What kind of plate boundary occurred in the 1989 Newcastle earthquake?

1 Answer
Aug 6, 2018

The suspicion is that the earthquake was not caused by a plate boundary movement but by a collapse in the earth due to coal mining.

Explanation:

The earthquake occurred in an area where there had been substantial coal mining. There are no plate boundaries near the location of the earthquake. The suspicion is that a collapse of multiply old mining shafts one on top of the other caused the earthquake.