A Science Fair Project on a Seismic Wave for Kids

Overview

• In this project from the Web site Science Buddies, kids use online earthquake data to create their own seismograms. The purpose of the project is to find out the velocities, or speeds, of different seismic waves. By comparing the velocities, young scientists can find out whether seismic waves always travel at the same speed or whether their speed varies, as well as whether the wave's speed is affected by the initial force of the earthquake.

Getting the Data

• To give yourself data to work with, assemble a list of historic earthquakes. Make sure to note the time and date when each one occurred, as well as its location and depth relative to the earth's surface. The most important information to collect is the latitude and longitude of each earthquake, since these will help you calculate the velocity. To limit additional factors and make your comparison easier, look for earthquakes from roughly the same part of the world.

Making a Seismogram

• When making your seismogram, select the desired time period for observing seismic wave activity. It is best to set a wide enough time period that you will be able to see seismic data for both before and after the time of the earthquake. Produce a visual seismogram, a graph where the y-axis shows the intensity of ground motion and the x-axis represents time. Ground motion intensity, represented by squiggles, should increase when seismic waves are traveling as a result of the earthquake.

Calculating Seismic Wave Velocity

• When you know the latitude and longitude of the epicenter of each earthquake, as well as the latitude and longitude of the seismometer station that recorded it, you will be able to calculate the distance between these points. Divide this distance by the elapsed time you chose earlier. Using the basic physics formula "velocity = distance / time," you now have the velocity for the seismic waves in each earthquake. Now you can use the velocities to answer questions about whether different conditions affect the speed of seismic waves. Print out your results and display them on posterboard at the science fair.