Chapter 19 Vocab - Forces inside EARTH Flashcards
The total force acting of crustal rocks per unit area
Stress
The deformation of materials in response to stress
Strain
Causes materials to bend and stretch, proportional to stress
Elastic Deformation
Permanent deformation caused by stain when stress exceeds a certain value
Plastic Deformation
Fracture or system of of fracture in Earth’s crust that occurs when stress is applied too quickly or stress is too great
Fault
The vibrations of the ground produced during an earthquake
Seismic Wave
Seismic wave that squeezes and pushes rocks in the same direction the wave travels
Primary Wave (P-wave)
Seismic wave that causes rock particles to move at right angles to the direction of the wave
Secondary Wave (S-wave)
Point of initial fault rupture where an earthquake originates
Focus
Point on earth’s surface directly above the focus of an earthquake
Epicenter
Instrument used to measure horizontal or vertical motion during an earthquake
Seismometer
Record produced by a seismometer that can provide individual tracking of each type of seismic wave
Seismogram
Measure of energy released during an earthquake
Magnitude
Numerical rating system used to measure the amount of energy released during an earthquake
Richter Scale
The size of seismic waves
Amplitude
Scale used to measure earthquake magnitude using values that can be estimated from the size of several types of seismic waves
Moment Magnitude scale
Measures earthquake intensity from I to XII
Modified Mercalli Scale
The amount of damage caused by an earthquake
Intensity
Large powerful ocean wave generated by the vertical motions of the seafloor during an earthquake
Tsunami
Place along an active fault that has not experienced an earthquake for a long time
Seismic Gaps
