The Indonesian mud volcano disaster which has displaced about 40,000 people was most likely caused by oil and gas drilling, not an earthquake, Australian researcher and academic Mark Tingay says.

In the August edition of Geology, Dr Tingay, who produced the research while at Adelaide University, writes that while mud volcanoes have been linked to earthquakes in the past, the earthquake some have blamed for this incident was too small and too far away to be responsible.

Santos is an 18 per cent shareholder in the drilling program, operated by Indonesian company Lapindo Brantas, which has been blamed for the mud eruption, which has been spewing mud since May 29, 2006.

Lapindo Brantas is part of a conglomerate owned by one of Indonesia’s richest families, of which People’s Welfare Minister Aburizal Bakrie is a member.

Dr Tingay told the Australian Earth Sciences Convention in Perth the mud eruption was averaging about 100,000 cubic metres of mud a day, and had displaced 40,000 people and was threatening another 60,000.

The amount of mud produced so far was enough to fill the Perth central business district to a height of 20m, or seven storeys.

A recent report in the Jakarta Post claims a government investigation had not yet reached a decision whether the disaster had natural or human-induced causes.

A decision in the South Jakarta District Court late last year, which is being appealed, cited natural causes as the most likely cause of the incident.

Dr Tingay and his fellow researchers believe the human-induced hypothesis is most likely.

“Despite the close temporal relation between the Yogyakarta earthquake and the . . . mud eruption, all of the known processes for remote triggering of fault reactivation and associated mud volcanism are implausible,” he writes in Geology.

“Analysis of the static and dynamic stress changes resulting from this Yogyakarta earthquake suggests that this earthquake was at least an order of magnitude too small to have triggered the . . . mud eruption.

“We suggest that no viable mechanism is yet known by which the Yogyakarta earthquake could have triggered the mud flow and that a drilling accident in the Banjar Panji-1 well, combined with unsafe drilling practices, was the most likely triggering mechanism.”

A recent investor presentation stated that Santos has made a $US79 million ($82.4 million) provision on its books for the disaster.

Santos spokesman Matthew Doman said the company did not comment on the cause of the incident.

CAMERON ENGLAND (AdelaideNow)