'David and Goliath' battle against mud volcano

energy

Scientists are observing with keen interest and some scepticism a novel attempt in Indonesia to plug a "mud volcano" by dropping hundreds of concrete balls into its yawning crater. This David and Goliath battle is a world first with high human and environmental stakes.
The unique solution was dreamt up by three scientists at the Bandung Institute of Technology (ITB), which produces Indonesia's top engineers.

Their mission is to "tame" the uncontrollable mud flow which erupted on May 29 last year close to the town of Sidoarjo on the island of Java. According to the majority view, the catastrophe was caused by exploratory gas drilling which pierced a layer of strata under pressure at a depth of 2,830 metres (9,340 feet). In the past 10 months the disaster has claimed a dozen lives and forced more than 15,000 people to flee their homes. Whole villages, a highway and about 25 factories were swallowed by the sea of stinking grey mud which is still advancing. Mud continues to spew forth at a rate of between 100,000 and 150,000 cubic metres a day, equivalent to the volume of about 50 to 75 Olympic size swimming pools. After an intense brainstorming session, the ITB trio came up with the idea of creating a giant plug, formed from an interlaced network of heavy chains and balls. "We realized this mud volcano is rather unique so we needed a unique solution," Satria Bijaksana, one of the three engineers, told AFP. Each chain, weighing 196 kilograms (430 pounds), comprises four balls: two of 80 kilos and two of 18 kilos. In order to release them in the centre of the 50-metre wide crater into the scorching and viscous liquid, it was necessary to build a bridge equipped with a mobile crane. Since the end of February, the chains have been released one after another and disappeared into the bowels of the volcano. The unfathomable crater has already swallowed nearly 400 chains as if they were pills. Some officials say they have detected a "fall in flow," while recognising that it was difficult to evaluate and that hundreds more chains would be necessary. Professor Bijaksana defends, with modesty, his novel method. "We are just three scientists who try their best. We will fight." This battle of man against powerful geological forces has aroused interest far beyond the borders of Indonesia, an archipelago which seems to concentrate all conceivable natural disasters.
"We do receive emails from all over the world," said the 42-year-old Indonesian. But opinions are often circumspect. "So far no one has attacked this problem directly," the geologists insist. Mads Huuse from the University of Aberdeen in Scotland said more data was needed to determine if there really was a feasible method of stopping the flow. The geologist warned it was impossible to say how long the volcano would continue to spew. "In the worst case the volcano could go on for many years," Huuse told AFP in an email interview. "I don't think anyone can say for sure." Fellow geologist Richard Davies said he was also intrigued by the plan but remained sceptical about its chances of success. "No one has ever stopped a mud volcano," he told AFP. The earth sciences expert from Durham University in northeast England was the first to carry out a study of the mud volcano dubbed "Lusi," (from "lumpur," the Indonesian word for mud, and "Sidoarjo"). Beware of "oversimplification," he said. The underground route of the mud flow is too winding and the volume piped out too vast to be stopped by concrete balls and chains, according to him. "They think it's like a funnel," Davies said, although he believes "the plumbing of the mud volcano is probably not simple." "It could be composed of a number of complex fractures," he said. The chained balls "may have some small effect but I would be surprised if they had an (significant) impact." Davies however is more optimistic about an incident which occurred on March 19, when Lusi abruptly ceased spewing mud for 35 minutes before resuming. "The fact it has stopped completely suggests something quite catastrophic happened in the conduit. Probably it collapsed," he said. According to the geologist, the "coughing" is a good sign. The volcano could choke itself, due to the natural subsidence of the walls the crater. "Perhaps it is starting to collapse," he said. © 2007 AFP