Unit 4: Plate Tectonics & Earth Layers - Study Guide for Geology

What is the lithosphere?

The lithosphere is the rigid outer layer of the Earth, consisting of the crust and the uppermost mantle.

What drives plate motion?

Plate motion is driven by mantle convection, slab pull, and ridge push.

Where do most earthquakes and volcanoes occur?

Most earthquakes and volcanoes occur at plate boundaries.

What are the layers of the Earth?

The layers of the Earth are the crust, mantle, outer core, and inner core.

What is mantle convection?

Mantle convection is the process where heat from the core causes mantle material to rise when hot and sink when cool, dragging tectonic plates.

What is Pangaea?

Pangaea was a supercontinent that existed when all continents were joined together.

What evidence supports the theory of continental drift?

Evidence includes the fit of continents, matching fossils, similar rock layers, and climate evidence.

What is seafloor spreading?

Seafloor spreading is the process where magma rises at mid-ocean ridges, cools, and forms new oceanic crust, pushing older crust away.

What happens at a divergent boundary?

At a divergent boundary, tectonic plates move apart, allowing magma to rise and create new crust.

What landforms are created at divergent boundaries?

Landforms include mid-ocean ridges and rift valleys.

What occurs at a convergent boundary?

At a convergent boundary, tectonic plates move together, leading to subduction, volcanoes, and mountain formation.

What are the three types of convergent boundaries?

The three types are oceanic-continental, oceanic-oceanic, and continental-continental.

What is a transform boundary?

A transform boundary is where tectonic plates slide past each other, causing faults and earthquakes.

What is a hot spot?

A hot spot is an area where mantle plumes cause volcanic activity, creating a chain of volcanoes as a plate moves over it.

Where do most geological disasters occur?

Most geological disasters occur along plate boundaries, especially convergent and transform boundaries.

What is slab pull?

Slab pull is a force that occurs when a sinking plate pulls the rest of the plate with it.

What is ridge push?

Ridge push is a force that occurs when gravity pushes plates away from mid-ocean ridges.

What is the difference between oceanic and continental crust?

Oceanic crust is thinner and denser than continental crust, which is thicker and less dense.

What is subduction?

Subduction is the process where one tectonic plate moves under another and sinks into the mantle.

What is a mid-ocean ridge?

A mid-ocean ridge is an underwater mountain range formed by plate tectonics at divergent boundaries.

What is a rift valley?

A rift valley is a lowland region formed by the divergence of tectonic plates.

What is the asthenosphere?

The asthenosphere is the semi-fluid layer of the mantle beneath the lithosphere, allowing for plate movement.