M A S T E R P A G E
Soil and Geologic Maps
and Map Sources
2.5b
Q
USGS topographical maps of your area
Q
Detailed USGS seismic maps that specifically identify earthquake fault traces (available only for areas of high
seismic risk)
Q
Maps issued by state departments of geology or natural resources
Q
Land use policy or development maps, available from county or city zoning offices. The use of these maps is
mandatory for all nonresidential and large-scale residential construction. They may be referred to as “special
studies zones” maps
Q
Seismic risk maps. These are based on the location, number, and magnitude of historic earthquake events that
have taken place and been recorded during the last 200 years
Q
Maps indicating areas of structurally defective grounds, generally developed by state or local agencies to
include (a) poor soils and (b) landslide areas
Q
Landslide susceptibility maps, available from USGS for specific regions in the U.S. The U.S. Department of
Housing and Urban Development also has data and maps of landslide problems.
Q
Maps noting geologic hazards; may he included in your local building codes
Q
Microzonation maps include data on the anticipated maximum earthquake intensity, active faults, geologic
units, special studies zones, ground response, liquefaction susceptibility, landslide susceptibility, and zones of
potential tsunami inundation. Available from zoning offices.
Q
Soil studies of the area produced for agricultural purposes, either by USDA or local agencies
Q
Soil maps produced by the Soil Conservation Service
A G U
/
F E M A
133
S
E I S M I C
S
L E U T H S
