Debate Renewed Over Cause of Lusi Mud Volcano

The village Sidoarjo inundated with mud (picture source)

A group of Russian scientists has renewed the debate over the cause of the Lusi mud volcano in East Java, Indonesia.  While the general scientific consensus has been that the volcano was caused by gas drilling in the area, the Russian team is pointing at earthquakes, which were initially considered but then dismissed, as the true cause of the mud volcano's eruption.

In May of 2006 the East Javan village of Sidoarjo was the victim of a volcano, a volcano that did not erupt lava, but rather scalding hot mud.  The volcano has been erupting ever since, expelling nearly 30,000 cubic meters of mud each day, and it is expected that the volcano is capable of a continuing eruption for the next 30 years.  Already the volcano has covered about seven square kilometers and about 11 villages, displacing about 40,000 people.  A network of levees was constructed in 2008 to try and contain most of the mud, but there is continuing concern about the potential of the levee system failing.

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Mud volcanoes are created in two different ways. One way is for fractures to develop in rock that lays like a cap over mud deposits.  If the mud is under pressure, it can rise to the surface through those fractures.  The other method is for an an earthquake to liquefy buried mud, through a process called soil liquefaction, that then travels through pre-existing fractures up to the surface.

A destructive earthquake and a series of after shocks that struck Java on the 27th of May was thought to have been the initial cause of the eruption, which occurred two days later on the 29th.  However, the earthquake was soon downplayed by scientists as not having been powerful enough to have caused the volcano.  Instead, evidence seemed to point to a gas drilling operation that was in the area.

In a press release, Richard Davies, co-author of a journal article in Marine and Petroleum Geology addressing the volcano, stated, “The disaster was caused by pulling the drill string and drill bit out of the hole while the hole was unstable; . . . this triggered a very large ‘kick’ in the well, where there is a large influx of water and gas from surrounding rock formations that could not be controlled.”  This kick, Davies argues resulted in fracturing rock in the area, which opened up routes for the pressurized mud to make its way to the surface.  These findings, as well as those that supported it by other scientists led the company conducting the drilling, PT Lapindo Brantas, to be held responsible for the volcano, and as such required to compensate the thousands of victims affected by the mud flows.  Additionally, thirteen Lapindo Brantas' executives and engineers face charges of violating Indonesian laws.

Research as to the causes of the volcano, however, is still ongoing, and the latest study, this time by a team of Russian geologists sanctioned by both the Russian and Indonesian governments, has gone back to the idea that it was earthquakes that caused the volcano eruption. The Russian scientists argue that if drilling had been the cause, an eruption should have taken place up the well, and not several hundred meters away as did happen.

It is unknown at this time if this study will have any political or legal repercussions regarding the ongoing cases against Lapindo Brantas, but it is certain it will lead to further scientific debate as to whether the volcano was the result of man or mother nature.