South Australia earthquake: Mid north's biggest jolt in 20 years ABC Online An earthquake which jolted the mid-north of South Australia last night was the region's biggest in 20 years, Geoscience Australia says. The magnitude 4.7 quake rattled the area about 60 kilometres east of Peterborough just before 7:30pm ACST. Geoscience ... South Australia's north rocked by 4.7-magnitude earthquake Earthquake strikes in regional SA |