Question: How many earthquakes rock Australia each year?
When it comes to earthquakes, we often think of countries like Japan and New Zealand rather than Australia.
While Australia is less likely to experience damaging earthquakes compared to our neighbours, on average, Geoscience Australia locates more than 600 earthquakes in Australia each year.
The tectonic plate that Australia sits in the centre of is one of the fastest moving on Earth. It is moving northward at a rate of seven centimetres a year, colliding with tectonic plates to our north.
Some of the stress from these collisions is redirected to the centre of the plate, deforming the rocks beneath Australia. When the stress on the rocks becomes too great, the rocks will break (usually along a fault line) and move permanently – in other words, an earthquake
Based on data from the last half-century, on average, Australia experiences more than 80 earthquakes between magnitudes of 3.0 to 4.0 each year.
Australia is less likely to experience earthquakes above magnitude 4.0, averaging 17 earthquakes each year for magnitudes from 4.0 to 5.0, and three for magnitudes from 5.0 to 6.0.
Australia only experiences an earthquake of magnitude 6.0 or larger around every 10 years.
In May last year there was a magnitude 6.1 earthquake in Central Australia near the Petermann Ranges, which left a 20 kilometre-long scar in the landscape.
The last earthquake to be widely felt throughout the Canberra region was a magnitude 3.7 earthquake near Wee Jasper in April 2012.
Based in Canberra, Geoscience Australia monitors and analyses seismic data in real-time from more than 90 seismograph stations across the country and 300 stations from around the world.
If you're interested in learning more about where earthquakes occur in Australia, Geoscience Australia will be opening its doors for a day of family fun on Sunday, August 20 from 9am to 2pm. I will be giving a talk on earthquakes in Australia at 9.30am.
Not only will you be able to learn more about the important and surprising roles geoscience plays in everyday life, but you can participate in a range of hands-on activities such as panning for gold and building your own satellite.
Response by: Dr Trevor Allen, Geoscience Australia
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