Landslides

Landslides affect all 50 states and U.S. territories, where they cause 25 to 50 deaths and more than $1 billion in damages each year. Geoscientists study and monitor landslides to identify at-risk areas, prepare populations, and improve our understanding of why, when, and where landslides happen.

Basics

2014 Oso, Washington Landslide. Image Credit: USGS/Photo by Mark Reid

Landslides are masses of earth, rock, or debris that move down slopes. Landslides are triggered by one event, but many causes can weaken slopes over time and make them more likely to fail when there is a triggering event. These causes can be both natural and artificial. Landslides often occur in areas with oversteepened slopes, weak soils/bedrock, or de-vegetated slopes (whether by human deforestation or natural events such as wildfires).[1] Some of the most damaging landslides are triggered by water, typically from intense short-term rainfall or long-term saturation of the slope. Both natural and human activities (such as irrigation or seepage) can saturate hillsides. Earthquakes and volcanic eruptions also cause damaging landslides.[1]   Read more

Frequently Asked Questions

Latest News

landslide
(2017-04-10)
March 22, 2017 Senators Maria Cantwell (D-WA) and Lisa Murkowski (R-AK) introduced the bipartisan National Landslide Preparation Act (S.698) on March 22. The bill directs the U.S. Geological Survey (USGS) to establish a National Landslide Hazards Reduction Program. This program would identify and...
Mount St. Helens
(2016-07-28)
July 12, 2016 The Hazards Caucus Alliance, a network of organizations that promotes nationwide natural disaster resilience, held a briefing to highlight the role that science plays in protecting communities that are vulnerable to lahars. Introductory remarks from Senator Lisa Murkowski (R-AK) were...
Capitol at night
(2016-04-11)
March 17, 2016 Congresswoman Suzan DelBene (D-WA) has introduced new legislation  in an effort to decrease losses and damages as a result of landslides.  The new bill, the National Landslide Loss Reduction Act (H.R. 4776) would create the National Landslide Hazards Reduction Program and two...

Case Studies & Factsheets

CI_CaseStudy_2017_1_VolcanicLandslides_thumb.JPG

More than just volcanic eruptions Volcanic eruptions are a serious hazard. But at many stratovolcanoes in Washington, Oregon, Northern California, and Alaska, landslides and debris flows can be just as dangerous. Some of these - especially volcanic mudflows (lahars) - are directly triggered by...

Fig. 1. A 1995 landslide in Overland Park, Kansas, destroyed two homes and damaged four lots. Credit: Kansas Geological Survey

Defining the Problem Damaging landslides occur even in vertically challenged states like Kansas (Fig. 1). It is important to be able to delineate landslide hazard areas in order to develop appropriate land-use plans. In Leavenworth County, Kansas, geologic maps combined with maps of landslide...

Fig.1. Home in Oakland, CA, destroyed by landslides in 1958. Source: J. Coe, USGS

Defining the Problem The geologic history of the Oakland, California, area has produced steep hillsides and unstable rock and soil that generate damaging landslides during severe storms and wet winters (Fig. 1 and 2). During the 1997-98 rainy-season, the two-county area surrounding Oakland...

Fig. 1. Homeowners and emergency managers are still coping with debris flows and the aftermath of the 2002 Missionary Ridge wildfire near Durango, CO. Credit: P. Winkworth

Defining the Problem Wildfires, such as the Missionary Ridge fire that burned for more than a month in 2002 near Durango, Colorado (Fig. 1), and their aftermath can cause subsequent property and environmental damage. Many areas denuded by the fire are now susceptible to rapid erosion during...

Fig. 3. U.S. Highway 85 crossing the Little Missouri River. Seventy-five percent of the rocks in this photograph, all of those in the foreground and the rocks along the north valley wall in the background have slid and are out of place. Credit: E. Murphy

Defining the Problem U.S Highway 85 and ND Highway 22, along with numerous county roads, buildings, pipelines, and power lines, have been constructed over existing landslides in the Little Missouri Badlands of western North Dakota. Since 1980, the repair and rerouting of damaged sections of...

Research Database Publications

Living with Unstable Ground, AGI
2009, American Geosciences Institute (AGI)
Most of us take the stability of the ground for granted. However, many ongoing natural processes and human activities, and occasionally complex combinations of both, displace the ground. Whether ground displacements are large and catastrophic or small and slow, their cumulative impact during the...
Cover of RI_34_12; Source: Kentucky Geological Survey
2015, Kentucky Geological Survey (KGS)
Kentucky Transportation Cabinet maintenance cost data for landslides and rockfalls were associated with geology along Kentucky roadways in a three-phase study. Work-order costs collected over 7 yr were divided into 1-mi segments, and the segment midpoints were assigned to geologic units in order to...
Fig. 3. U.S. Highway 85 crossing the Little Missouri River. Seventy-five percent of the rocks in this photograph, all of those in the foreground and the rocks along the north valley wall in the background have slid and are out of place. Credit: E. Murphy
2004, American Geosciences Institute (AGI)
Geologic maps can help to show which areas may be more prone to landslides and therefore directly assist in making optimum engineering design choices.
Cover of IC_31_12; Source: Kentucky Geological Survey
2014, Kentucky Geological Survey (KGS)
The Kentucky Geological Survey is compiling a landslide inventory database to better document the distribution and geologic context of Kentucky’s landslides. The database provides users with easy access to landslide information, raises awareness of landslide causes, and will help prevent property...
Cover of B-55; Source: Colorado Geological Survey
2015, Colorado Geological Survey (CGS)
On May 25th, 2014 the longest landslide in Colorado’s historical record occurred in west-central Colorado, 6 mi southeast of the small town of Collbran in Mesa County. Three local men perished during the catastrophic event. The landslide was 2.8 miles long, covered almost a square mile of the West...
Cover of fs2016-3094; Image credit: U.S. Geological Survey
2017, U.S. Geological Survey (USGS)
The U.S. Geological Survey (USGS) Landslide Hazards Program conducts landslide hazard assessments, pursues landslide investigations and forecasts, provides technical assistance to respond to landslide emergencies, and engages in outreach. All of these activities benefit from the availability of...
Cover of fs_landslide_processes; Source: Washington Division of Geology and Earth Resources
2015, Washington Division of Geology and Earth Resources (WA DGER)
A landslide generally refers to the downhill movement of rock, soil, or debris. The term landslide can also refer to the deposit that is created by a landslide event. This fact sheet is meant to provide general information only; real landslides have many variables.
Cover of Guide for Homeowners; Credit: DOGAMI / WA GER
2017, Washington Division of Geology and Earth Resources (WA DGER)
This pamphlet for homeowners provides information about landslides as it realtes to their home and property. It includes information about landslide warning signs and who to contact if homeowners suspect active landslides on their property. This guide was developed by the Oregon Department of...
Cover of factsheet; Image credit: Hazards Caucus Alliance
2014, Hazards Caucus Alliance (HCA)
Landslides are a destructive geologic hazard with localized but significant impacts. In an average year in the United States, landslides cause the deaths of 25 to 50 people and economic losses of at least $2 billion. State and local entities take significant responsibility for landslide mitigation...
Cover of SP-30; Source: Colorado Geological Survey
1986, Colorado Geological Survey (CGS)
Study of Ouray–a small mountain city with a long history of destructive debris flows. Includes description of past events, local geology, hydrology, damage incurred, mitigation attempts and costs, and map of hazard zones.