Geology Vocabulary – Part 1
Chapter 8
Pg. 210
energy: the ability to cause change
earthquake: movement of the ground that occurs when rocks inside Earth pass
their elastic limit, break suddenly, and experience elastic rebound
fault: fracture that occurs when rocks break and that results in relative movement
of opposing sides; can form as a result of compression (reverse fault), being pulled
apart (normal fault), or shear (strike-slip fault)
seismic wave: earthquake waves, including primary waves, secondary waves, and
surface waves
focus: point deep inside Earth where energy is released, causing an earthquake
epicenter: point on Earth’s surface directly above an earthquake’s focus
seismograph: instrument used to record seismic waves
magnitude: a measure of the energy released by an earthquake
tsunami: powerful seismic sea wave that begins over an ocean-floor earthquake,
can reach 30m in height when approaching land, and can cause destruction in
coastal areas
seismic safe: describes the ability of structures to stand up against the vibrations
caused by an earthquake
Pg. 219
plate: a large section of Earth’s crust and rigid upper mantle that moves around on
the lithosphere
volcano: cone-shaped hill or mountain formed when hot magma, solids, and gas
erupt onto Earth’s surface through a vent
lava: molten rock flowing onto Earths’ surface…
shield volcano: large, broad volcano with gently sloping sides that is formed by the
build-up of basaltic layers
cinder cone volcano: relatively small volcano formed by moderate to explosive
eruptions of tephra
composite volcano: steep-sided volcano formed from alternative layers of violent
eruptions of tephra and quieter eruptions of lava
Pg. 226
asthenosphere: plastic-like layer of the mantle under the lithosphere
rift: long crack, fissure, or trough that forms between tectonic plates moving apart
at plate boundaries
hot spot: hot, molten rock material that has been forced upward from deep inside
Earth, which may cause magma to break through Earth’s mantle and crust and may
form volcanoes