Residents were woken by an earthquake that hit Whyalla early on Thursday.
The tremor north of Cowell sent shockwaves to the steel city about 2.30am.
Geoscience Australia said 13 reports of the tremor had been received from Whyalla.
The tremor was magnitude 3.7 on the Richter scale at a depth of 10 kilometres.
It was felt as far away as Kadina on Yorke Peninsula.
A Geoscience spokesman at the National Earthquake Alerts Centre in Canberra said that In the past 100 years there had been more than 300 earthquakes in the region.
“Of these, about 50 were magnitude three-to-four so the earthquake on Thursday morning was not too out of the ordinary," he said.
“In terms of larger events, only nine have had a magnitude greater than four. And only one greater than five.
“They do seem to cluster onshore along the near coastal trip on the western side of Spencer Gulf.
“Cleve, to the southwest of Cowell, had a magnitude 3.7 in July.
“The biggest earthquake on record goes back to 1959. Mamblin, south of the Gawler Ranges and farther west of Whyalla, recorded a magnitude 5.1.
“In 1960, there was a sequence of several moderate earthquakes of magnitude 4.2 to 4.8 in the region between Cleve and Kimba.
“The latest tremor was nothing to worry about. These moderate events happen from time to time and are not predictable.”