Washington, Oct 31 : Petroleum geologists from around the globe have concluded that the east Java mud volcano was triggered by drilling of a nearby gas exploration well, not by an earthquake.
Lusi, the volcano in question, started to erupt in East Java, Indonesia, on May 29th 2006, and is still spewing huge volumes of boiling mud over the surrounding area. It has displaced around 30,000 people from their homes and swamped 12 villages.
The cause of Lusi was recently considered at a debate at an International conference in Cape Town, South Africa, which concluded with a vote between 74 world-leading petroleum scientists who considered the evidence presented by four experts in the field.
Some 42 scientists voted that gas exploration well, Banjar-Panji-1, which was being drilled by oil and gas company called Lapindo Brantas, was the cause.
Only 3 scientists voted for the alternative explanation - that the Yogyakarta earthquake two days before the eruption, whose epicentre was 280km from the mud volcano, was the cause.
Some 16 scientists voted that the evidence was inconclusive and 13 that a combination of earthquake and drilling were the cause.
The vote, taken at the American Association of Petroleum Geologists Conference in South Africa, follows months of scientific investigation and analysis published by some of the world's leading experts in their field.
The Key reasons supporting drilling rather than the earthquake as the cause for the volcanic eruption are: the earthquake was too small and too far away to have had a role, and, the well was being drilled at the same time and only 150 m from the volcano site.
Also, the well took a huge influx of fluid the day before the eruption, resulting in pressures that the well could not tolerate, and, the pressure measured in the well after the influx provides strong evidence that the well was leaking and even evidence for the initial eruption at the surface.
"I remain convinced that drilling was the cause of the mud volcano. The opinion of the international scientists at the event in South Africa adds further weight to my conviction and the conclusions of many other leading scientists who have studied Lusi," according to geologist Professor Richard Davies of Durham University, UK.
According to Susila Lusiaga, a drilling engineer and part of the Indonesian police investigation team, "There is no question, the pressures in the well went way beyond what it could tolerate - and it triggered the mud volcano."