Source mechanisms and strong ground motion from the 1982 Wonnangatta and the 1966 Mount Hotham earthquakes

The Wonnangatta earthquake of 21 November 1982 took place about 190 km NE of Melbourne, It was felt throughout eastern Victoria and southeastern New South Wales and the radius of perceptibility was about 195 km. Because the earthquake occurred in the middle crust (∼17 km) and the epicentral area was uninhabited, no damage could definitely be attributed to the earthquake and the highest reported intensity was VI on the Modified Mercalli Scale. The main earthquake was followed by 29 aftershocks that were large enough to be located and helped define the causative fault. The focal mechanism of the main earthquake was well constrained and the major double couple had a strike of 357°, a dip of 52° and a slip angle of 52°. This mechanism is consistent with horizontal compressive stresses acting NW‐SE in the crust, as observed from other earthquakes in the region. The magnitudes of the main earthquake were estimated to be 3.8 Ms, 4.8 mb and 5.4 ML and the seismic moment of about 6.3 x 1015 N m or 1.0 x 1017 N m, ...