This article was originally conversation.
On May 29, 2006, a rice farmer in Indonesia’s Sidoarjo province awoke to a strange sight. It exploded overnight and was spewing steam..
Over the next few weeks, water, boiling mud and natural gas were added to the mixture. As the eruption becomes more intense, Mud began to spread over the fieldAlarmed residents evacuated and waited safely for the eruption.
except it didn’t stopWeeks passed and the spreading mud engulfed the entire village. In a desperate race against time, the Indonesian government has started building dikes to contain the mud and stop its spread. When the mud overtopped these dykes, they built new dykes behind the first set. The government eventually succeeded in halting the progress of the mud, but the currents wiped out dozens of villages, displaced 60,000 people.
Why did the Earth suddenly start spewing out so much mud?
Introduction to mud volcanoes
The Lusi structure – a contraction of Lumpur Sidoarjo, which means “mud of Sidoarjo” – is an example of a geological feature. known as mud volcanoesThey form when a combination of mud, liquid, and gas erupts at the surface of the earth. The term “volcano” is borrowed from the familiar world of igneous volcanoes, where lava appears on the surface. i have been studying These fascinating structures of subsurface seismic data over the past five years are unmatched in watching active eruptions.
In the case of mud volcanoes, mud often bubbles to the surface rather quietly. But sometimes eruptions are very violent. Additionally, most of the gas coming out of mud volcanoes is methane, which is highly flammable. This gas can ignite and cause spectacular fire-like eruptions.
Mud volcanoes are largely unknown in North America, but are more common not only in Indonesia, but also in other parts of the world such as Azerbaijan, Trinidad, Italy and Japan.
They form when fluids and gases that build up under pressure inside the Earth find escape routes to the surface through a network of fissures. Fluid moves up these fissures, carrying mud and creating mud volcanoes as it escapes.
The idea is similar to a car tire containing compressed air. As long as the tire is intact, the air stays safely inside. But when the air gets out, it starts escaping. Sometimes the air escapes as a slow leak, sometimes it blows.
When subterranean liquids cannot escape under the weight of sediment above, overpressure within the earth builds.some of this liquid trapped in sediment when deposited.other fluids move from deeper sedimentsalthough there may still be others Generated in situ by chemical reaction in sediments. One important type of chemical reaction produces oil and natural gas. Finally, the fluid can become over-pressurized. pressed by tectonic forces during orogenic.
Overpressure is commonly encountered and usually planned during oil and gas drilling. The primary method of dealing with overpressure is to fill the well with dense drilling mud that is heavy enough to contain the overpressure.
If a well is drilled with insufficient mud weight, the over-pressurized fluid can push up the well and explode at the surface, leading to spectacular eruptions.Famous examples of blowouts include the 1901 spindle top gasher Texas and recent 2010 Deepwater Horizon Disaster in the Gulf of Mexico. In that case, it was oil, not mud, that spewed out of the well.
Mud volcanoes are not only fascinating in their own right, they also serve as windows for scientists. deep earth conditionsBecause mud volcanoes can contain material from as deep as six miles (10 kilometers) below the surface, their chemistry and temperature can provide useful insights into deep Earth processes not otherwise available. increase.
For example, analysis of mud spewing from Rusi showed that water Heated in underground magma chambers related to nearby Arjuno Weriran Volcanic ComplexAll mud volcanoes reveal details about what’s going on underground, allowing scientists to build a more comprehensive 3D view of what’s going on inside the Earth.
Lucy’s mud is still gushing
Today, more than 16 years after the eruption began, the Rusi structure in Indonesia continues to erupt, albeit at a much slower rate.that mud Covers a total area of approximately 2.7 square miles (7 square kilometers), with more than 1,300 soccer fields, contained behind a series of levees built to heights of 100 feet (30 meters).
Equally interesting as the effort to stem the quagmire is the legal battle aimed at holding accountability for the disaster. The first rupture occurred approximately 650 feet (200 meters) from an actively drilling gas exploration well, widely publicized accusation of The oil company in charge of the well was at faultLapindo Brantas, the operator of the well, countered that it was a natural eruption caused by an earthquake that occurred a few days earlier.
those who believe in the gas caused the eruption experienced Ejection due to insufficient mud weight, but the eruption did not come all the way from the well to the surface. Instead, the fluid reached only halfway down the well, injected laterally into the crack, and erupted at the surface hundreds of meters away. As proof, these proponents point out that: Measurements made in wells during drillingAdditionally, they suggest that the quake was too far from the well to have any impact.
By contrast, proponents of earthquake triggers believe that the Rusi eruption Underground active hydrothermal systemSimilar to Old Faithful in Yellowstone National Park. They claim that such systems have a long history of being affected by very distant earthquakes, so the argument that Rusi was too far from earthquakes is invalid.
Furthermore, they suggest that pressure tests of the well conducted after the eruption began showed that the well was intact and not breached by fissures or leaking fluids. Consistent with this interpretation, there is no evidence that drilling mud emerged from the Rusi eruption.
2009, Supreme Court of Indonesia dismissed the lawsuit accused the company of negligence.In the same year, the police quit criminal investigation Lapindo Brantas and several of his employees, for lack of evidence.
Michael R. Hudec is a Senior Fellow at the University of Texas at Austin’s Office of Economic Geology. He is funded by the Institute for Applied Geodynamics, an oil industry-funded research consortium backed by more than 20 companies.