Eleven earthquakes in the space of seven days may seem like a lot, but it has become the norm for the small West Australian town of Gnowangerup – although the cause of the tremors remains a mystery.
Gnowangerup has recorded almost 200 earthquakes since the start of 2026, most localised to an area about 10 kilometres to the north-east of the town near several farms.
Geoscience Australia chief seismologist Phil Cummins has been paying close attention to the seismic activity in the region.
“In January of this year, there was magnitude 2.2, that occurred towards the tail end of the month,” he said.
“February, March and even in April, there have been, I think on average, about three per day.
“And that means that some days there’s one, sometimes there are none, or some days there might be a dozen or more earthquakes happening.
“I’ve counted, there’s about 197, and they’re all within about 10 kilometres of each other.”
The regularity of the tremors prompted the local shire to hold a community meeting on Wednesday for residents to learn more about the seismic activity near the town.
It follows a significant magnitude-5 earthquake in the area back in 2023 which lasted about 30 seconds and caused damage to several homes.
Shire of Gnowangerup president Kate O’Keeffe said people who lived on those farms were feeling them and hearing them regularly.
“It was important to get some information first-hand, even though a lot of the answers were, ‘we don’t really know’,” she said.
“It’s still good to know that shire has been proactive, and we’re working with DFES, and they discussed what we need to do in case of a serious earthquake event, with regard to, you know, debunking the myth that it’s safe to stand under a door frame.
“But it is also reassuring to know that there are five seismometers in the area, and they’re continually monitoring, continually researching and continually learning about what’s happening, and they’ll share information as it comes to hand.”
Cummins said the cause of the recent tremors remained relatively unknown.
“There are a number of hypotheses, but it’s a bit of a mystery, particularly since the crust in south-west Australia is very old,” he said.
“One [reason] might be fluid. There’s migration of fluids in the Earth’s crust that are changing the stability of the faults as the fluid sort of flows through at depth in the Earth’s crust. I think that’s the most like the explanation.
“The Geological Survey of Western Australia has put in a few stations right near Gnowangerup and those will give us much higher precision on the location of the hypocentres.”
Cummins believes the recent seismic activity is a swarm – a sequence of small to moderate earthquakes occurring in a specific area over a short period without a single, dominant “main shock”.
O’Keeffe said despite the regularity of the earthquakes in the region, there had been no significant damage from the latest tremors.
“There was certainly some serious damage done to a couple of homes in 2023 but no at this point, it’s just rattling and shaking,” she said.
Due to the localised epicentre of the earthquakes, O’Keefe said she was yet to feel any of the seismic activity at her property to the south-east of town.
“Whereas we’ve got neighbours that have further south, sort of on the same line from where the epicentre is, who have felt them,” she said.
“So I haven’t felt one, but I know most people in town are discussing them.
“When I’m in town, people will be constantly asking, ‘Did you feel that earthquake at 5am this morning?’ And no, nothing.”
While authorities continue to work out what the official cause of the earthquakes could possibly be, O’Keeffe said the local residents were continuing to live their lives as they always have.
“I guess it’s just a watch and see,” she said.
“Hopefully, we’ll be all good news from here on in. But it certainly doesn’t sound as though they’re slowing down. I think there was five on Tuesday.
“I’ve lived here for 30 years, and up until the one we had a couple of years ago, it was unheard of, but this is unprecedented in my time.”
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