1. Lessons 3-5 Notes

2. Lesson 3 “Recording Earthquake Waves” Vibrations from an earthquake can be recorded with a seismograph; a seismogram is a recording made by a seismograph. – In the seismograph lab, the harder we hit the table, the larger the waves were on the seismogram. The larger the earthquake  larger waves on seismogram. The direction of the vibrations also affected the seismogram. This is why seismologists need recordings from several seismographs so that they can get an accurate reading.

3. Focus vs. Epicenter The smaller wave on a seismogram is a P- wave. The focus of an earthquake is the place where the rupture begins and energy is released. The place on the earth’s surface directly above the focus is the epicenter.

4. Seismograms Seismologists use seismograph stations from multiple locations. The location with the smallest amount of lag time between the P and S wave is the one that is closest to the epicenter of the earthquake. The time between each earthquake wave arrived at each city are different because they are different distances away from the epicenter.

5. Lesson 4 “Plotting Earthquakes” Earthquakes and volcanoes occur in many of the same specific locations that are on plate boundaries. The Ring of Fire, the Mid-Atlantic Ridge, and Mediterranean-Himalayan Belt are areas of intense earthquake activity. – Ring of Fire: around edges of Pacific Ocean – Mid-Atlantic Ridge: runs down the middle of the Atlantic Ocean floor – Mediterranean-Himalayan Belt: extends from west Indonesia through the Himalayas in Asia and the Mediterranean region.

6. Intensity vs. Magnitude Intensity is the measure of damage done by an earthquake and magnitude is the measure of the total amount of energy released at the focus of an earthquake.

7. Lesson 5 “Using Earthquakes to Study the Earth’s Interior” Crust: Lithosphere Mantle: asthenosphere directly below lithosphere Outer Core: Liquid Inner Core: Solid

8. Lithosphere vs. Asthenosphere Lithosphere – solid outer shell of earth that is broken up into segments. Asthenosphere – directly below lithosphere and flows like taffy.

9. How seismologists use earthquakes to study the earth’s interior: Earthquake waves travel through some substances, but not others, and travel at different speeds depending on the substance. Patterns of earthquakes and their waves provide information about plate boundaries and the interior structure of the earth.