Main Page | See live article | Alphabetical index


A landslide is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes, and shallow debris flows, see flow. Although gravity acting on an over steepened slope is the primary reason for a landslide, there are other contributing factors:

Slope material that become saturated with water may develop a debris flow or mud flow. The resulting slurry of rock and mud may pick up trees, houses, and cars, thus blocking bridges and tributaries causing flooding along its path.

Similarly, ice floes can form in rivers that are clogged with ice, but are generally much slower moving. Nonetheless, they can generate forces strong enough to collapse bridges.

An avalanche is similar in mechanism to landslide and it involves a large amount of ice, snow and rock falling quickly down the side of a mountain. Usually the ice builds in cornices or forms over a weaker layer of snow, creating the danger of an avalanche.

A pyroclastic flow is caused by a collapsing cloud of ash, poisonous gas and hot rocks from a volcanic explosion that moves rapidly down an erupting volcano.

First-draft text taken from USGS fact sheet, public domain

External links:

A landslide is also a near-unanimous election for a candidate in a vote, which has won by an overwhleming majority over to other candidates. Landslides sometimes occur when one candidate is perceived as much superior to the rest, or by imperfect voting methods. See bloc voting, and the unanimous 2002 re-election of Iraqi president Saddam Hussein, criticized by many on the outside as unfair.