Java Drilling Triggers Major Onshore Mud Volcano

The latest edition of Nature reports that oil and gas exploration company PT Lapindo Brantas may have triggered the eruption of a mud volcano on the island of Java on May 28 during drilling. According to Nature, mud has been spewing from the ground for the last three months at a rate of 50,000 cubic meters per day. Abnormally high temperatures (60C) and hydrogen sulphide gas released with the mud suggests that the volcano is connected to a deep volcanic, hydrothermal source located nearly 3 kilometers below the surface. Geologists suspect that drilling penetrated an over-pressured volume of liquified sediment, which buoyantly pushed its way up to the surface. Walhi reports that gas initially "sprayed 10 meters high from cracks in the ground ... followed by hot mud." The flow of mud has displaced over 9,000 residents from their homes to date. East Java Police seized the rig that triggered the release of mud and gas. Offshore mud volcanos are common in the Java area, which overlies a subduction zone, where water and sediments are carried deep beneath the islands. "According to many geological experts, the scale of this mud volcano is unprecedented -- at least on land," writes Nature.