Earth’s Terms Test
Crust – the thin and solid outermost layer of the Earth, above the mantle
Mantle – the layer of rock between the Earth’s crust and core
Core – the central part of the Earth below the mantle
Lithosphere – the solid, outer layer of the Earth that consists of the crust and the
rigid upper part of the mantle
Asthenosphere – the soft layer of the mantle on which the tectonic plates move
Mesosphere – the strong, lower part of the mantle between the Asthenosphere
and the outer core
Tectonic Plate – a block of lithosphere that consists of the crust and the rigid,
outermost part of the mantle
Continental Drift – the hypothesis that states that the continents once formed a
single landmass, broke up, and drifted to their present locations
Sea Floor Spreading – the process by which new oceanic lithosphere forms as
magma rises toward the surface and solidifies
Plate Tectonics – the theory that explains how the tectonic plates move and
change shape
Convergent Boundary – the boundary formed by the collision of two ltihospheric
Divergent Boundary – the boundary between two tectonic plates that are moving
away from each other
Transform Boundary – the boundary between tectonic plates that are sliding past
each other horizontally
Compression – the stress that occurs when forces act to squeeze an object
Tension – stress that occurs when forces act to stretch an object
Folding – the bending of rock layers due to stress
Fault – a break in a body of rock along which one block slides relative to another
Uplift – the rising of regions of the Earth’s crust to higher elevations
Weathering – when rocks are broken down into smaller fragments
Erosion – when rock fragments are moved by some force of nature
Deposition – when rock fragments are laid down in a new location
Igneous rock – formed by cooling and hardening of hot liquid rock
Sedimentary rock – formed when sediments are pressed and cemented together
Metamorphic rock – formed when rocks are changed by heat and pressure
P waves – a seismic wave that compresses and expands rock, fastest wave
S waves – a seismic wave that causes rock to move in a side-to-side direction
Surface waves – these seismic waves travel more slowly, but are more destructive
Seismic waves – a wave of energy that travels through the Earth, away from an
earthquake in all directions
Seismology – the study of earthquakes
Seismologist – someone who studies earthquakes
Seismogram – the print out of earthquake activity, shows the p, s, and surface
Seismograph – an instrument that records seismic waves
Focus – the point inside the Earth where the earthquake begins
Epicenter – the point on the Earth’s surface directly above an Earthquake’s
starting point, or focus
Fault – a break in a body of a rock in which one block slides relative to another
Elastic rebound – the sudden return of elastically deformed rock to its
undeformed shape
Deformation – the bending, tilting, and breaking of the Earth’s crust
Richter scale – measures earthquake intensity on a scale of 1-10
Mercalli intensity scale – measures earthquake intensity and the amount of
damage caused by an earthquake
Earthquake – the shaking of the ground
Aftershock – minor shocks following the main shock of an earthquake
Tsunami – a large wave that results from large-scale seafloor displacements
associated w/ large earthquakes
Volcano – a vent or fissure in the Earth’s surface through which magma and gases are expelled
Vent – an opening at the surface of the Earth through which volcanic material passes
Magma Chamber – the body of molten rock that feeds the volcano
Crater – a funnel shaped pit near the top of the central vent of a volcano
Caldera – a crater that forms when the ground sinks around the vent
Rift Zone – area of deep cracks that forms between two tectonic plates that are pulling away
Hot spot – a volcanically active area of Earth’s surface far from a tectonic plate boundary
Ring of Fire – an area of volcanic activity that borders the pacific plate
Shield Volcano – built by layers of lava, non explosive eruptions
Cinder Cone Volcano – pyroclastic material, steep slopes, moderately explosive
Composite Volcano – explosive eruptions and quiet flows
Lava – liquid magma that flows from a volcanic vent

Earth`s Terms Test PLATE TECTONICS Crust – the thin and solid