Tennant Creek, NT
MS 6.3, MS 6.5 and MS 6.7
Fri, 1988 January 22

The Tennant Creek earthquake sequence in the Northern Territory began with an event of magnitude ML 5.4 on 1987 January 8. Aftershocks then continued throughout 1987.

A little over a year later, on 1988 January 22, three large earthquakes occurred, with magnitudes MS 6.3 at 10:06 am CST, MS 6.5 at 01:27 pm CST and MS 6.7 at 09:35 pm CST, and many smaller aftershocks.

The earthquakes were strongly felt in Tennant Creek, walls were cracked in well constructed buildings, objects fell from shelves and furniture was shifted. There were no serious injuries, but the strong shaking from the main events and the prolonged aftershocks badly frightened many residents.

The three main events were felt in Darwin, and the largest was felt as far as Cairns in northern Queensland and in high rise buildings in Perth and Adelaide. The epicentres were in the desert about 40 km southwest of the town, so total damage was limited to about A$1.2 million (1990 values), mainly to a damaged high pressure gas pipeline from Alice Springs to Darwin.

The earthquakes produced a surface rupture trending east-west about 35 km long, with the south block thrust over the north block by up to one metre vertically and about 2 metres horizontally. The events were the result of north-south compression.

The SRC and AGSO installed an aftershock network, and many hundreds of events were recorded. Activity in the area continues at a high level ten years later.

The Tennant Creek area had no history of earthquake activity before 1987.