Blind thrust faults tend to predominate on the North Island's east coast from southern Wairarapa to East Cape. Some have been identified, but it is likely many remain undiscovered. There are many New Zealand communities located within 10km of an active fault. Scientists have identified more than 200 active faults, so it's fair to say that many parts of New Zealand could experience an earthquake with effects similar those experienced in Hawke's Bay in 1931. While it is not possible to say exactly where and when the next one will strike, monitoring with GPS technology can quantify the rate at which strain is building up in the earth's crust to a depth of 30km.
High strain tends to be a precursor to an earthquake.
Dr Cowan says in 1931 there was little appreciation of New Zealand's location on an active plate boundary and the implications this has for the size of frequency of earthquakes. New Zealand's earthquake activity is almost comparable to that of California. A major earthquake, no matter where it was located, would affect the whole of New Zealand society and economy.