|Disasters & Emergencies
What are Landslides?
A landslide is a mass of rock, earth, or debris moving down a slope. They are activated by rainstorms, earthquakes, volcanic eruptions, fires, and by human modification of the land.
What is a Mudflow?
- Mudflows (or debris flows) are rivers of rock, earth, and other debris saturated with water.
- They develop when water rapidly accumulates in the ground such as during heavy rainfall or rapid snowmelt, changing the earth into a flowing river of mud or slurry.
- Landslides may be very small or very large and can move from slow to very high speeds.
- It is estimated that landslides cause between 25 and 50 deaths each year in the U.S. and thousands more in vulnerable areas all around the globe.
- Mudflows may be very small or very large; flowing rapidly down slopes or through channels, and can strike with little or no warning.
- A mudflow can travel several miles from its source, growing in size as it picks up trees, vehicles, and other materials along the way.
Landslide Warning Signs
- Landslides may occur in all U.S. states/territories; California, West Virginia, Utah, Kentucky, Tennessee, Puerto Rico, Ohio, and Washington are at greatest risk.
Actions to Consider
- Doors or windows begin to stick or jam.
- New cracks appear in plaster, tile, brick, or foundations.
- Outside walls, walks, or stairs begin pulling away from the building.
- Slowly developing, widening cracks appear on the ground or on paved areas such as streets or driveways.
- Underground utility lines break.
- Bulging ground appears at the base of a slope.
- Fences, retaining walls, utility poles, or trees tilt or move.
- The ground slopes downward in one specific direction and may begin shifting in that direction under your feet.
- Be alert for sudden increases or decreases in water flow and a change from clear to muddy water if you are near a stream or channel.
- Create an evacuation plan for your family and have a backup route in mind.
- Be prepared to evacuate if instructed to do so.
- Listen for unusual sounds such as trees cracking or boulders knocking.
- Plant ground cover on slopes and build retaining walls.
- Stay indoors. Move to a second story if possible.
- Take cover under a desk, table, or other piece of sturdy furniture.
- Get out of the path of the landslide or mudflow. Run to the nearest high ground in a direction away from the path. Do not delay! Save yourself, not your belongings.
- Run for the nearest shelter such as a group of trees or a building if rocks and other debris are approaching.
- Curl into a tight ball and protect your head if escape is not possible.
Did You Know...
- Stay away from the slide area; there may be danger of additional slides.
- Check for injured or trapped people near the slide area. Provide first aid and CPR if trained to do so.
- Listen to local radio or television stations for the latest emergency information.
- Help a neighbor who may require special assistance - large families, children, elderly, and individuals with disabilities.
- Check the building foundation, chimney, and surrounding land for damage. Be especially careful to check for downed power lines and gas lines that may have ruptured.
- Replant damaged ground as soon as possible since erosion caused by loss of ground cover can lead to flash flooding.
- Report property damage to your insurance agent immediately.
The May 1980 eruption of the Mount St. Helens volcano caused the largest landslide in history - a rock slide-debris avalanche large enough to fill 250 million dump trucks.
Contact your local or Installation's Office of Emergency Management for more information.