Picture taken in an old Asian Village in Japan. The picture shows a devastating mudflow which had taken place many years back and had destroyed nearly the entire village.
Mudflows are very quick flows of earth materials which behave more like a liquid rather than a solid. They involve finer sediments and are less viscous than earthflows. Thus, they travel at a high speed too. Mudflows occur on lower slopes than earthflows and are common in areas with very sparse vegetation. Torrential downpours also contribute to the occurrance of mudflows as they add a huge amount of water content to the earth materials.
Because of the high velocity and long distance travel, mudflows can be hazardous to people. Mudflows that result when a volcanic eruption causes ice to melt or water to be drained from the crater lakes. These mudflows are termed as lahars. Sometimes, lahars can be extremely hot when they are created as a result of eruptions of hot tephra.
Causes of Mudflows :
- Role of water and heavy rainfall
- Volcanic eruptions
Other Examples of Mudflows :
- 1980 eruption of Mount St. Helens which triggered off mudflows and debris avalanche
- 1985 eruption of Nevado del Ruiz volcano in Canada which triggered off devestating mudflows, killing 23,000 people
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