Name Earthquakes and Volcanoes What causes earthquakes and volcanic eruptions? Before You Read Before you read the chapter, think about what you know about earthquakes and volcanoes. In the first column, write three things you already know about these natural events. In the second column, record three things that you would like to learn more about. When you have completed the chapter, think about what you have learned and complete the What I Learned column. Date K What I Know W What I Want to Learn L What I Learned Chapter Vocabulary Lesson 1 Lesson 2 NEW earthquake fault seismic wave focus epicenter primary wave secondary wave surface wave seismologist seismometer seismogram REVIEW plate boundary convergent NEW volcano magma lava hot spot shield volcano composite volcano cinder cone volcanic ash viscosity ACADEMIC dissolve Earthquakes and Volcanoes 151
Lesson 1 Earthquakes Scan Lesson 1. In your Science Journal, write three questions that you have about earthquakes. Try to answer your questions as you read. What are earthquakes? Define earthquakes. Where do earthquakes occur? Summarize the distribution of earthquakes on Earth. Categorize information about the relationship between earthquake e vents and plate. Boundary Type Convergent Depth of Earthquake Other Details Divergent Convergent involving two continents Illustrate rock deformation, and write a short description of how this process works. Drawing 152 Earthquakes and Volcanoes
Describe each type of fau lt. Type of Fault Location Strike-slip Normal Reverse Distinguish between an earthquake s focus and its epicenter. Seismic Waves Compare the 3 types of seismic. Provide at le ast three details about each type. Type of Fault Primary (P-) Secondary (S-) Surface Earthquakes and Volcanoes 153
Mapping Earth s Interior Identify what scientists have discovered about Earth s interior by studying seismic. Inner and outer core: Mantle: Distinguish between a seismometer and a seismogram. Seismometer Seismogram Sequence the steps followed i n locating an earthquake s epicen ter. Find the arrival time difference. Determine the between the appearance of the first and the first on the seismogram. Find the distance to the epicenter. Use a to determine. Find the time difference on the. Read the distance from the epicenter on the. Plot the distance on the map. Draw a around the seismometer location so that all points are the same distance from the station determined in Step 2. Repeat these steps for at least more seismometer locations. The epicenter is. 154 Earthquakes and Volcanoes
Determining Earthquake Magnitude Compare and contrast the Richter magnitude scale, the moment magnitude scale, and the Modified Mercalli scale. Richter Magnitude Scale The scale uses the amount of at a given from an earthquake to determine. All Measure the size, or intensity, of an earthquake Moment Magnitude Scale Measures the Modified Mercalli Scale Measures the released by an earthquake; energy released depends on: 1. t he size of the ; results from Determined based on that 2. the that occurs; 3. the of the rocks. Scale ranges from Record four indicators that seismologists use to determine earthquake risk. 1. 2. 3. 4. Explain why two different earthq uakes with the same Richter magnitude scale readings could have very different Modified Mercalli scale numbers. to Earthquakes and Volcanoes 155