Active or Not? That Is The Question


To evaluate seismic activity along major San Francisco faults.


  • 1999 Landsat 7 image of the San Francisco Bay area
  • fault map of the San Francisco Bay area

The Story

There are faults in the San Francisco Bay Area. Some of them are active but some are not.

1999 Landsat 7 Image - San Francisco Bay

1999 Landsat 7 Image of the San Francisco Bay Region.
Image Processing by Janet Chien NASA/GSFC

You and a colleague have been hired by a local land developer to help select land where new apartments can be built. The developer wants the land to be as close to downtown as possible, but far away from active faults. (Being close to a fault is okay as long as it's not an active fault.)


For this work you have selected a recent image from Landsat 7, and you have added a yellow mark to show the center of each seismic event that has occurred during the past 100 years. You have also found a good map of the faults in the area.

Satellite Data and Fault Map

Compare the satellite image with the fault map. Look for faults that seem the most active.


Print out the fault map and use it to mark the spot where you recommend placing the new apartments. Write a short paragraph in which you explain your selection.


Copyright 1999-2007 Event-Based Science Project