Real-Time Monitoring of an Active Landslide above U.S. Highway 50, California
During January 1997, several large landslides closed Highway 50 between Placerville and South Lake Tahoe, California. The photograph above shows the catastrophic Mill Creek landslide that closed Highway 50 for 4 weeks. A number of other landslides are currently active in this corridor.
Photograph of the Mill Creek landslide that closed Highway 50 for 4 weeks. CALTRANS Photo by Lynn Harrison, 1997
The U.S. Geological Survey, in cooperation with the Eldorado National Forest, has installed monitoring instruments on one currently active landslide that has the potential to affect Highway 50. Data from these instruments are used to detect changes in local conditions including:
- Rainfall
- Groundwater data from pressure sensors
- Movement data from displacement sensors
- Ground vibration from geophones.
Data are collected every 15 minutes and displayed on graphs. In many landslides, infiltration of rainfall or rapid snowmelt increases groundwater pressures. These elevated pressures can, in turn, trigger landslide movement.
For More Information
Contact Information
Mark Reid
mreid [at] usgs [dot] govU.S. Geological Survey
Landslide Hazards
345 Middlefield Road MS 910
Menlo Park, CA 94025-
Rick LaHusen
rlahusen [at] usgs [dot] govU.S. Geological Survey
Volcano Hazards
1300 SE Cardinal Court, Building 10, Suite 100
Vancouver, WA 98683