The earth's continents are constantly moving due to the motions of the tectonic plates. Closely examine the map below, which shows the 15 major tectonic plates.
As you can see, some of the plates contain continents and others are mostly under the ocean. The type of crust that underlies the continents is called continental crust, while the type found under the oceans is called oceanic crust. Continental crust is thicker — about 20 to 40 miles (35 to 70 km) thick — and usually older than oceanic crust, which is only 4 to 6 miles (7 to 10 km) thick. All the plates have names, usually referring to landmasses, oceans, or regions of the globe where they are located.
The border between two tectonic plates is called a boundary. All the tectonic plates are constantly moving — very slowly — around the planet, but in many different directions. Some are moving toward each other, some are moving apart, and some are sliding past each other. Because of these differences, tectonic plate boundaries are grouped into three main types.
Use the map below to see where the three different types of plate boundaries are found throughout the world.
First, find the KEY in the green box located in the lower right-hand corner of the map. Then, roll your mouse over each boundary name in the KEY to see its location.
Image credit: Maps based on illustrations created at the University of Sydney and by the NASA/Goddard
Space Flight Center Scientific Visualization Studio. The map at the bottom of the page shows approximate locations of the tectonic plate boundaries.