Project Choosing

Experiment:

Time Required	Long (2-4 weeks)
Prerequisites	This project uses the Global Earthquake Explorer program to download and analyze data from a global seismic network. In order to do this project you will need to be comfortable installing and working with a new program on your computer. This project requires a computer with high speed Internet access. You will also need to understand some basic trigonometry. You should be comfortable with determining the lengths of the sides of right triangles when given an angle and the length of one side. Experience looking at seismograms is useful but not required.
Material Availability	Readily available
Cost	Very Low (under $20)
Safety	No issues

Abstract

When an earthquake occurs, seismic shock waves travel out through the earth from the source of the event. The shock waves travel through the earth or along the Earth's surface, and can be recorded at remote monitoring stations. Some of the waves that travel through the earth are blocked or refracted by the Earth's liquid core, which means that monitoring stations located certain distances from the earthquake do not detect these waves. This creates a "seismic shadow" that you can use to estimate the diameter of the Earth's core. This geology science project shows you how.

Objective

Estimate the diameter of the Earth's core by measuring seismic waves around the globe.

Independent Variables

• The location of the seismographs.

  

Dependant Variables

• The result of the seismograph.

Constants

• The time taken to take the data

• The type of seismic waves travels from the core upon each earthquake's occurrence

• The diameter of the Earth's core  

• The seismic shadow from the data, used to calculate the diameter of the Earth's core.

Hypothesis

If the location of the seismographs are placed correctly and with a proper method, the result of the seismograph would enable to tell us the diameter of the Earth's core.