Layers of the Earth and Tectonic Plates

Flashcards covering key concepts related to layers of the earth, tectonic plates, and geological processes.

Lithosphere

The rigid outer layer comprising the crust and the uppermost part of the mantle.

Asthenosphere

The semi-fluid layer located below the lithosphere, containing hot, molten rock or magma.

Tectonic Plates

Large and small sections of the lithosphere that interact to create tectonic activities.

Convection Currents

The movement generated by the hot lower mantle rising and cooling materials moving downward, driving tectonic plate movement.

Continental Crust

The crust that makes up the continents, consisting of light granitic rocks.

Oceanic Crust

The crust that underlies the ocean floor, made of dense basaltic rocks.

Primary Waves (P waves)

Compressional body waves that travel through the earth at varying speeds and shake the ground back and forth.

Secondary Waves (S waves)

Transverse waves that move perpendicular to the direction of the wave and cannot travel through liquids.

Seismic Waves

Energy waves produced by earthquakes that move outward from the focus.

Plate Tectonics

The theory describing the movements of large slabs of Earth's crust.

Pangea

A supercontinent that existed in the geological past, surrounded by the Panthalassa ocean.

Seafloor Spreading Theory

The theory stating that ocean floors move and carry continents along, occurring at divergent plate boundaries.

Divergent Boundaries

Regions where two tectonic plates move away from each other, creating gaps that can lead to rift valleys.

Convergent Boundaries

Regions where two plates slide toward each other, forming either subduction zones or mountain ranges.

Transform Boundaries

Regions where tectonic plates slide past one another, causing earthquakes.

Orogenesis

The process of mountain formation due to the collision of tectonic plates.

Normal Fault

A dip-slip fault where the hanging wall slides downward in relation to the footwall.

Reverse Fault

A dip-slip fault where the block of Earth's crust moves upward along the dip angle.

Epicenter

The point on Earth's surface directly above the focus of an earthquake.

Focus/Hypocenter

The point within the Earth where rocks break and seismic energy is first released.

Fault-Block Mountains

Mountains formed by the uplift of large blocks of crust due to normal fault movement.