Name: ___________________________ Date: _____________ Class:_________ Hour:_______
Chapter 5 Earthquakes Guided Notes
Section 1
What Are Earthquakes?
Write your answer in your science journal.
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Explain where earthquakes take place.
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Explain what causes earthquakes.
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Identify three different types of faults that occur at plate boundaries.
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Describe how energy from earthquakes travels through the Earth.
Where Do Earthquakes Occur?
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__________________ Most earthquakes take place near the edges of tectonic plates.
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Faults As a result of ______________________________, numerous features called
faults exist in the Earth’s crust. A fault is a break in the Earth’s crust along which blocks
of the crust slide relative to one another. Earthquakes occur along faults because of this
sliding.
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__________________ Elastic deformation leads to earthquakes.
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__________________ The sudden return of elastically deformed rock to its original
shape is called elastic rebound. Elastic rebound is illustrated on the next slide.
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__________________ Waves that travel through solids, liquids, and gases are called P
waves (pressure waves).
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__________________ After being deformed from side to side, the rock springs back to
its original position and S waves are created. S waves, or shear waves, are the secondfastest seismic waves.
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__________________ move along the Earth’s surface and produce motion mostly in the
upper few kilometers of Earth’s surface.
Section 2
Earthquake Measurement
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Explain how earthquakes are detected.
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Describe how to locate an earthquake’s epicenter.
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Explain how the strength of an earthquake is measured.
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Explain how the intensity of an earthquake is measured
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Locating Earthquakes
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Determining Time and Location of Earthquakes Seismologists use seismograms to
calculate when an earthquake began. Seismologists also use __________________ to
find an earthquake’s __________________.
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The __________________ Perhaps the simplest method by which seismologists find an
earthquake’s epicenter is the S-P time method. The next slide illustrates how the S-P
time method can be used to find an earthquake’s epicenter.
Measuring Earthquake Strength and Intensity
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The Richter Magnitude Scale Throughout much of the 20th century, seismologists used
the ___________________________, commonly called the Richter scale, to measure
the strength of earthquakes.
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Earthquake Ground Motion The Richter scale measures the __________________
from an earthquake and adjusts for distance to find its strength.
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Modified Mercalli Intensity Scale Currently, seismologists in the United States use the
___________________________________________ to measure earthquake intensity.
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Section 3
Objectives
Earthquakes and Society
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Explain how earthquake-hazard level is determined.
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Compare methods of earthquake forecasting.
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Describe five ways to safeguard buildings against earthquakes.
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Outline earthquake safety procedures.
Earthquake Hazard
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What Is Earthquake Hazard? Earthquake hazard is a measurement of how likely an area
is to have _______________________________ in the future.
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Area with a High Hazard The West Coast of the United States has a very high
_____________________________________ because it has a lot of seismic activity.
Earthquake Forecasting
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______________________________ The strength of earthquakes is related to how
often they occur.
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The Gap Hypothesis The gap hypothesis is a hypothesis that states that sections of
active __________________ that have had relatively few __________________ are
likely to be the sites of strong earthquakes in the future.
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Using the Gap Hypothesis Some seismologists think the
__________________________ helped forecast the approximate location and strength
of the 1989 Loma Prieta earthquake.
Earthquakes and Buildings
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Retrofitting The process of making older structures more earthquake resistant is called
__________________.
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Earthquake Resistant Buildings Architects and engineers use the newest technology to
design and construct buildings and bridges to better withstand __________________.
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Are You Prepared for an Earthquake?
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Before the Shaking Starts The first thing you should do is safeguard your home against
__________________. Next, you should find safe places within each room of your home
and outside of your home.
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When the Shaking _________ The best thing to do if you are indoors when an
earthquake begins is to crouch or lie face down under a table or desk in the center of a
room.
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After the Shaking_________Remove yourself from immediate danger, such as downed
power lines and broken glass. Be aware that there may be __________________.
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Concept Map
Use the following terms to complete the concept map on the next slide: seismograph,
seismic waves, earthquakes, surface waves, body waves, S waves.
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