In 2025, Broken Hill—an isolated city in far-west New South Wales—experienced the most intense ground shaking. Residents endured horrifying vibrations that distorted the nature of their everyday existence. Broken Hill is a very live mining town, quite used to ground-borne vibration. This year has already been unprecedented, with Geoscience Australia recording seven earthquakes. Most importantly, the tremors have caused no injuries or deaths, which brings huge added comfort to citizens and scientists.
Earthquakes in the central and eastern U.S. tend to be more random and are caused by a broad range of geologic factors. Jonathan Griffin, a senior seismologist with the USGS, uncovers truly fascinating details about the old rocks of the region. Dating back 1.6 to 1.7 billion years, these rocks have been shaped by a complex array of geological forces over their extensive history. “The continent, as a whole, is kind of getting squeezed,” Griffin noted. So when tectonic activity releases energy, old faults and weaknesses in the earth are reactivated. The sudden release of this energy can trigger small to moderate earthquakes.
Mining Operations and Earthquake Activity
In Broken Hill, the daily mining operations include blasts at 6:45 AM and 6:45 PM. These activities mark the sonic and vibrational terrain of the place. Luckily for us, Griffin is here to assure us that there’s no clear link between the recent earthquakes and mining operations. “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 stated.
Invisible impact Griffin explained how mining can sometimes cause seismic activity in surrounding areas. Robust monitoring is key to establishing any potential causal links. This difference is important for local residents who might be rightfully alarmed by the potential safety impacts of a hardcore mining operation.
For local resident Michael Boland, saving cinema in Broken Hill has been his life’s work. It’s with his experiences from the earthquakes that I was most inspired by him. “They always feel different to the mine blasts; [they] have a rolling feeling, you feel them rolling through, whereas when the mine blasts it’s different,” said Boland. His knowledge is a testament to the community’s familiarity with their one-of-a-kind geological landscape.
Historical Context and Seismic Records
Geoscience Australia’s records of earthquakes within a 100-kilometre radius of Broken Hill’s city centre date back to 1966. Since the mid-1960s, Australia has experienced relatively large and damaging earthquakes that were detectable given the coverage by instrumental means. Despite Broken Hill’s recent uptick in seismic events, it has historically experienced fewer earthquakes compared to its closest regional centre, Dubbo.
The rapid increase in activity is a great interest to geologists and seismologists, who are still piecing together the causes of the uptick. Griffin is quick to point out that earthquakes do not occur on a set timetable. He thinks their frequency is more likely the result of underlying natural geological processes than anthropogenic ones.
