In May, 2006 hot, dark mud appeared from a fissure and eventually covered more than 10 square kilometers in Porong, eastern Java, Indonesia, displacing more than 30,000 people. The ongoing mud extrusion has also damaged or broken important transportation and communication infrastructure, displaced an oil pipeline, caused the closure of numerous factories, and impacted agricultural development.

The USGS was invited to lead a fact-finding visit to assess the ongoing geological, social, economic, and political issues associated with the mud extrusion.