For the more information about the geologic resources of the National Park Service, please visit http://www.nature.nps.gov/geology/.
Geologic Monitoring
Slope Movements
What are slope movements?
Slope movements refer to the downslope transfer of soil, regolith and rock under the influence of gravity. Slope movements may occur over seconds or even years. Some examples include:
Why does the National Park Service monitor slope movements?
Collection of data on regional slope movements is beneficial for
- assessment of landslide hazards and risk,
- which is in turn important for park operations and planning.
- Monitoring Book
- Resource Facts
- Case Study
Geological Monitoring Book
Vital Signs Monitored
- Types of landslides
- Landslide triggers and causes
- Geologic materials in landslides
- Measurement of landslide movement
- Assessing landslide hazards and risks
Chapter 11
Monitoring Slope Movements (PDF - 1.88MB)
Slope movements, including landslides and extremely slow soil creep occur throughout the United States and within many national parks. The collection of vital signs of regional landslide information, referred to as monitoring, is not only scientifically useful, but is beneficial for assessment of landslide hazards and risk, which is in turn important for regional operations and planning.
This chapter will describe several different methods of monitoring slope movements to evaluate landslide hazards and risks.
NPS Slope Movement Facts
Geologists use the term "mass wasting" for slope movements as described above.
Mass wasting effects can be seen in every state and in every national park.
More than 400 rockfalls have been documented in Yosemite National Park.
In 1996, a rockfall at Yosemite National Park generated an airblast with a wind speed comparable to a hurricane (~250 mph), which caused about a thousand trees to snap in the area.
Monitoring Slope Movements in the National Park Service
Monitoring Rock Fall Activity at Yosemite National Park
Although predicting rock falls is not yet possible, documenting and understanding the events that happen is an important step toward this goal.
| Vital sign | Rationale | Method |
| Changes in cliff morphology: | Can determine locations and volume of rock fall, and pre-failure geometry of cliff face | Repeat LiDAR scanning coupled with high-resolution photography |
| Atmospheric conditions: | Air temperature and humidity can affect stability of slopes | Direct observations / field measurements |
| Exfoliation joints: | Exfoliation joints dictate rock fall locations | Field mapping & in-situ stress measurements |
| Additional Information |
| Yosemite Panoramic Imaging Project |
| Yosemite Science Publication - High-resolution Tools for Understanding Geologic Processes (PDF - 380 KB) |
Related Links
- Geologic Monitoring Book, Chapter 11 - Monitoring Slope Movements (PDF - 1.88MB)
- Mass Wasting in the National Parks
- Avalanches
- Landslide Hazards in the NPS (PDF - 113KB)
- Geohazards and Risk: Rock Mechanics Assessments (PDF - 86KB)
Last Updated: April 16, 2012
