New research finds there's a high chance of the Alpine Fault rupturing in the next 50 years, with an earthquake measuring magnitude eight or higher.
The faultline - which runs up the spine of the South Island - has ruptured four times in the past 900 years, producing an quake of about magnitude eight each time.
Scientists had thought there was about a 30 percent likelihood of another quake this big by 2070 - but now they're saying that figure is 75 percent.
Dr Jamie Howarth is a senior lecturer in natural hazards at Victoria University and lead this research.
