US scientists warn a newly discovered fault in Arkansas could trigger a magnitude seven earthquake.The Arkansas Earthquake Centre says the fault is at least seven miles long and its epicentre is near a major natural gas pipeline. It believes the fault, which lies west of Marianna, is around 5,000 years old and will have caused at least one big tremor in its history.
Little Rock, the capital of Arkansas, would be at risk if there was a powerful quake despite being 100 miles southwest of the line.
