11 Facts About Landslides

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1. Landslides occur when masses of rock, earth, or debris move down a slope. Debris flows, also known as mudslides, are a common type of fast-moving landslide that tends to flow in channels.^[Neuman, Scott. "In U.S., Mudslides Common, But Usually Few Deaths." NPR. http://www.npr.org/blogs/thetwo-way/2014/03/28/295823075/in-u-s-mudslides-common-but-usually-few-deaths (accessed April 1, 2014).]
2. Mudslides develop when water rapidly accumulates in the ground and results in a surge of water-saturated rock, earth, and debris. Mudslides usually start on steep slopes and can be activated by natural disasters.^[California Department of Public Health. "Landslides and Mudslides." Be Prepared California. Accessed March 30, 2014. .]
3. Areas where wildfires or human modification of the land have destroyed vegetation on slopes are particularly vulnerable to landslides during and after heavy rains.^[California Department of Public Health. "Landslides and Mudslides." Be Prepared California. Accessed March 30, 2014. .]
4. Landslides and mudflows can cause tons of damage, some of which can lead to actual injury including: Rapidly moving water and debris can lead to trauma; Broken electrical, water, gas, and sewage lines that can result in injury or illness.^[Centers for Disease Control and Prevention. "Landslide (Mudslide) Safety." Emergency Preparedness and Response. Accessed March 30, 2014. .]
5. Every year, landslides in the U.S. cause roughly $3.5 billion in damage and kill between 25 and 50 people.^[Reducing losses from landsliding in the United States. Washington, D.C.: National Academy Press ;, 1985.]
6. Casualties in the U.S. are primarily caused by rock falls, rock slides, and quick-moving debris.^[Neuman, Scott. "In U.S., Mudslides Common, But Usually Few Deaths." NPR. Accessed March 30, 2014. .]
7. There have been many landslides throughout the years including the Rio de Janeiro landslide in 2011 which caused over 600 deaths.^[Bioexpedition. "Landslide." Basic Planet. Accessed March 30, 2013. .]
8. It is not just on earth in which landslides occur. Throughout the solar system there has been evidence that landslides have occurred, on Mars and Venus specifically. Scientists have had trained satellites orbiting the planets to view the landslides^[Bioexpedition. "Landslide." Basic Planet. Accessed March 30, 2014. .]
9. The May 1980 eruption of Mount St. Helens caused the largest landslide in history. A rockslide debris avalanche large enough to fill 250 million dump trucks to the brim traveled about 14 miles, destroying, amoung many things, nine highway bridges.^[Neuman, Scott. "In U.S., Mudslides Common, But Usually Few Deaths." NPR. Accessed March 30, 2014. .]
10. The debris avalanche from the eruption also formed several new lakes by damming the North Fork Toutle River and its tributaries.^[Neuman, Scott. "In U.S., Mudslides Common, But Usually Few Deaths." NPR. Accessed March 30, 2014. .]
11. On steep hillsides, debris flows begin as shallow landslides that liquefy and accelerate. A typical landslide travels at 10 miler per hour, but can exceed 35 miles per hour.^[National Disaster Education Coalition. "Landslide and Debris Flow (Mudslide)." Disaster Center. Accessed March 30, 2014. .]