Javanese Mud Volcano Remains Active
The "Lusi" mud volcano, which was newly formed on Java in 2006, will probably remain active for at least a few months, but more likely for several years, and is likely to pump between 7,000 and 150,000 cubic meters of hot mud per day in the future. This yielded the first comprehensive scientific investigation of the geological phenomenon that first erupted on May 29, 2006.
The cause of Lusi's emergence is most likely the oil and gas exploration wells recently undertaken in this Indonesian province, according to Richard Davies, lead investigator at Durham University. Typically, exploration companies prevent these types of side effects by sealing the well with some form of steel casing to stabilize it. At Lusi, this appears to have failed while the drill rod struck highly pressurized, water-saturated limestone. Cracks in the layers of rock then broke open, allowing a mixture of water and mud to work its way up. Something similar happened off the coast of Brunei in 1979 during test drilling - it was only almost thirty years later that this hole was closed again.
The Porong district on Java is now threatened with a subsidence area of around ten square kilometers, since the central vent of the volcano will collapse in the near future and then form a crater. However, this basin is at least partially filled up by the mud masses, so that the approximately 11,000 displaced people in the Lusi area have no chance of returning to their old villages for the time being. So far, all attempts to stem the flow of material or at least to limit it locally have failed. Plans to dump the sludge into a nearby river have met with massive criticism from environmentalists who fear contaminated drinking water and fish kills. However, according to geologists, it would not be possible to prevent drainage into the water anyway.
The severe earthquake that was originally suspected and which shook the island just two days before is ruled out as the cause, according to Davies. This was verified by comparative geological examples. In addition, Lusi is an isolated case, because there are no other geotectonic occurrences of a similar nature in the regions affected by the earthquake.