It's 6am now and I am in Brisbane [well, the Gold Coast]. I moved here about a month ago from Melbourne. However, I just finished working (on a contract website) and noticed my dad was online. So I said hi. Then he told me there was an earth tremor in Melbourne last night at around 9PM. He said that he was in front of his computer and then his monitor started shaking a little.
Now, I am from Melbourne. I am 33 years old, and not once in my life have I ever known Melbourne to experience Earth tremors. With the worst bushfires in history (in recent weeks), and now "earth tremors", it's probably lucky I moved out of there. What on earth is going on?
I just did a little research online and it seems that the earth tremor was 4.6 on the Richter scale, with the epicenter at Korumburra, about 90km southeast of Melbourne. There were many reports over a radius of around 100 KM.
Dad lives only 20 KM or so, west of Melbourne, and Korumburra is at least 130KM east Melbourne, so I guess that report isn't quite correct. It seems that the radius was at least 150KM (about 92 miles).
Korumburra - Google Maps