Mud volcano eruptions likely to continue for a quarter of a century
(28 February 2011)
The world's biggest mud volcano will continue erupting for another 26 years, according to experts from Durham University.
The first detailed estimation of the longevity of the Indonesian mud volcano, Lusi, predict that the equivalent of 56,000 Olympic-sized swimming pools worth of mud will be emitted by the volcano before it calms down.
In 2006, the volcano killed 13 people and displaced thirteen thousand families in East Java, Indonesia, when it erupted. At its height, the Lusi crater was oozing enough mud to fill over 50 Olympic-sized swimming pools every day.
The Durham findings, published in the Journal of the Geological Society, London, used pressure estimations from a nearby borehole and knowledge of the volcano's plumbing.
As the mud continues to spew out, the team estimates that the volcano area itself could subside by up to half a kilometre.
Professor Richard Davies, Department of Earth Sciences, Durham University, said:
"The mud from the Lusi volcano has engulfed a huge area of the Porong subdistrict of Sidoarjo, Eastern Java, but how long it will continue to be a hazard for has been unknown.
"Our estimate is that it will take 26 years for the eruption to drop to a manageable level and for Lusi to turn into a slow bubbling volcano.
"The calculation should enable a better assessment of the final impact of the disaster and gives the inhabitants of Sidoarjo an indication of how long they can expect to be affected by mud from the volcano."
The Durham team asked the question: how long will it take for the volcano's mud flow to fall to 10% of its initial flow rate? The team calculated the flow based on observations of pressure of the source of water from a nearby borehole, the properties of the rocks supplying the water to the volcano, and the volumes of mud that had already erupted over the first 3 years. These probability calculations ignore the effect of gas in the mud at Lusi, which presents further complications for the people living nearby as it can ignite and could keep the volcano going for even longer.
Subsidence is causing 166 new vents and this, according to Professor Davies, is likely to be caused by the rupturing of shallow aquifers. Professor Davies' team is now looking at where these vents are likely to form. He believes these additional vents will cause further damage to homes, roads and the railway line.
Professor Davies said: "The world demand for oil and gas has inherent risks and while exploration may reap dividends, it can also cause problems. Drilling disasters are more common than people generally appreciate. Drilling is driven by our demand for oil and gas.''
In 2007 and 2008, a team of scientists led by Professor Davies produced evidence that drilling caused the mud volcano. Drilling company, Lapindo Brantas, have disputed the Durham claim that a nearby gas exploration well was the trigger for the volcano, blaming an earthquake which occurred 280km (174 miles) away.
Efforts to stem the flow of the mud volcano, including plugging the crater with concrete balls failed. The creation of giant dams has contained most of the subsequent mud flow.
Professor Richard Davies will be visiting the volcano to conduct further research on 11th and 12th May 2011.
The eruption began on 29 May 2006, close to Indonesia's second city of Surabaya.