Mud volcano is referred to formations created by geo-exuded slurries which also includes water and gases. Mud volcanoes produces no lava flows but instead are limited to slurries and water or gases. The mud produced by mud volcanoes is most typically formed as hot water, which has been heated deep below the earth's surface, begins to mix and blend with various subterranean mineral deposits, thus creating the mud slurry exudate. This material is then forced upwards through a geological fault or fissure due to certain local subterranean pressure imbalances. Mud volcanoes are associated with subduction zones and about 1100 have been identified on or near land. The temperature of any given active mud volcano generally remains fairly steady and is much lower than the typical temperatures found within igneous volcanoes. Mud volcano temperatures can range from near 100 °C (212 °F) to occasionally 2 °C (36 °F). Mud volcanoes may range in size from merely 1 or 2 meters high and 1 or 2 meters wide, to 700 meters high and 10 kilometres wide. Smaller mud exudations are sometimes referred to as mud-pots. The largest mud volcano structure, Indonesia's Lusi is 10 kilometres (6 mi) in diameter.
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| Lusi mud volcano devastation. |
On 29 May, 2006, a new mud volcano erupted in the Sidoarja regency of East Java, Indonesia. It buried villages and farmland in an area of nearly six square kilometres. Lusi is unlike other mud volcanoes in the way that it erupted with a continuously high flow of mud expelling at high temperature. The discharged mud now covers an area of 5.6 kilometres square and is being confined by man made earth embankments that surround the volcano on all sides.
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| Lusi mud volcano devastation. |
Initially, more than 100,000 tonnes a day was oozing to the surface. It is the biggest mud volcano in the world; responsibility for it was credited to the blow out of a natural gas well drilled by PT Lapindo Brantas, although some scientists and company officials contend it was caused by a distant earthquake.
At its peak Lusi spewed up to 180,000 m³ of mud per day. By mid August 2011, mud was being discharged at a rate of 10,000 m³ per day, with 15 bubbles around its gushing point. This was a significant decline from the previous year, when mud was being discharged at a rate of 100,000 cubic metres per day with 320 bubbles around its gushing point. It is expected that the flow will continue for the next 25 to 30 years. Although the Sidoarjo mud flow has been contained by levees since November 2008, resultant flooding regularly disrupt local highways and villages, and further breakouts of mud are still possible.
