Chapter 9 Flashcards
Earthquake
Are the vibrations in the ground that result fro, movement along breaks in the Earth’s lithosphere.
Fault
Is the break in Earth’s lithosphere where one block of rock moves toward, away from, or past another.
Seismic waves
Energy that travels as vibrations on Earth
Focus
Waves originate where rocks first move along the fault, at a location inside the Earth.
Epicenter
The location on Earth’s surface directly above the earthquakes focus.
Primary wave
Also called P-waves, cause particles in the ground to move in a push-pull motion similar to a coiled spring.
Secondary wave
Also called S-waves are slower than P-waves. They cause particles to move up and down at right angles relative to the direction the wave travels.
Surface waves
Cause particles in the ground to move up and down in a rolling motion.
Seismologists
Scientists that study earthquakes
Seismoter
Measures and records ground motion and can be used to determine the distance seismic waves travel.
Seismogram
A graphical illustration of seismic waves
Volcano
A vent in the Earth’s crust through which melted- or molten rock flows.
Magma
Molten rock below Earth’s surface.
Lava
Molten rock erupts onto Earth’s surface.
Hot spot
Volcanoes that are not associated with plate boundaries
