VK is the amateur callsign prefix for Australia, 2 is for the state of New South Wales, 3 for Victoria and so on. So the callsign of any radio amateur whose station (QTH) is located in NSW would begin with VK2.
Australia covers an enormous area almost the size of the US or Europe and even the state of NSW is huge so seismic activity varies widely from place to place. Generally though Australia is very lucky in that its seismic activity is very low—unlike New Zealand which is the next landmass in the Pacific which is very high.
In recent years the only significant earthquake in NSW was in the coastal city of Newcastle in 1989 and over a dozen people were killed. When I was a kid decades ago I lived in the Blue Mountains of NSW which is about 120 miles from Newcastle and I experiencd an earthquake and I thought the house would collapse but luckily it did not (I was in bed and when it started I had difficulty walking across my bedroom the floor shook so much). It's the earthquake in the list in the link below marked 'Robertson and Bowral' with a magnitude of 5.5.
