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?
Signup and view all the answers
What are P waves?
Signup and view all the answers
What are S waves?
Signup and view all the answers
Name the 3 plate boundaries and their corresponding major fault type: Transform= ______, Convergent= ______, Divergent= ______.
Signup and view all the answers
What is the difference between a seismograph and a seismogram?
Signup and view all the answers
What is an epicenter?
Signup and view all the answers
What is the focus of an earthquake?
Signup and view all the answers
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.
Signup and view all the answers
Who created the Richter Scale and what does it measure?
Signup and view all the answers
What are the effects of different sized earthquakes?
Signup and view all the answers
Define magnitude.
Signup and view all the answers
How are magnitude and ground motion related to the Richter Scale?
Signup and view all the answers
What is the Modified Mercalli Scale?
Signup and view all the answers
What does the intensity of an earthquake measure?
Signup and view all the answers
Why is a 6.0 magnitude earthquake so much more destructive than a 5.0 magnitude earthquake?
Signup and view all the answers
Why is a large earthquake often followed by numerous aftershocks?
Signup and view all the answers
What is the Worldwide Earthquake Frequency for 2.0-2.9 magnitude earthquakes?
Signup and view all the answers
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.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
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!