These are among the most destructive of mass movements. May be triggered by rain or melting snow, or earthquakes. Landslide in the Great Smoky Mountains National Park, Tennessee, near Clingman's Dome. First image is from 1976, and second image is in the same spot in 1980. Note the increase in the size of the landslide over four years.
Debris flows or mudflows Commonly occur in volcanic areas, where they are called lahars .
Also occurs at the toe of slumps. Includes the liquifaction associated with earthquakes. Creep A SLOW downhill movement of soil and regolith. Creep results in tree trunks that are curved at the base, tilted utility poles, fence posts, and tombstones, and causes retaining walls to be broken or overturned. Solifluction Occurs in areas underlain by permafrost.