Tennant Creek shakes again
Tennant Creek residents were sent to bed last night with a shake as a magnitude 4.2 earthquake hit approximately 30 kilometres southwest of the township.
The earthquake occurred at 9:09pm (local time) 18 July 2013, with residents reporting rattling walls, rumbling sounds, strong shaking for up to 20 seconds and effects likened to 'a wave going through the house'. No damage was reported.
Senior Seismologist Dr Jonathan Bathgate said the area has a known seismic history, and is identified as having high seismic hazard.
This is the fourth earthquake above magnitude 4 recorded in the past 10 years, and the 22nd of that size or larger over the past 20 years. On average, Tennant Creek experiences two or three events above magnitude 3 each year, the most recent being a magnitude 3.7 in March 2013.
"Tennant Creek is the only place in Australia's recorded history to experience three powerful earthquakes - incredibly all in one day", said Dr Bathgate
The series of earthquakes occurred on 22 January 1988 measuring magnitude 6.3, 6.4 and 6.7. The earthquakes produced large ground ruptures and a 35km long fault scarp with up to two metres vertical displacement, causing structural damage and severe warping of a major natural gas pipeline.
Foreshocks started a year before the three large earthquakes, and thousands of aftershock followed over a number of years.
"All of these earthquakes are located in the same area as the three large events recorded in 1988", said Dr Bathgate.