Map Your Earthquakes

Topic:
Earth science

Type of Web activity:
Create map of local earthquakes.

Materials / Software needed:
Web browser

Grade Level:
9-12

Time involved:
One class period

Created:
July 2000

This site developed and maintained by Deborah Hunt and Eric Muller .

3601 Lyon St.
San Francisco, CA 94123

©2000 The Exploratorium

You'll need your geographic coordinates. If you don't know your latitude and longitude, start with the Coordinates Lesson and then return here.

As an example, lets start with my coordinates at the Exploratorium. 37N 48' 10" and 122W 26' 54"

First I need to convert these coordinates to decimal degrees.
There are 60 seconds in a minute, so the seconds can be incorporated into the minutes this way:

Latitude = 37N 48+10/60" = 37N 48.17
Longitude = 122W 26+54/60" = 122W 26.9"

There are 60 minutes in a degree, so we can incorporate the minutes into the degrees this way:

Latitude = 37+48.17/60 = 37.80N
Longitude = 122+26.9/60 = 122.45W

Make this calculation on your coordinates now.

Search for nearby earthquakes. The Incorporated Research Institutions for Seismology (IRIS) has a site on which one can search for earthquakes within a specified region. Make up a 1 degree by one degree boundary centered on the location you found above. My limits are:

North: 38.3

West: -123 East: -122

South: 37.3

Set the starting date/time to: 1964 01 01 000000, which is the start of the data base.

Set the minimum magnitude to 0, so that all earthquakes will be included.

Here are the results of my search. Is your area this active?

Which faults? There is a USGS site for plotting the faults of the western US. If you live in this area, go there now. Then click on "Go to #1 Fault map." Click on the + magnifying glass symbol at the top of the map and then draw a box around your area. Repeat this process until you have a map of about the same region as your seismicity map. Here is what my map looked like.