Faults and Stress
This term refers to the sudden, violent release of energy in Earth's interior, which is similar to the experience of a stuck door finally flying open.
What is an earthquake?
These are the waves of energy produced by an earthquake that travel through Earth.
What are seismic waves?
This instrument is used to detect and record the seismic waves of an earthquake.
What is a seismograph (or seismometer)?
This massive ocean wave can be triggered by underwater earthquakes, such as the famous 2004 event covered in the chapter connection.
What is a tsunami?
Unlike the Richter scale which measures energy, this modern scale is preferred by seismologists today because it accurately measures total energy released by very large earthquakes using fault surface area and slip.
What is the Moment Magnitude Scale?
Friction between two objects prevents them from moving at first, causing this to build up until a break occurs.
What is stress (or friction/energy)?
ection 9.2 compares these fast-moving waves to race cars.
What are seismic waves?
This well-known scale measures the magnitude (size/energy) of an earthquake.
What is the Richter scale? (Section 9.3)
The Chapter 9 connection focuses on the devastating earthquake and tsunami that occurred in this ocean in 2004.
What is the Indian Ocean?
This instrument—a modern upgrade from ancient Chinese inventions—is bolted to bedrock so it can move precisely with the ground during an earthquake.
What is a seismograph (or seismometer)?
As you learned in Chapter 8 and Chapter 9, Earth's outer shell (the lithosphere) is broken up into these moving pieces.
What are lithospheric plates (or tectonic plates)?
This is the primary type of seismic wave that travels the fastest and arrives first at a seismograph station.
What are primary waves (P-waves)?
Each whole number increase on the Richter scale represents roughly this amount of increase in the energy released by an earthquake.
What is about 10 times more energy
This term describes the underground origin point where the rock actually breaks and slips during an earthquake.
What is the focus (or hypocenter)?
This specific boundary type—famous for features like the San Andreas Fault—involves tectonic plates sliding horizontally past one another rather than colliding or pulling apart.
What is a transform fault boundary
According to the textbook introduction for Chapter 9, what is the quickest and easiest way to find plate boundaries?
What is plotting earthquakes on a map?
This secondary type of seismic wave arrives after P-waves and moves rock particles side to side
What are secondary waves (S-waves)
This scale measures the intensity of an earthquake based on the actual damage observed and felt by people, rather than just instrument readings.
What is the Modified Mercalli Intensity Scale? (
When seismic energy travels through loose, water-saturated soil, it can cause the ground to temporarily behave like a liquid in a process known by this term.
What is liquefaction?
While the Richter scale measures magnitude, this modern scale is preferred by seismologists today because it calculates total energy released using the fault's surface area and slip.
What is the Moment Magnitude Scale
This is the specific type of force that opposes the motion between two stuck rock surfaces along a fault before it suddenly gives way.
What is friction?
These seismic waves travel along Earth's surface and often cause the most severe ground damage during an earthquake.
What are surface waves?
This is the point on Earth's surface directly above where an earthquake actually originates underground.
What is the epicenter?
This is the primary geological cause of most major earthquakes worldwide, involving the interaction of moving lithospheric plates.
What is plate tectonics (movement along plate boundaries/faults)?
This type of fault is formed when tectonic forces pull rock apart by tension, causing the hanging wall to drop down relative to the footwall.
What is a normal fault?