Cross Curricular Graphing Activity

Graphing is one math skill that everyone in junior or senior high needs to master. Throughout life we are confronted by graphs and tables.  Knowing how to create and interpret them is as much a life skill as adding or subtracting.  Rather than just giving students a data table and having them plot data I've developed a great demonstration using a spreadsheet and the Earthquake data from the United States Geological Survey.


Go to the USGS Past Earthquake Archive (http://earthquake.usgs.gov/earthquakes/eqarchives/epic/). At the bottom of the page you'll see something like this:

To restrict the data change the right longitude to -40 and change the start date to one month before today.  When you press search all the Earthquakes around the world for the last month will be displaced in columns that look like this:

There is lots of information in this table and you could probably make several lessons on geology just on this.  However all we're interested in is the latitude and longitude.  To get that data we have to select all the other columns though.  Click near the first date and select several thousand entries by dragging the mouse down the page. Once you think you've got enough entries selected, right click and press copy.  

Open a spreadsheet (I'm using Excel) and right click again. Click on paste special and click on text.  This will put all the numbers in different cells in the spreadsheet.  Then you can delete all the columns expect the Latitude and Longitude ones.

Once you've deleted the extra data you should have columns that look like this (except with several thousand more entries):

Since longitude will be the x-coordinate and latitude will be the y-coordinate we need to flip the order of the columns. This is fairly simple to do with a copy/paste command.

Delete the 'Log' and 'Lat' labels and select both lists then click on insert and scatter chart. Once the chart is inserted it will look something like this:

We can make the data a bit easier to visualize by changing the scales. Since the north and south poles are located at latitudes of +90 and -90 click on the y-axis and change the maximum/minimum values to those.  This will change the graph to this:

Because we limited the data set from longitudes of -180 to -40 double click on the x-axis and and enter those as the maximum and minimum x-values.  If you like, you can also decrease the size of each point. Adding a title for the graph and labeling the x- and y- axis you'll get the graph 

Can you see the outline of the North and South American continents?  This graph also shows Hawaii as well as the boundaries of the Nazca plate.  Compare that with a map showing the tectonic plates around the ring of fire:

Not only does this provide the opportunity to talk about graphing techniques but it highlights the usefulness of graphing and can even lead into discussions of geology and seismology. What other examples of graphing in cross curricular activities have you used?