Wednesday, 24 January 2018

Yes, I felt that Earthquake too

Earthquakes are a bit infrequent in our part of the world. So, when one is big enough to feel happens there is usually much excitement.

While in my home office a few hours ago (1.30pm this afternoon) I felt a strange sensation and the roof of my studio shook. About 1 minute later, my wife came up from the house and asked if I had felt something, because the house shook for a moment. So, onto trusty Geoscience Australia Earthquakes page I went. Sure enough a substantial (by our standards) quake hit somewhere under the ground near Urunga.

I've put together a quick map which shows all the mapped major faults in the area (noting that most of them are actually inferred). I have overlain the last 24hrs worth of quakes to see if there is a correlation. There appears to be very little if any. But that is unsurprising given most faults have probably been inactive for millions of years. But I suppose interesting anyway. Note that the data had not been double checked by Geoscience Australia when I put this together.*
*Since posting the above, the earthquake epicentre has been updated to near Nambucca Heads the hypocentre being approximately 10km below Nambucca Heads.


  1. Thank you for providing a fault line map with the recent quakes overlaid. I was only just saying to my husband that I wish I could find a map of fault lines for that region so I could overlay the ga website map. Where does the Texas and Coffs Harbour orocline lie in relation to the maps and how far is the Demon Fault from the area?

    1. Hi Unknown,

      Glad that I could do something useful in this zone. It was a curiosity to me so I put it together and thought others might be interested too.

      With regards to the Demon Fault. This fault system is situated a little further (but not much) to the western side of the map. It is covered in much of that area by younger volcanics which obscure its location.

      The area portrayed in the map above is within the eastern most limb of the Orocline. The nearest hinge if the S-shaped Orocline is not too far further to the south-west. The Texas-Coffs Orocline is certainly the major encompassing structural element.