Earthquakes or heavy rains can trigger landslides. Erosion caused by rivers, waves, glaciers, or construction projects creates the steep slopes necessary for landslides.
Some landslides are large enough to create lakes by damming up rivers.
Landslides can be destructive. In 1903, a major landslide in the Canadian coal-mining town of Frank, Alta., buried part of the town and killed 70 people. See Alberta on World Book Online . John G. Anderson, Ph.D., Professor, Univ. of Nevada, Reno. How to cite this article.