ocean ridges called sea floor spreading. This is when two oceanic plates move away from each other creating a space that is filled in by the mantle. This creates new crust due to hot mantle rock filling in the gap and cooling down. This means that the newest crust is closest to the ridge. You can see in our model when you pull apart the two plates new plates come out with it. This new plate is duct-tape coming out of the mantle. The plate you see most recently represent the most recent crust created. This model will help teachers teach other students about plate tectonic boundaries so they don’t have the same misconceptions at the start of this project.  

​

This information will help others in the future this model might help inspire kids learning about plate tectonics to go on and study in this field. This project has also helped me learn more about plate tectonics. It showed me and helped me understand how mantle spreading occurs at the MAR.