Landslides, in and of themselves, constitute a major geologic hazard. They are widespread, result in $1-2 billion in damages and cause more than 25 fatalities each year. Landslides are frequently triggered by strong ground motions. They are an important secondary earthquake hazard.
Earthquake liquefaction, often referred to simply as liquefaction, is the process by which saturated, unconsolidated soil or sand is converted into a suspension during an earthquake. The effect on structures and buildings can be devastating, and is a major contributor to urban seismic risk.