Earth Science Vocabulary

the rigid outer layer of the Earth, including the crust and the upper mantle

• Lithosphere
• Seafloor Spreading
• Tectonic Plates

a weak plastic-like layer of the mantle below the lithosphere where convection currents flow

• Asthenosphere
• Lithosphere
• Divergent Boundary

the innermost layer of the Earth, located beneath the mantle; hottest, densest layer

• Core
• Asthenosphere
• Convergent Boundary

the thickest layer of the Earth’s interior, located between the crust and the core

• Mantle
• Focus
• Normal Fault

 thin, brittle, rocky outer layer of Earth

• Crust
• Convection Currents
• Core

the transfer of heat within the mantle in a circular flow, causing tectonic plates to move slowly over time

• Convection Currents
• Crust
• Mid-Ocean Ridge

a boundary in which two plates move toward each other

• Convergent Boundary
• Subduction
• Lithosphere

a boundary where two plates are separating or moving apart, common at oceanic ridges 

• Divergent Boundary
• Reverse Fault
• Convection Currents

a boundary where two plates slide past each other

• Transform Boundary
• Core
• Focus

the process by which a more dense tectonic plate sinks below a less dense plate at a convergent boundary

• Subduction
• Tectonic Plates
• Crust