An earthquake is the shaking of the ground caused by a sudden release of energy that occurs when rocks deep underground move along fault planes. Most earthquakes in the world happen around active tectonic plate margins. Australia sits in the middle of the Indo-Australian tectonic plate, despite this, earthquakes still happen in Australia. On average 100 magnitude 3 or above earthquakes are recorded each year and a magnitude 6 or above earthquake is expected every ten years.
Earthquakes can vary in strength and size (known as the earthquake’s magnitude), lasting anywhere from a couple of seconds to minutes, often followed by aftershocks that are just as strong or even stronger than the actual event itself.
Some earthquakes can trigger tsunamis, which are giant waves that can travel for hundreds of kilometres and cause even more damage.
While most earthquakes in Western Australia are relatively small and cause minor damage, significant earthquakes can happen and you should know what to do if one hits.
Did you know? 4,185 earthquakes were recorded in WA between 1 January 2013 and 31 December 2022. That’s over 410 earthquakes a year!
Earthquakes are one of the most dangerous natural disasters that can occur. Unlike most other natural disasters, earthquakes don’t happen at a particular time of year and they cannot be predicted or prevented.
During an earthquake, unsecured items in homes and buildings can cause injury or death and pose a serious risk to people and animals. Earthquakes can also cause significant structural damage to, or even destroy, buildings, roads, bridges and other critical infrastructure.
It is essential to be aware of the dangers of earthquakes and take steps to protect yourself and your property.
By understanding these risk factors, you can take appropriate and often simple measures to prepare for an earthquake and reduce your risks of such an event. Some possible areas of focus for earthquake preparedness at home might include securing furniture and objects that could fall or cause injury, having an emergency kit and plan in place, and ensuring that gas lines and other utilities are properly secured. By taking these steps and staying informed about earthquake risks, individuals can help protect themselves and their loved ones in the event of a seismic event.
WA has two of Australia’s most seismically active regions - the northwest of WA and the South West Seismic Zone. These areas are more likely to host future earthquakes. The two largest magnitude earthquakes recorded in these areas are the Lake Muir earthquake (2018) in the South West Seismic Zone, and the Broome Offshore earthquake (2019) in the northwest Seismic Zone.
The largest recorded earthquake south of Perth was a magnitude 5.3 earthquake sequence in Lake Muir which began on 16 September 2018.
Damage occurred to localised structures near the epicentre, and more than 700 aftershocks were recorded, including a magnitude of 4.6 on 13 October 2018 and a magnitude of 5.2 on 9 November 2018. These events were widely felt throughout the southwest of WA, including parts of the Perth metropolitan area.
On the 5th of January 2022, Arthur River experienced a magnitude 4.0 earthquake. This was the first quake of the Arthur River Earthquake Swarm. An earthquake swarm is a series of low-moderate magnitude events which have no clear main shock, and each event has its own aftershocks.
The Arthur River swarm has continued for more than 18 months. The largest event in this swarm was magnitude 4.8 which occurred a few days after the first quake. This and other events in this swarm have been felt across much of southwest WA, including Perth, Albany and Margaret River. Since it began there have been more than 700 Felt Reports from people who have experienced these events with reports of minor structural damage.
DFES works closely with Geoscience Australia, which operates the National Earthquake Alerts Centre. The Centre provides 24/7 earthquake detection, analysis, notification and advice.
If a significant earthquake has impacted the community, DFES will issue a warning on Emergency WA.
If you’ve been injured or you are in a life-threatening situation call 000 immediately. If your property has been damaged don’t wait, contact your local government or State Emergency Services to arrange for temporary repairs.
Earthquake Alert: An earthquake has occurred, and you need to brace for aftershocks.
Take Care: The immediate danger has passed but take care as buildings, roads, and utilities might be damaged.
If you have recently experienced an earthquake, you can report your earthquake experience to Geoscience Australia using the Felt Report. Earthquake effects may vary significantly over small distances due to changes in ground conditions, your building type, and what you were doing at the time. By reporting your individual experience, you are helping to inform emergency services about the earthquake impacts in your area.
It’s critical that you know how to access different information sources to stay up to date during an earthquake.
During mobile network outages, radio is often the most reliable source of information. It is essential to have a battery-powered radio or another device capable of receiving broadcasts on AM/FM frequencies to stay informed in such situations.
Call 13 DFES: 133 337
Listen to ABC local radio
Main Roads WA or call 138 138