BHP Billiton officials have announced that, beginning October 31, production at their Nickel West Leinster Perseverance underground mine in Australia was suspended following a significant seismic event. Technical and operational surveys, they added, determined sub-level operations are no longer safe.

Nickel West, however, will continue processing at Leinster, along with BHP’s other operations in Western Australia. Perseverance underground infrastructure maintenance, meanwhile, will continue ahead of a Q4 2013 impact assessment.

But although mining will resume at the nearby Rocky’s Reward open-cut mine as an alternative ore supply, BHP also announced a Leinster workforce reduction. Nonetheless, “as this change is implemented,” said Nickel West Asset President Paul Harvey, “we will continue to treat our people with the utmost care and respect.”