AP Environmental Science, Topic 4.1 (ERT-4.A.1 and 4.A.5). Watch an oceanic plate push into a continental plate, then see what the collision builds. When plates collide like this, the place where they meet is called a convergent plate boundary.
Cross-section about 350 miles wide and 200 miles deep. Mountain heights are exaggerated about 3×. The real motion is slow, about as fast as a fingernail grows (about 2 inches a year), so this animation speeds up time. Yellow dots are places where earthquakes can start inside the subducting plate. Orange blobs are magma.
Predict first
The two plates stick together while they keep moving, so stress builds. When it overcomes the friction, the boundary slips and releases the stored energy as an earthquake. Each whole step in magnitude is about 32 times more energy.
Swim with the arrow keys (or W, A, S, D), or use the buttons. Distances are exaggerated so every zone is easy to see. In real life a scuba diver can only go about 130 feet deep, and the pressure at trench depth would crush a diver, so scientists use strong submarines.
Hold the buttons or arrow keys to swim. Press B for the big picture. Swim near a creature to meet it.
Heights and depths are measured from sea level. Values are rounded.
Schematic model for teaching. Crust that is squeezed gets thicker and floats higher, like an iceberg, so mountains grow from rock the simulation actually compresses.