Thursday 9 August 2012

Earthquake northeast of Perth, Australia.

Slightly after 2.30 pm local time (slightly after 4.30 am, GMT) on Thursday 9 August 2012, Geoscience Australia recorded an Earthquake slightly over 200 km northeast of Perth, the capitol of Western Australia, measuring 2.7 on the Richter Scale, and at a depth to shallow to be measured. This is to small to have caused any serious damage of casualties, but is large enough that it may have been felt by people in the area.

The location of the 9 August 2012 quake. Google Maps.

Despite being a long way from any active plate margins, Western Australia is quite prone to Earthquakes, particularly in a zone referred to as the South West Seismic Zone. The cause of these quakes is unclear; the area exists within an area of Archaean Shield known as the Yilgarn Block, which is thought to be between 2.94 and 2.63 billion years old, and which has no internal structures that seem to be related to the quakes.

The South West Seismic Zone (pink). University of Western Australia.

Witness accounts of Earthquakes help geologists build up a picture of the movements associated with these events, and the buried structures that cause them. If you felt this quake you can report it here.

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