How Do Plates Interact with Each Other? LESSON 5.1 AND 5.2

What are the different ways that plates could move with one another where they meet at plate boundaries? What do you think happens on Earth’s surface when these kinds of movements happen? ACTIVITY 5.1: WHAT HAPPENS WHEN PLATES MOVE?

WHAT KIND OF PATTERN DO YOU SEE IN THIS PICTURE?

Each of you will get 1 sheet of graham crackers and 1 cube of jello Break your sheet of crackers in half Put your cube of jello on one of the crackers Place the 2 cracker squares next to each other. The graham crackers should be touching Slowly and gently, slide the crackers past one another while keeping the crackers touching PROCEDURES

What did you observe? What does the gelatin represent? What do the graham cracker represent? What have you simulated?

How did the plates move? What happens when the plates kept moving toward each other? What happens when 2 plates move toward each other? What happens when 2 plates move alongside each other? atch?v=kwfNGatxUJI atch?v=kwfNGatxUJI VOLCANO SIMULATION

What are the 2 types of convergence that you have seen? Why do you think that sometimes plates slide under other plates, and sometimes they do not? What would the Earth look like if there was no water on its surface? CONVERGENCE

There is a lot of relief on Earth’s surface. There are two major average elevations—the elevations of the continents (higher elevations) and the elevations of the ocean floors (lower elevations). Oceanic plate material refers to plates that have oceanic rock on the top edges of the plates. Oceanic plate material is relatively thin. Continental plate material refers to plates that have continental rock on the top edges of the plates. Continental plate material is relatively thick. Water collects in the oceans because it has lower elevations compared to the continental landmasses.

Plate TypeRock TypeRelative Thickness Rock Density ContinentalGraniteThicker2.65 g/mL OceanicBasaltThinner3.01 g/mL DENSITIES OF TECTONIC PLATES

Our understanding of Earth’s surface became slightly more complex as scientists realized that the rock that makes up the ocean floor is a different than the rock that makes up the continental landmasses. The main difference is that the rocks of the ocean floor are not only thinner but also denser. The rocks of the continental landmasses are both thicker and less dense. Can you figure out why when two plates collide, sometimes one plate slides under another, and sometimes the plates crumple up and form mountains?

When the edges of two continental plates converge, neither one will go below the other. Both plates stay at the surface and crumple to form mountains very slowly over long periods of time. When the oceanic plate subducts below the continental plate, it becomes even denser. This makes it sink in farther and pulls the rest of the plate in behind it.