The epicentre of two earthquakes, recorded 6.5 hours apart on July 7, was Cape Jervis at the tip of the Fleurieu Peninsula.
According to Geoscience Australia, the first earthquake was felt at 5.12pm (6.42am UTC) and measured 2.8 magnitude.
It was 10km deep and Geoscience Australia received 12 'felt reports'.
The second earthquake hit at 11.47pm (1.17pm UTC), with 29 'felt reports' recorded.
This one was slightly bigger at 2.9 magnitude, but was also measured at 10km deep.