Banner Graphic a collage of images representing various USGS activities

Geographic Distribution of Major Hazards in the US

This set of six maps have been constructed to emphasize areas in the contiguous 48 states where there is a relatively high risk or relatively frequent actual occurrences of four hazards (floods, earthquakes, landslides and volcanic eruptions), for which the USGS has major monitoring or reporting responsibility, plus hurricanes and tornadoes. Alaska and Hawaii, which are high-risk areas for most of these hazards, are not shown, in part because the equivalent detailed hazard maps do not yet exist. Areas in the 48 states not at high risk from any of these hazards are not necessarily "safe". They may be exposed to other hazards, such as winter storms or drought.

Map 1. Groundshaking Hazards from Earthquakes in the Contiguous United States

Map 2. Volcanic Hazards (based on activity in the last 15000 years)

Map 3. Landslide Areas in the Contiguous United States

Map 4. General Areas of Major Flooding, January 1993-December 1997

Notes for Tornado, Hurricane Maps

As for the first four, these two maps have been constructed to emphasize areas in the contiguous 48 states where there is a relatively high risk or actual occurrence of tornadoes or hurricanes. In both cases, the information and statistical interpretations come from NOAA. Expanded versions of these maps have recently appeared in an insert map in the July 1998 National Geographic.

Map 5. Map Showing Hurricane Activity in the Conterminous United States

Map 6. Map Showing Tornado Risk Areas in the Conterminous United States

To see the combined effect of all six of these hazards, click the map at the right and watch as the distribution of each is added to the previous hazards. By considering only these six hazards, and coloring in only areas of fairly high risk, we have succeeded in coloring in most of the area of the contiguous 48 states. Each state is at substantial risk for at least one hazard, and some are at risk for several. When we look at where the remaining uncolored areas are, and remember that there are other hazards [winter storms (blizzards, ice storms), or hail, or drought] which have not been included in this set of maps, it is clear that there is no place where we are out of reach of the powers of Nature.

Contact: Hazards Theme Coordinator