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:'''Mudslide' redirects here, which is also the name of a cocktail.''
A 'mudflow' or mudslide is the most rapid (up to 80 km/h) and fluid type of downhill mass wasting. Similar terms are 'debris flow' (e.g. in high mountains), 'mudslide' (not very liquid) and 'mud stream' (e.g. from volcanoes; see also 'lahar').

However, these terms show a broad variety

★ in water content (from loamy mud up to almost liquid),

★ in material (wet soil, sandy sediments and/or silt, dirt, rock debris, volcanic ash, small plants and even trees)

★ and in length, total mass and velocity.

Contents

Triggering of mud flows

See also

External links

Triggering of mud flows

Heavy rainfall, snowmelt, or high levels of ground water flowing through cracked bedrock may trigger a movement of soil or sediments. Floods, debris- and mud flows may also occur when strong rains on hill or mountain slopes cause extensive erosion and/or what is known as "channel scour". The 2006 Sidoarjo mud flow may have been caused by rogue drilling.
Some broad mudflows are rather pretty and therefore slow (some meters/sec). Others begin very quick and continue like an avalanche. If "large enough" they can devastate villages and countrysides. They are composed of at least 50% silt and clay-sized materials and up to 30% water. Mudflows are common even in the hills around Los Angeles where they have destroyed many homes built on hillsides without sufficient support.
The point where a muddy material begins to flow, depends on its grain and the water content. Fine grainy material or soil has a smaller friction angle than a coarse sediment or a debris flow, but falling rock pieces can trigger a material flow, too.

See also

★ moisture content, solifluction, water saturation, torrent

★ slope failure, gully, alluvial plain

★ lava eruption, lava flow, Lahar

★ Glacial lake outburst flood

External links

★ How Mudslide works

★ Directed Technologies Drilling for mudslide prevention