Outback city rumbles through a record year of ground shaking
It is not unheard of for the ground to shake in Broken Hill, but what is unusual is the number of earthquakes recorded by Geoscience Australia this year.
A sudden shaking of the ground in Broken Hill is not out of the ordinary.
The city in far-west New South Wales is an active mining town, and the mines blast at 6:45am and 6:45pm every day.
Since the mid-1960s "instrumental coverage" has detected significant earthquakes across Australia.
Since then, Geoscience Australia has recorded between zero and three earthquakes a year within a 100-kilometre radius of the city's centre, ranging from a magnitude-1.5 in 1979 to a magnitude-4 in January this year.
But 2025 has been somewhat out of the ordinary with seven earthquakes recorded by Geoscience Australia, the most in recorded history.
A random occurrence?
Geoscience Australia's records of earthquakes within a 100-kilometre radius of Broken Hill's city centre go back to 1966.
Senior seismologist Jonathan Griffin said there was no specific reason why Broken Hill had such a shaky year.
"The earthquakes generally occur randomly in time," Dr Griffin said.
"The continent, as a whole, is kind of getting squeezed."
In comparison with Dubbo, Broken Hill's closest regional centre in New South Wales, the Silver City has experienced fewer earthquakes, but there has been a sudden uptick in the past 12 months.
There does not seem to be a pattern in the magnitude of the earthquakes either.
Dr Griffin said one explanation could be in the age and movement of the rocks around Broken Hill.
"The rocks in the Broken Hill area are very old, 1.6–1.7 million years old. Those rocks have been through a lot, they've had a long life, and there's been periods of mountain building in that in the past around there … during which mineralisation has occurred," he said.
Jonathan Griffin says Broken Hill's busy year may be due to a multitude of factors. (Supplied: Geoscience Australia)
"What can happen, because we're squeezing the continent, some of those old faults, old weaknesses can pop off with smaller to moderate earthquakes from time to time."
Community members have also wondered if the city's long history of mining had anything to do with the movement of the ground, but Dr Griffin said this was unlikely.
"There is currently no evidence to suggest that the sequence of earthquakes that have occurred around Broken Hill this year is linked to mining,"
he said.
"In some cases, mining can induce earthquakes nearby, however, detailed monitoring is required to determine a link."
None of Broken Hill's earthquakes have resulted in injuries or deaths.