Inquiry:  What can earthquake data suggest about the interior workings of the earth?

Materials:  graph paper, pencil

Vocabulary: 

    a) focus or hypocenter - the point INSIDE the earth where rock breaks (the source of an earthquake)

    b) epicenter - the point ON the surface of the earth directly ABOVE the epicenter

Directions:

    1) Carefully consider the seismic data gathered in a coastal region.

    2) Graph the data, and label each seismic event with its letter.

Remember:

• When constructing a graph, use equal increments on an axis.

• Consider what your value range is when deciding what those increments should be.

• A graph that isn't properly labeled is useless to the reader.

Analysis Questions:  Copy and answer these questions.  You must have your graph completed in order to analyze the data.  You will submit portions of your analysis in electronic format later.

1. Did all of the earthquakes occur within the same layer of the earth's interior?  Explain.

2. Did all of the earthquakes occur the same distance from the coast?

3. What point (coordinate) on your graph represents the actual coastline?

4. What relationship do you see between depth of the foci and distance from the coast?

5. Why do none of the earthquakes occur at a depth with a positive integer?

6. What internal process might be responsible for the data illustrated in your graph?  EXPLAIN what the pattern is showing.  (EXPLAIN your thinking.)

Data: