Slide 7 of 24
PROXIMITY TO FAULT
- Earthquakes release energy along the entire portion of the ruptured fault surface.
- The distance between the building and the fault source is more important than the distance to the epicenter.
- The Index Map shows the active fault zones in California.
- The 1997 Uniform Building Code uses this information to determine when earthquake forces on buildings must be increased due to fault proximity.
- Main points:
- The amount of damage to a house depends on how big the earthquake is.
- The amount of damage depends on how near the house is to the epicenter of the quake
- Earthquake forces can increase up to 100 per cent for buildings near large faults.
- Just because a house is not damaged in a quake does NOT mean that it is earthquake-proof: it may instead have been far enough away from the epicenter to prevent earthquake damage.