By Marci Wills, Feb 19, 2010
When I first heard the highly scientific term “mud volcano” I thought it sounded awfully lame, but those in Indonesia would likely argue otherwise. On May 29, 2006, a mass of boiling mud unexpectedly erupted from beneath the densely populated Sidoarjo district of Java. The “Lusi mud volcano” (a conjunction of Lumpur, the Indonesian word for mud, and Sidoarjo) killed 13 people in 2006 due to ruptured gas pipelines and displaced an estimated 30,000 more. I vaguely remember hearing about this back when I was graduating from high school. So I was rather shocked when I learned this week, in my senior year of college, that the Lusi eruption hasn’t stopped!
Nearly four years later, the mud volcano continues to ooze at an alarming rate of 160,000 cubic meters of 100°C mud every day (enough to fill 50 Olypmic-sized swimming pools!) It covers an area of 7 square kilometers (~3 square miles) up to 20 meters (65 feet) deep. The muck has defeated all efforts to thwart it, including dams, levees, drainage channels, and even attempts at plugging the center with large concrete balls. The volcano shows no signs of slowing, much less stopping, and researchers estimate it could continue to erupt for several decades. Naturally, a lot of people want to know why it happened.
Lusi is one of the largest examples of about 700 recognized mud volcanoes throughout the world. (Although the number varies depending on definition. Do you call a 1 meter high mound that seeps every so often a mud volcano too?) In addition to Indonesia, they are concentrated in Azerbaijan, Turkmenistan and the South Caspian Sea, often in regions associated with petroleum deposits. Mud volcanoes form when a large volume of water, mud, clay and gas becomes trapped underground. These liquid chambers can sit under very high pressures for millions of years until until they suddenly find a pathway to the surface.
Two possible triggers have been identified for the Lusi mud volcano; a magnitude 6.3 earthquake which occurred 2 days earlier on May 27th, 2006, 250 km away in Yogyakarta, and a gas exploration well located only 150 m from the eruption. The drilling firm Lapindo Brantas has desperately refuted claims that poor drilling practices in their well lead to the eruption, while many other independent scientists try to prove them wrong. The resulting debate has seemingly quadrupled research on mud volcanoes, while delaying the establishment of liability and compensation to thousands of people affected.
The dispute culminated just this last month (February, 2010) in two studies from the opposing sides. Nurrochmat Sawolo, senior drilling advisor to Lapindo Brantas, and his colleagues asserted their claims in the journal Marine and Petroleum Geology, blaming the Yogyakarta earthquake for the eruption. An international team of scientists from the UK, USA, Australia and Indonesia, lead by Michael Davies of the Durham Energy Institute, responded with a paper in the same journal, providing the most definitive evidence yet that the well was the source of the drilling.
The Davies team found that the Yogyakarta earthquake was too small and distant to have triggered the Lusi mud volcano; the forces felt from the earthquake 250 km away in Sidoarjo were less than those felt there normally simply by weather and the tides. They also cite an on-site daily drilling report which states that Lapindo Brantas successfully pumped drilling mud back into the well immediately after the eruption to slow it. “The observation that pumping mud into the hole caused a reduction in eruption rate indicates a direct link between the wellbore and the eruption”, Davies says.
Such definitive evidence that the well caused the Lusi volcano is expected by many to resolve the debate, but what will legally come of the disaster remains to be determined. Either way, Lusi will surely continue to make its own muddy statement for years to come.
Sawolo, N., Sutriono, E., Istadi, B.P., and Darmoyo, A.B., 2009, The LUSI mud volcano triggering controversy: was it caused by drilling?: Journal of Marine and Petroleum Geology, v. 26, p. 1766-1784.
Mazzini, A., Svensen, H., Akhmanov, G.G., Aloisi, G., Planke, S., Malthe-Sørenssen, A., and Istadi, B.P., 2007, Triggering and dynamic evolution of the LUSI mud volcano, Indonesia: Earth and Planetary Science Letters, v. 261, p. 375-388.