APES Unit 4: Module 19

Core

The innermost zone of Earth’s interior, composed mostly of iron and nickel. It includes a liquid outer layer and a solid inner layer

Mantle

The layer of Earth above the core, containing magma, and he asthenosphere, and the solid upper mantle

Magma

Molten rock

Asthenosphere

The layer of Earth located in the outer part of the mantle, composed of semi-molten rock

Lithosphere

The outermost layer of Earth, including the solid upper mantle and crust

Plate tectonics

The theory that the lithosphere of Earth is divided into plates, most of which are in constant motion

Earthquake

A sudden movement of Earth’s crust caused by a release of potential energy from the movement of tectonic plates

Hot spot

In geology, a place where molten material from Earth’s mantle reaches the lithosphere

Volcano

A vent in the surface of Earth that emits ash, gases, or molten lava

Tsunami

A series of waves in the ocean caused by seismic activity or an undersea volcano that causes a massive displacement of water

Divergent boundary

An area below the ocean where tectonic plates move away from each other

Seafloor spreading

Caused by a divergent boundary in which rising magma forms new oceanic crust on the seafloor at the boundaries between those plates

Convergent boundary

An area where one plate moves toward another plate and collides

Subduction

The process in which the edge of an oceanic plate moves downward beneath the continental plate and is pushed toward the center of Earth

Island arc

A chain of islands formed by volcanoes as a result of two tectonic plates coming together and experiencing subduction

Collision zone

An area where two continental plates are pushed together and the colliding forces push up the crust to form a mountain range

Transform boundary

An area where tectonic plates move sideways past each other

Fault

A fracture in rock caused by a movement of Earth’s crust

What are the layers of Earth?

The center of Earth has a solid core that is surrounded by a liquid core. Outside of these layers in the magma, the asthenosphere, and the lithosphere

How does tectonic plate movement produce divergent, convergent, and transform boundaries?

Tectonic plates are continuously moving as the underlying magma circulates and they interact at convergent, divergent, and transform boundaries. The movement if these plates over millions of years has caused dramatic changes in biodiversity around the world. The planet remains very hot at its center and this heat causes plumes of hot magma to well upward from the mantle to produce volcanoes and hot spots. Earthquakes occur where jagged edges of plates rub together and the mounting pressure causes the plates to ultimately slip. When this happens, the plates can move up to several meters in just a few seconds and cause tremendous destruction to human property and lives

How does this global distribution of late boundaries predict the location of certain geologic events?

Earthquakes and volcanoes are concentrated in the areas around plate boundaries. Volcanoes can also be found away from these boundaries where there are hot spots of magma flowing up to the surface of Earth, such as the hotspot they formed the Hawaiian Islands