New Zealand's Earthquake Monitoring Service has issued a warning after the quake.
"This fault system has the potential for larger events and we would like to make sure that you are prepared for a large earthquake at all times," New Zealand Geonet said.
No damage has been reported so far.
According to the Straits Times, the Alpine Fault runs 600km along the entire spine of New Zealand's Southern Alps and has a record of rupturing every 300 years.
Last year, scientists predicted that a large quake could hit New Zealand's South Island and reshape the entire region, cutting off more than 10,000 people.