Questions and Answers
What is the study of earthquakes called?
What is deformation?
The bending, tilting, and breaking of earth's crust; the change in the shape of rock in response to stress.
What is elastic rebound?
The sudden return of its elastically deformed rock to its undeformed shape.
What are seismic waves?
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What are P waves?
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What are S waves?
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Name the 3 plate boundaries and their corresponding major fault type: Transform= ______, Convergent= ______, Divergent= ______.
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What is the difference between a seismograph and a seismogram?
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What is an epicenter?
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What is the focus of an earthquake?
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Identify the 3 steps to finding an earthquake's epicenter: A circle is drawn around a seismograph station. When a second circle is drawn around another seismograph station, the circle overlaps the first circle in ______. When a circle is drawn around a third seismograph station, all three circles intersect in one spot - the earthquake's epicenter.
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Who created the Richter Scale and what does it measure?
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What are the effects of different sized earthquakes?
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Define magnitude.
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How are magnitude and ground motion related to the Richter Scale?
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What is the Modified Mercalli Scale?
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What does the intensity of an earthquake measure?
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Why is a 6.0 magnitude earthquake so much more destructive than a 5.0 magnitude earthquake?
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Why is a large earthquake often followed by numerous aftershocks?
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What is the Worldwide Earthquake Frequency for 2.0-2.9 magnitude earthquakes?
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Study Notes
Seismology and Earthquake Fundamentals
- Seismology is the study of earthquakes and seismic waves.
- Deformation refers to the bending, tilting, and breaking of earth's crust, indicating stress on rocks.
- The concept of elastic rebound describes how deformed rocks snap back to their original shape after an earthquake.
Seismic Waves
- Seismic waves are energy waves that radiate from an earthquake's focus in all directions.
- P waves (primary waves) move rock particles in a back-and-forth direction.
- S waves (secondary waves) cause rock particles to move side-to-side.
Plate Boundaries and Fault Types
- Three primary plate boundaries exist, each associated with specific fault types:
- Transform boundaries are characterized by strike-slip faults.
- Convergent boundaries involve reverse faults.
- Divergent boundaries feature normal faults.
Earthquake Detection and Analysis
- Seismographs are instruments that record seismic waves, while seismograms are the resulting visual representations of earthquake motion.
- The epicenter is located directly above an earthquake's focus on the earth's surface, where initial motion occurs.
Locating an Earthquake's Epicenter
- To identify an earthquake's epicenter, circles are drawn around seismograph stations based on data, and their intersections reveal the epicenter.
Measuring Earthquake Magnitude and Intensity
- The Richter Scale, developed by Charles Francis Richter, measures ground motion to determine earthquake strength.
- Magnitude reflects the size or extent of earthquakes, while intensity measures damage severity.
- The Modified Mercalli Scale is utilized to assess earthquake intensity.
Effects of Earthquake Size
- Earthquakes registered with a magnitude of 2.0 can only be detected by instruments, while those at 3.0 are recognizable by people at the epicenter.
- Magnitudes of 4.0 and 5.0 are felt more broadly and can cause local damage, with significant destruction occurring at 6.0 and above.
Earthquake Aftershocks and Frequency
- Aftershocks occur following large earthquakes due to the readjustment of forces along the fault, possibly lasting for extended periods.
- The worldwide earthquake frequency includes vast numbers of smaller quakes, drastically decreasing in frequency as magnitude increases:
- Approximately 365,000 earthquakes are recorded at magnitudes between 2.0-2.9.
- The number of earthquakes drops to just 1 for those measuring 8.0 or higher.
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Description
Test your knowledge of key terms related to earthquakes with this flashcard quiz. Learn about seismology, deformation, elastic rebound, and seismic waves. Perfect for students or anyone interested in geology!
