Moving Plates

The Earth’s crust is composed of several huge, solid sections, called plates. The Earth’s crust is composed of several huge, solid sections, called plates. These plates move slowly as they float on the semi-liquid below. These plates move slowly as they float on the semi-liquid below.

There are 7 major lithospheric plates: There are 7 major lithospheric plates: Indian-Australian Indian-Australian Pacific Pacific North American North American South American South American Antarctic Antarctic African African Eurasian. Eurasian.

There are 8 minor lithospheric plates: There are 8 minor lithospheric plates: Antarctic Plate (although some consider this to be a major plate!) Antarctic Plate (although some consider this to be a major plate!) Arabian Plate Arabian Plate Caribbean Plate Caribbean Plate Cocus Plate Cocus Plate Juan de Fuca Plate Juan de Fuca Plate Nasco Plate Nasco Plate Indian Plate Indian Plate Philippine Plate Philippine Plate

Movement of Plates The plates are moving relative to one another. The plates are moving relative to one another. For example the plates that carry North America and the plate that carries Europe are moving away from each other. For example the plates that carry North America and the plate that carries Europe are moving away from each other. Wherever plates meet, earthquakes signal their movement. Wherever plates meet, earthquakes signal their movement.

Most Earthquakes occur at the edge of continental and oceanic plates. Most Earthquakes occur at the edge of continental and oceanic plates. Many of the Earth’s earthquakes occur in the Pacific Ocean around the “Ring of Fire” Many of the Earth’s earthquakes occur in the Pacific Ocean around the “Ring of Fire”

Mid Atlantic Ridge The Mid-Atlantic Ridge (MAR) is a mid ocean ridge, a divergent tectonic plate boundary located along the floor of the Atlantic Ocean. The Mid-Atlantic Ridge (MAR) is a mid ocean ridge, a divergent tectonic plate boundary located along the floor of the Atlantic Ocean. It separates the Eurasian Plate and North American Plate in the North Atlantic, and the African Plate from the South American Plate in the South Atlantic. It separates the Eurasian Plate and North American Plate in the North Atlantic, and the African Plate from the South American Plate in the South Atlantic.Eurasian PlateNorth American Plate African PlateSouth American PlateEurasian PlateNorth American Plate African PlateSouth American Plate

Slipping By: A Fault A fault occurs in a place on the Earth’s crust where plates are slipping past each other. A fault occurs in a place on the Earth’s crust where plates are slipping past each other.

Collision: Subduction Plates collide as they move toward each other. Plates collide as they move toward each other. When they collide one plate slides below the other. As the lower plate plunges underneath it pushes into the hot mantle, heats up and melts. When they collide one plate slides below the other. As the lower plate plunges underneath it pushes into the hot mantle, heats up and melts.

Separation: Ridges In the places where the plates are moving apart from one another, hot magma rises up into the crack between the plates and hardens, forming ridges of new rock. In the places where the plates are moving apart from one another, hot magma rises up into the crack between the plates and hardens, forming ridges of new rock.