Chapter 7 Review Sheet
You are to answer the following questions. You should be able to use the pages I give as answers to answer the question in full sentences not phrase. On your test there will be 8 or 9 questions you will have to attempt. Now you have to prepare the following questions as you will not know which ones I will give in the test. For some questions below I gave page numbers and for some I gave the answers. For a few I even mentioned what I expect to see in the answer. Read through each questions and its answer carefully. It is the first test of 3rd Marking Period. Make it worth it! Good Luck!
1. What is an earthquake?
Earthquakes are vibrations caused by breaking and moving of rocks.
2. Explain the theory of elastic rebound?
Rocks pull and push each other with forces if enough force is applied, rocks change shape.
This can cause them to break and the broken ends may snap back. This snapping back is called elastic rebound.
3. Define faults and discuss the types.
Read page 179 to define fault. Name the three types of faults and discuss them.
Look at the images on that page for points about each.
4. What are seismic waves? And who are seismologist?
Earthquake waves are seismic waves. Seismologists are scientists who study earthquakes and seismic waves.
5. Where is the focus of an earthquake located?
The focus of an earthquake is located inside the earth where movement first occurs and an energy is released.
6. What are seismographs? Describe one type of seismograph.
Read page 181 " Earthquake measurements. The last paragraph on the page discusses the structure of one type of seismograph.
7. Describe the three types of seismic waves. You are to draw a t-chart comparing and contrasting all three.
Read page 181 "seismic waves".
1) Surface waves are the slowest and the largest of the seismic waves. They cause the most destruction. They move along the surface of the Earth. Some for them vibrate in a side-to-side, or swaying, motion parallel to Earth's surface. This motion can be particularly devastating to human-built structures.
2) Primary waves travel through Earth's interior. They are also known as P-waves. They travel fastest through rock material by causing particles in the rock to move back and forth, or vibrate, in the same direction as the waves are moving.
3) Secondary waves are known as S-waves. They too like P-waves pass through Earth's interior. These waves move through rock material by causing particles to vibrate at right angles to the direction in which the waves are moving.

8. What is Richter scale?
Richter magnitude is based on measurements of amplitudes, or heights, of seismic waves as recorded on seismographs. Richter magnitude describes how much energy an earthquake releases. For each increase of 1.0 on the Richter Scale, the amplitude of the highest recorded seismic wave increase by 10.
9. What do you mean by Seismic safe? Describe some structures that are seismic safe.
Seismic Safe are the ability of structures t stand up against the vibration caused by earthquake. Many high-rise buildings stand on huge steel-and-rubber supports that ride out the vibrations of an earthquake. Underground water and gas pipes are replaced with pipes that will bend during an earthquake. Highways have cement pillars with spiral reinforcing rods.
10. Define focus and epicenter. Draw an outline to explain the location of both. pg. 180. Look at notes for the easier version I drew on the board.
11. What determines how a volcano erupts?
Look at notes. pg. 189
12. Compare Shield volcanoes and Composite Volcanoes.
Look at notes. pg. 190 and 191. Definition and one example is required. If you do not have your notes get the from somebody.
13. Why is silica-rich magma explosive?
Silica-rich magma is sticky and thick. It tends to hold gases that cause pressure to build until finally the volcano erupts explosively.
14. What is a hot spot?
Hot spots are bodies of magma forced upward through Earth's mantle and crust that are not necessarily part of a plate boundary. pg. 196
15. In which boundary do rifts form? Why are rifts important?
pg. 195 Rifts are long cracks, fissure, or trough that forms between tectonic plates moving apart at plate boundaries. They are important as they act as passageways for magma originating in the mantle. They provide zones for lave to flow onto Earth's surface. Fissure eruptions occur along these rift zones.