It seems like the southern states have been getting their fair share of seismic activity lately. Increase your knowledge of earthquakes by taking this quiz.
1. Where and when was the first earthquake recorded? Hawaii, Sri Lanka, Alaska, Chili.
2. Which state in the United States has the most earthquakes? California, Alaska, Washington, Hawaii.
3. Which continent has the fewest earthquakes? Antarctica, Australia, North America, Europe.
4. Each state in the United States has an earthquake history. What was the largest magnitude of an earthquake in your state? 7.7, 8.0, 6.5, 5.0, none of the above.
5. Earthquakes occur when rocks ___. Bend; Break; Compress; Stretch.
6. Rocks can break when the ____ is exceeded. Elastic deformation, elastic limit, fault line, plate boundary.
7. _____ are formed by forces of tension. Reverse, Strike-slip, Compression, Normal.
8. One rock surface hanging over an adjacent rock surface might indicate that ____ fault action has occurred. Normal, strike-slip, compression, reverse.
9. Which type of seismic wave travels the fastest? Primary, Tsunami, Secondary, surface.
10. Mountains are formed on the _____. upper mantle, inner core, outer core, crust.
ANSWERS
1. The largest recorded earthquake in the world was a magnitude 9.5 in Chile on May 22, 1960.
2. Alaska accounts for more than 50 percent of all U.S. earthquakes, with 12,053 reported between 1974-2003. The interior of Antarctica has “icequakes,” which, although they are much smaller, are perhaps more frequent than earthquakes in Antarctica. The icequakes are similar to earthquakes, but occur within the ice sheet itself instead of the land underneath the ice. Florida and North Dakota have the smallest number of earthquakes in the United States.
3. Antarctica.
4. The first principal earthquake, M7.7, occurred at about 2:15 a.m. (local time) in northeast Arkansas on December 16, 1811. The second principal shock, M7.5, occurred in Missouri on January 23, 1812, and the third, M7.7, on February 7, 1812, along the Reelfoot fault in Missouri and Tennessee.
5. Break. As rocks move and break, energy is released in the form of an earthquake.
6. Elastic limit. Rocks are able to bend somewhat, but when the elastic limit is exceeded, the rocks will break.
7. Normal. As rocks are pulled apart by the force of tension, normal faults occur.
8. Reverse fault action. When rocks are compressed together, one rock surface will often hang over the adjacent rock surface. This is the result of reverse fault action.
9. Primary waves travel the fastest, especially through solids.
10. Mountains are formed on the Earth’s surface, or the crust.