Earthquakes in Western Australia
Earthquakes have occurred in Western Australia on a regular basis throughout its geological history.
In 1849, the first earthquake following European settlement in WA was recorded. "On Saturday last, about a quarter past four o'clock a.m., several inhabitants of Perth were awoke by what they conceived to be a slight shock of an earthquake."
The largest earthquake affecting Western Australia in modern times was an offshore earthquake in 2019, occurring 202 km west of Broome at a magnitude of 6.6 causing minor damage in the town itself. The strongest earthquake with its epicentre on land is the magnitude 6.5 [1968 Meckering, Western Australia|Meckering earthquake|Meckering earthquake of 1968], which caused injuries to at least 17 people and extensive property damage; it was the best-known earthquake in Western Australia the late twentieth century. The previous largest earthquake documented occurred in 1941, at Meeberrie, in the Murchison region. Like many earthquakes it remained little known, due to its lack of impact on urban areas. Initially reported at magnitude 7.2–7.3 it was eventually revised down to 6.3 by Geoscience Australia in 2016. The Meckering quake was also revised down from 6.9 to 6.5 in the same year but in the process overtook the Meeberrie quake in strength.
Recording
Prior to scientific equipment being utilised to record earthquakes, newspaper reports appear to be the main source of historical information. Perth Observatory was the recording location from 1923 to 1959, when the Mundaring Geophysical Observatory was operated by the Bureau of Mineral Resources between March 1959 and April 2000. Subsequent to the closing of the Mundaring observatory, recording locations are more dispersed throughout the state.Significant earthquakes
Western Australia's largest recorded onshore earthquake to date was at the Wheatbelt township of Meckering, in October 1968. See the [|separate section] below.The Cadoux earthquake of 1979 with magnitude 6.1 caused surface rupturing, about long.
The Meckering, Calingiri and Cadoux earthquakes led to the identification of a zone of seismicity known as the South West seismic zone. This zone has now been significantly mapped and analysed and is the most active zone in Western Australia.
Exmouth 1906
The earthquake which occurred in 1906 about NW of Exmouth occurred before world earthquake monitoring had really developed. With an estimated magnitude of 7.5, it is probably the largest earthquake known to have occurred in the Australian region.Kalgoorlie 1917
On 28 August 1917, tremor was reported near midnight in Kalgoorlie, which resulted in an underground rock fall, killing one miner and injuring several others. Also in the 1990s further seismic activity required consideration of seismic activity.Meeberrie Station 1941
The second largest onshore earthquake to date in Western Australia was on 29 April 1941 at Meeberrie station at 01.35.39 am. It was initially reported with a magnitude of 7.3 but was revised to 6.3 in 2016.Yallingup 1946
On 20 April 1946 a magnitude 5.7 earthquake occurred near Yallingup at 9:13pm on 19 April 1946, which was felt at Kirup. A tremor was reported at 5:30am at Caves House Yallingup and at Busselton on 30 April, which is probably the same event, reported on the wrong date.Gabalong 1955
Gabalong, 30 August 1955, magnitude 5.8 Gabalong, a small community about east of Moora and NNE of Perth. The earthquake, at 9:52pm local time, was felt at MM VI at Yericoin and Miling, and MM V in Moora. It was felt in Perth at intensities between MM II and MM IV, and at Dongara at MM II.It was preceded by a magnitude 5.3 earthquake at the same location at 2:09pm on the same day. It was a SouthWest Seismic Zone earthquake, and because of the poor location capabilities at the time, may well be related to a series of earthquakes near Yericoin, which started with a magnitude 5.1 earthquake on 2 May 1949.
Busselton 1959
A magnitude 5.0 earthquake occurred at 12:07 GMT on 3 October at 34.5 degrees south, 114.5 degrees east. It was felt at Busselton, Yallingup, Margaret River, Bunbury, Cape Naturaliste and Cape Leeuwin.Near Brookton 1963
18 January 1963 at Nourning Spring, approximately NE of Brookton and approximately ESE of Perth. It was felt at Intensity VII at Nourning Springs, VI at Brookton, and MM II at Perth. It occurred at 1:49pm local time, and had a magnitude of 5.4, although it was given a magnitude of 4.9 originally. Many earthquake questionnaires were distributed for this event, and a good isoseismal map was prepared.Meckering 1968
On 14 October 1968 at 10:59am, an earthquake registering 6.9 on the Richter scale occurred east of Perth in Meckering, Western Australia. Injuring 20 people, causing over 2 million dollars in damage and felt in towns away, it is Western Australia's most destructive earthquake to date.The hypocentre occurred below the earth's surface in the Yandanooka/Cape Riche Lineamen region located east of Meckering. The fault trended on a north-south arc. Through strike-slip the eastern side of the arc shoved westward, upwards and in a southerly direction which left a distinct trench in its path. This intraplate earthquake is thought to be caused through east–west compressional force within the southwest seismic zone.
Lake Tobin 1970
24 March 1970, magnitude 6.7 near Lake Tobin in the Canning Basin, was the first in a location which had many more earthquakes over the following years. In all, there were three earthquakes of magnitude 6.0 or more, and 25 earthquakes of magnitude 5.0 or more, the last of which occurred on 13 February 1982.Calingiri 1970 & 1971
An earthquake struck the Wheatbelt town of Calingiri on 10 March 1970with a magnitude of 5.9. No buildings were damaged despite the epicentre being from the town and the surface being uplifted as much as.