New Zealand’s Earthquake Commission (EQC) is funding research that promises better models to predict future multi-fault earthquakes.

Researchers at the University of Canterbury are trying to pinpoint where faults might set each other off, creating a major multi-fault earthquake, and to estimate what the maximum magnitude could be.

Lead researcher Tim Stahl says that up until now, criteria for multi-fault earthquakes have been considered as black and white thresholds.

His research is introducing “fuzzy logic,” giving a range of scenarios of what could happen. Testing the computer modelling against real data is a critical part of the project.

“We want to be able to understand how all these factors might combine to make some rupture scenarios more likely than others,” he said. “Ultimately the question we’re asking is, what is the maximum size earthquake we could have in a particular location?

“We really need to get a better idea of where this could happen and the impact it could create on the ground surface, on infrastructure like water and electricity, and on buildings.”

Earthquakes that rupture across multiple faults affect a bigger area and add to the amount of energy released, creating stronger quakes.

The 2016 Kaikōura quake was the most complex multi-fault earthquake ever recorded, while other recent earthquakes have also involved more than one fault.

Mr Stahl says the Kaikōura quake’s first fault was followed by movement in around 20 other faults, which combined to be around 16 times stronger than the original fault alone.

The New Zealand research will also take into account how its specific rock types behave under seismic stress and what happens with faults that have been labelled ‘inactive’.