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It’s one of the few natural disasters that comes with its own road sign: the landslide. Most of us can remember driving past a yellow warning sign featuring a steep slope with rocks falling down it. So, what exactly is a landslide, and how can you prepare to stay safe if one happens?
What’s a landslide?
A landslide is a mass of rock, earth or debris falling down a slope. A mudslide, also known as a debris flow, is a type of quick-moving landslide that liquefies, tends to move in channels and can reach speeds in excess of 30 miles per hour. Landslides happen when a slope’s natural stability is disturbed and often occur in conjunction with earthquakes, volcanic eruptions or heavy rainfalls.
Landslides happen in all U.S. states. Some areas are more susceptible to landslides than others, such as slopes where wildfires and development have left behind little vegetation; slopes that have been modified to make room for buildings and roads; and areas at the bottom of steep slopes and canyons.
While landslides can happen with little warning, there are signs you should watch out for, especially if you live in an area prone to landslides and where landslides have happened before. Among the many signs of a landslide are changes in the landscape, such as the flow of rainwater; new cracks in a building’s foundation or in paved areas; tilted trees, fences and utility poles; and the sounds of moving debris.
Build safely, plan ahead
If you live in an area prone to landslides, consider hiring a professional to conduct a geological hazard assessment to learn how and if you should make safety upgrades to your home. Some ways to prevent and minimize damage to your home may include installing retaining walls or creating channels that direct mudflows away from your home. Also, talk to your insurance agent, as some homeowners may be protected via flood insurance policies.
The first step in preparing to stay safe in a landslide is information — learn if and how often landslides and mudslides have happened in your community and pinpoint your area’s evacuation routes and shelters. As with most disaster preparation, develop a household emergency plan that addresses the possibility that your family may be separated when a landslide happens. Put together a portable emergency stockpile kit you can take with you in case of evacuation.
During and after a landslide
Be alert during heavy rainfalls, especially if you live in a landslide-prone area. It’s a good idea to have a battery-operated radio on hand to stay on top of weather updates and instructions from emergency officials. If you’re worried, consider leaving your home. If you stay home, move to the highest level of your home.
Listen for rumbling sounds such as boulders knocking against each other and look for tilted trees and bare spots on hillsides. If you live near a stream or channel, watch out for a sudden increase or decrease in water flow as well as a change from clear to muddy water. If you believe a landslide is about to happen, call the authorities for more information. If you and your household are in danger, evacuate — removing yourself from the landslide’s path is the best way to stay safe.
If evacuation is not possible, curl into a tight ball, protect your head and take cover under a sturdy piece of furniture.
After a landslide, continue listening to instructions from emergency officials. Stay away from the landslide site, as more landslides could happen. If you can do so safely, check for injured residents and lend a hand to any neighbors you know will need special assistance. Report downed utility lines and cracked roadways to the authorities.