USGS Newsroom

The U.S. Geological Survey alerted state and federal agencies today to the increased potential for landslides in the mountainous regions of Georgia, Alabama, Tennessee, Kentucky, Pennsylvania, South Carolina, North Carolina, Virginia, West Virginia, Ohio and Maryland due to anticipated heavy rainfall from Hurricane Ivan.

"Given the wet soil conditions we already have in many of these areas, the risk of numerous, fast-moving landslides is significant," Gerry Wieczorek, USGS landslide specialist said. "Residents in landslide-prone areas and anyone in mountainous areas should be aware of the warning signs and be prepared to move quickly. Intense rains have triggered landslides in the area before."

The slope of the land, the type of geology, ground saturation, and rainfall intensity and duration all play major roles in triggering landslides. During the inland passage of Hurricane Frances through mountainous western North Carolina, many areas received between 10 and 16 inches of rainfall over 24 hours, which triggered at least 20 isolated landslides that blocked highways and damaged or destroyed houses.

Currently, the National Weather Service of NOAA forecasts up to 15 inches of rainfall during the next couple of days (Sept. 16-19) through the southern/central parts of the Appalachian Mountains as far north as Pennsylvania. If heavy rainfall occurs as predicted, numerous landslides could occur in mountainous areas along the projected path of the storm in the States of Georgia, Alabama, Tennessee, Kentucky, South Carolina, North Carolina, Virginia, West Virginia, Ohio Maryland, and Pennsylvania.. The USGS will continue to monitor the predicted track of Hurricane Ivan and issue landslide alerts to other states in its path if necessary.

Landslides are powerful. People living in these areas should be aware of the danger during severe weather and be ready to act if the situation warrants.

Advice for residents in affected areas:

Before the storm:

1. Become familiar with the land around you. Learn whether landslides have occurred in your area. Slopes where landslides have occurred in the past are likely to experience them in the future.
2. Watch the patterns of storm-water drainage on slopes near your home, and note especially the places where runoff water converges, increasing flow over soil-covered slopes. Watch the hillsides around your home for any signs of land movement, such as small landslides or debris flows or progressively tilting trees.
3. Contact your local authorities to learn about the emergency-response and evacuation plans for your area and develop your own emergency plans for your family and business.

During the storm:

1. Stay alert and stay awake. Many landslide fatalities occur when people are sleeping. Listen to a radio for warnings of intense rainfall. Be aware that intense short bursts of rain may be particularly dangerous, especially after longer periods of heavy rainfall and damp weather.
2. If you are in areas susceptible to landslides, consider leaving if it is safe to do so. Remember that driving during an intense storm can itself be hazardous.
3. Listen for any unusual sounds that might indicate moving debris, such as trees cracking or boulders knocking together. A trickle of flowing or falling mud or debris may precede larger flows. If you are near a stream or channel, be alert for any sudden increase or decrease in water flow and for a change from clear to muddy water. Such changes may indicate landslide activity upstream, so be prepared to move quickly. Don’t delay. Save yourself, not your belongings.
4. Be especially alert when driving. Embankments along roadsides are particularly susceptible to landslides. Watch the road for collapsed pavement, mud, fallen rocks, and other indications of possible debris flows. Never drive across a flooded road.

For more information, visit the following websites:

Debris-Flow Hazards in the United States: http://pubs.usgs.gov/fs/fs-176-97/fs-176-97.html

Landslide Hazards: http://pubs.usgs.gov/fs/fs-0071-00/

Debris-Flow Hazards in the Blue Ridge of Virginia: http://landslides.usgs.gov/html_files/nlic/blueridge.htm