SHAKING AND QUAKING, MONITORING EARTHQUAKES
Geologists monitor earthquakes to better understand how the crust is affected by movements and to determine how plates are moving. The following activity explains this study, seismology, and how to monitor crustal movement by having students create their own seismograph.
Instructional Method: Activity
Goal: Explain how scientists monitor earthquakes.
Objectives: Students will be able to:
Activity time: 30 minutes
Seismic waves are energy waves produced when friction along a fault causes vibrations in the crust. As energy waves pass through the crust they can be monitored by sensitive devices called seismographs. When evaluating collected data, various scales are used to describe the magnitude of fault movement, inferred from the intensity of the waves.
The magnitude of seismic waves are evaluated according to a Richter scale. This scale is a mathematical computation of the size of the earthquake. Seismographs record zigzag traces showing ground movement beneath the instrument. Sensitive seismographs, which greatly magnify these ground motions, can detect strong earthquakes from sources anywhere in the world.
Monitoring earthquakes, all over the world, allows scientists to determine where the earthquake originated. In addition to recording ground motion, seismographs also record the date and time the seismograph felt the waves. Using multiple recordings, scientists are able to calculate where the earthquake originated. The origin of an earthquake is called its hypocenter. This is the point beneath Earth's surface where fault rupture (movement) occurred. The point on the surface that is directly above the hypocenter is called the epicenter.
The following information gives an idea of the characteristics and occurrences of various magnitudes of earthquakes around the world. In the side column there are links that help in further studies of earthquakes.
The following activity explains how to create your own seismograph. It my not record small earthquakes but can be used to show how it is done in reality. To learn more about seismic waves look at "Surfing Rock Waves".
How do geologists know earthquakes are happening even if they can not feel them? Why is it important to monitor earthquakes? Can anyone predict earthquakes? Have you ever felt an earthquake? Did you know how far away it was? How did geologists determine its location, epicenter and hypocenter?
Included National Parks and other sites:
Aniakchak National Monument and Preserve
Utah Science Core:
5th Grade Standard 2 Objective 1,2,3
Last updated: February 24, 2015