Study finds Indonesia `mud volcano` collapsing

"Such sudden collapses could be the beginning of a caldera -- a large basin-shaped volcanic depression," the institute was quoted by AFP as saying in a statement, adding that the caldera could be as much as 146 metres deep.

"(Scientists) propose the subsidence is due to the weight of mud and collapse of rock strata due to the excavation of mud from beneath the surface," it said.

The volcano in Sidoarjo district has been spewing around 60 Olympic swimming pools of mud a day since erupting to life in May 2006 from a gas drilling hole, owned by oil and gas company Lapindo Brantas.

Drilling by Lapindo, owned by the family of billionaire welfare minister Aburizal Bakrie, has been blamed for causing the mud flow, but the company claims an earthquake in the city of Yogyakarta was to blame.

Twelve villages have been affected by the spreading mud and at least 36,000 people have been forced to flee their homes.

The mud volcano ...