Shaking up Australia's earthquake sizes
11 May 2016
As a result of a global project to more accurately measure historical earthquakes, Australia's list of largest recorded earthquakes has dramatically changed - placing Tennant Creek at the top of the table.
A magnitude 6.6 earthquake recorded near Tennant Creek in 1988 is now considered Australia's largest ever recorded earthquake. It was one of three very large earthquakes all occurring on 22 January 1988, followed by thousands of aftershocks felt throughout the Northern Territory.
Geoscience Australia has revised a number of Australia's most notorious earthquakes as part of an international effort to more accurately reflect the true size of historic earthquakes across the globe. One of the most significant changes from this project was to the 1941 Meeberrie earthquake, Western Australia - previously considered Australia's largest onshore earthquake.
The Meeberrie earthquake was originally recorded as a magnitude 7.2 based on personal accounts of those who felt its effects. Now, through an improved understanding of Australia's seismicity and by applying modern techniques to a vast database of international seismic events, the magnitude has been revised to 6.3.
"It's quite a common understanding amongst seismologists that this earthquake, and others of the time, may have been overestimated and are in fact considerably smaller than historically reported", said Spiro Spiliopoulos, Senior Seismologist at Geoscience Australia.
"There were minimal recordings of the Meeberrie earthquake given its remote location and the technology available in 1941. Seismologists at the time resorted to calculating the size of the earthquake primarily by deciphering entries in the local homestead owner's diary."
"There is still a lot to learn about intraplate seismic events such as the ones that occur on the Australian continent, and we are constantly seeking to improve our knowledge by participating in international projects such as this one", Spiro said.
You can explore Australia's earthquake history on the Geoscience Australia website, from events that occurred up to 70 000 years ago, through to the earthquakes that have affected Australian communities in recent years.