Monitoring Volcano Ground Deformation

Changes at the Surface Tell us about the Subsurface

Mount St. Helens dome.

Changes to the surface of a volcano (volcano deformation) can provide clues about what is happening deep below the surface. Most volcano deformation can only be detected and measured with precise surveying techniques. The Volcano Hazards Program has installed networks of sensitive deformation instruments around volcanoes to monitor changes over time. These instruments, along with satellite-based technologies help us to better understand the volcanoes we watch and allow us to provide eruption warnings.

  • Scientist and helicopter at GPS site.


    Mapping individual ground locations Earth-orbiting satellites.

  • InSAR image of Yellowstone with multiple color bands.


    Mapping ground deformation of large areas using radar images from Earth-orbiting satellites.

  • Cascade eruptions poster


    Measuring tiny changes in the slope angle or "tilt" of the ground.

  • using an edm at kilauea


    Measuring the distance between benchmarks placed on a volcano tens to thousands of meters apart.