Two earthquakes rattle New South Wales within hours
Magnitude 3.8 tremor in Orana shortly before 11 p.m. was followed by a shallow 3.7 quake near Muswellbrook at 2:22 a.m.; monitoring stations registered shaking as far away as Victoria
Two separate earthquakes shook communities across New South Wales within hours overnight, seismic monitoring stations recorded, leaving residents across the state unsettled.
The first event, measured at magnitude 3.8, struck the Orana region just before 11 p.m. on Monday at a depth of about 10 kilometres beneath the surface. Hours later, at 2:22 a.m. Tuesday, a second tremor measuring magnitude 3.7 occurred near Muswellbrook in the Upper Hunter; that event was much shallower, recorded at a depth of roughly 3 kilometres.
Seismological monitoring stations picked up the Orana tremor at distances extending to Victoria, indicating the first quake’s energy propagated across a broad area. The later Muswellbrook event, being closer to the surface, typically would produce stronger local shaking even at a slightly lower magnitude.
The back-to-back events occurred within a span of about three hours. Both were within the magnitude range that is commonly felt by people but rarely causes significant structural damage. Authorities and monitoring agencies continue to track seismic activity to determine whether there will be any related aftershocks.
Eastern Australia, including New South Wales, experiences occasional intraplate earthquakes — tremors that occur away from plate boundaries. Such quakes can be felt over wide areas because the older, colder crust in the region transmits seismic waves efficiently. Depth and local geology influence how strongly an event is experienced at the surface; shallower quakes, like the Muswellbrook event, often produce more pronounced shaking near their epicentres.
Emergency services did not immediately report widespread damage following the overnight events. Local residents described being woken by the shaking in some communities. Seismologists use data from a network of instruments to refine locations and magnitudes in the hours after events and to assess the likelihood of further activity.
Officials have advised people to follow standard safety guidance for earthquakes, including checking for damage to buildings and securing heavy items, and to report any structural concerns to local authorities. Monitoring of seismic activity across New South Wales will continue as agencies compile and analyse the data from both events.