A small earthquake recorded near Cessnock on Tuesday was the eighth in the Hunter Region in the past month.
The 2.6-magnitude quake was recorded at 10.05pm on September 20 in Heaton State Forest at Quorrobolong (about 15 kilometres south-east of Cessnock.
Three small quakes (measuring between 2.1 and 2.4 on the Richter scale) were reported near Gresford shortly after 3am on August 27.
Four quakes were reported felt near Muswellbrook last week – a 2.3 at 11.19pm on September 15, and three the following morning between 8.44am and 8.47am.
Geoscience Australia duty seismologist Daniel Connolly said the probability and patterns of earthquakes is impossible to predict, but a series of small quakes is not at all uncommon.
Mr Connolly said it was hard to draw a conclusion as to whether the quakes were related to mining activity.
Mr Connolly said information from the public can assist Geoscience Australia, so if you think you have felt an earthquake, go to ga.gov.au and make a report.