The Sidoarjo mud flow or Lapindo mud (informally abbreviated as Lusi, a contraction of Lumpur Sidoarjo wherein lumpur is the Indonesian word for mud) is the result of an erupting mud volcano in the subdistrict of Porong, Sidoarjo in East Java, Indonesia that has been in eruption since May 2006. It is the biggest mud volcano in the world; responsibility for it was credited to the blowout of a natural gas well drilled by PT Lapindo Brantas, although some scientists and company officials contend it was caused by a distant earthquake.