The Institute was continually upgrading its seismic model of Wellington and an important part of that process was quantifying the potential hazard from all known faults. The major faults in the Wellington region have been known since early this century. They are the Wellington fault, the Wairarapa fault to the east, the Ohariu fault to the west, and the Gully fault which runs between Cape Terawhiti and Pukerua Bay. All are capable of producing an earthquake of magnitude 7.5, or greater. There are about 30 major faults in New Zealand.
Slip rates vary significantly.