Authorities in East Java have raised the alert level for the mudflow spewing from an underground volcano in Sidoarjo after nearby dikes nearly failed.
The mudflow has destroyed hundreds of homes, swamped 720 hectares of land and displaced more than 11,000 people since it began erupting in late May 2006.
“The situation is alarming,” said Achmad Khusaeri, a spokesman for the Sidoarjo Mudflow Mitigation Agency (BPLS), adding that the underground volcano had begun to erupt again after lying virtually dormant for years.
Good article on this on Wikipedia.
The Sidoarjo mud flow or Lapindo mud, also informally abbreviated as Lusi, a contraction of Lumpur Sidoarjo (lumpur is the Indonesian word for mud), is a mud volcano in the subdistrict of Porong, Sidoarjo in East Java, Indonesia that has been in eruption since May 2006. This biggest mud volcano in the world was created by the blowout of a natural gas well drilled by PT Lapindo Brantas, although company officials contend that it was caused by a distant earthquake.
At its peak Lusi was spewing up to 180,000 m³ of mud per day. At mid August 2011, mud discharged were 10,000 cubic meters per day with 15 bubbles around the gush point, declined a lot from a year ago when mud discharged 100,000 cubic meters per day with 320 bubbles. It is expected that the flow will continue for the next 25 to 30 years. Although the Sidoarjo mud flow has been contained by levees since November 2008, resultant flooding regularly disrupts local highways and villages. Further breakouts of mud are still possible.