Can Landslides be Predicted?

without destroying the terrain completely. These may be seasonal, continuous, or progressive in nature. Progressive creeps gain momentum over time. You'll see evidence of creep if trees are bent or if there are ridges in the soil that is currently creeping.

• Lateral spreads – this is a unique type of land movement where the slope is flat or very slight. The movement of material extends out laterally due to liquefaction of very saturated earth and sediment with very little cohesion to the pieces.

Earthquakes can trigger these because of ground shaking. If water is added to loose material, you can get lateral spread of this liquefied stuff in a progressive fashion, where momentum builds up over time. The failure begins small but spreads fairly quickly in a complex series of events that lead to this being called a complex landslide, depending on the circumstances.

• Solifluction – this is due to a combination of flow and creep that falls in sheets on steeper slopes.

In a typical rock avalanche, for example, you have several factors to consider regarding its behavior and what to expect. If the initial drop was steep and fast, the runout over space does not need to involve much of a decline and could involve an uphill excursion of material. If the mass moves fast enough, friction as the mass slides will heat up the underground area. This can further reduce the shear stress and can speed the avalanche. Heated water can vaporize to create a steam that carries the material downhill like a hovercraft on air. Minerals can melt under high temperatures as well. Friction can also crush some rocks into a powder that will lubricate the falling mass.

CAN LANDSLIDES BE PREDICTED?

Landslides are major hazards that can lead to loss of important infrastructure, property, and human lives. It is possible to map areas in order to predict whether or not a landslide of some type is possible. If an area is at risk, decisions can be made to protect people and to avoid human triggers to the landslide areas.

Geologists look at the geology of the land, the type of rock and soil in the area, what is being done to the area with regard to construction or agriculture. They also look at the