No answer to bubbling river mystery

Scientists working on behalf of an energy company have failed to solve the mystery of a bubbling river in outback Queensland, despite a "considerable sum" already spent investigating the phenomenon.

After two years and a significant investment, coal seam gas company Origin has released its scientific report that is inconclusive on a cause for the strange scene in the Condamine River near Chinchilla, 290km west of Brisbane.

There are several theories behind the unexplained bubbling, but not one has been proven.

Coal seam gas itself cannot be scientifically ruled out – but Origin's report raised many other theories, The Courier-Mail reports.

The bubbling can be seen along a 5km stretch where coal seam gas is plentiful and is being actively extracted.

Some locals claim it has been happening for decades while others say they first noticed it soon after heavy flooding subsided a couple of years ago.

The recent report says the flood may have caused water stocks underground to be recharged.

There is also the possibility the gas is escaping natural routes like fractures, faults and springs.

Origin boss Ross Evans said the company would keep investigating until it found an answer.

"It's complex geology and gas has been naturally occurring in the shallow strata for some time," Mr Evans told the newspaper.

"The important thing is to put the monitoring in place."

Source: The Courier-Mail.