Scientists trying to unravel the mystery of earthquakes will soon do their biggest drilling operation in this country yet.

A team including GNS Science, Victoria University, and Otago University, is attempting to drill down 1.3 kilometres into the Alpine Fault.

Associate Professor John Townend says it should not only give them a better understanding of the biggest earthquake hazard in the South Island, but also help international scientists understand the mechanics of large faults.