Mud volcanoes are formations created by the geological emission of liquids and gases. They are frequently associated with earthquake zones, and when they erupt, they release an often acidic slurry as well as methane and other hydrocarbon gases. Some mud volcanoes also spew flames when they erupt, though the volcanoes themselves tend to be relatively cool. A 2006 drilling accident in Indonesia created a mud volcano that inundated a number of villages and displaced how many people? Discuss