Chapter 6 2.0 Flashcards
A stressed crack in a rock
Joint
A crack or joint in a rock
Fault
The first earthquake to reach a seismic station
P waves
The second earthquake wave to reach a seismic station
S waves
One of many earthquake waves to travel along the crust
Surface waves
Detects earthquake waves
Seismometers
The actual center of an earthquake activity
Focus (hypocenter)
The point where an earthquake actually occurs
Epicenter
The size or intensity of some measurable quantity
Magnitude
A system that reports the magnitude or energy of an earthquake
Richter scale
A measure of the concentration of energy expanded or the effects of energy released
Intensity
An Italian volcanologist and director of the Vesuvius observatory
Mercalli
A far-reaching, devastating water wave caused by seismic activity
Tsunamis
Includes seismometers and a way to record or graph the changing earth waves
Seismograph
Rapid mass wasting of earth materials downhill
Landslides
Oil, grease, and other substances used to reduce friction
Lubricant
Secondary earthquakes
Aftershocks
Any force exerted on the matter in an object
Stress
Forces/stresses that act to squeeze or crush an object or substance
Compression stress
Forces/dresses that act to pull an object or substance apart
Tension stress
Forces/stresses that act in opposite directions in different parts of the same object or substance
Shear stress
The amount of strain a material can endure
Ductility
A push or pull on an object
Force
Any change in the shape of a solid due to stress is exerted on the material
Strain
The compass direction of an imaginary line drawn across a fault face or rock
Strike
The angle of slope of a fault face or stratum
Dip
A fault whose main motion is parallel to its tip direction
Dip-slip fault
Where are earthquakes the strongest?
Focus
List three places seismic waves carry energy
• away from the focus
• through earth’s interior
• across the surface
List three things that are measured on earthquake scales
•magnitude
•seismic waves
•seismometers
What does tenfold on the Richter scale mean?
Ranges from one to 10
