Report Blaming Quake Stokes Indonesia Volcano Row [
Date: 01-Aug-07
Country: NORWAY
Author: Alister Doyle, Environment Correspondent
Scientists say they may never find the exact trigger for the continuing eruption of noxious-smelling mud from the ground in East Java that has engulfed an area four times the size of Monaco and forced about 15,000 people to leave.
Indonesia's government has ordered energy group PT Lapindo Brantas to pay compensation to victims of the mud flow that began on May 29 last year, 200 metres from a Lapindo exploration well and two days after a distant earthquake.
Lapindo disputes that its drilling was the trigger.
"The available data supports the hypothesis that the initial activity ... was mainly triggered by the energy released by the 27th of May earthquake and not by the drilling," according to report by a team of scientists based in Norway, Russia, France and Indonesia.
The study, accepted for publication in the journal Earth and Planetary Science Letters, says the earthquake centred about 280 km (170 miles) away jolted faults under the island that ended up releasing pressure in deep rocks and spewed out the mud.
But another leading expert said he was not convinced.
"The earthquake was probably too small and too far away to have had a significant role," said Richard Davies, a professor at Durham University in England, who reckons Lapindo's drilling was probably to blame.
RIPPLES
Adriano Mazzini, an Italian mud volcano expert at the University of Oslo and an author of the new study, said earthquakes could have ripple effects thousands of kilometres away and with delays of days.
A quake in Alaska, for instance, had been linked to later seismic activity in Yellowstone National Park far to the southeast.
"There is a big geological fault in the region (in East Java) and the mud volcanoes are located along this fault," he told Reuters.
"We know the fault was reactivated by the earthquake," he said, pointing to a buckling of railway lines nearby.
Davies said that a "subsurface blowout" in the drilling well was the probable cause, adding that Lapindo had tried to withdraw the drill-bit after problems deep in the well.
"The mud volcano was most probably caused by gas and/or water coming into the wellbore as they pulled the drill-bit out of the hole, which caused an increase in pressure in the wellbore and a fracturing of rock strata," he told Reuters.
He said he was working on a study with new evidence that Lapindo's well was probably the cause.
The mud volcano has been spewing out mud since the eruption despite schemes to halt the flow including dropping giant concrete balls into the crater. Mud volcanoes have been found in nations from Azerbaijan to Trinidad.
Lapindo has been ordered by the government to pay 3.8 trillion rupiah (US$412 million) to victims and to help halt the flow. Lapindo is indirectly controlled by PT Energi Mega Persada Tbk.
