Completeness of the Paleoseismic Active‐Fault Record in New Zealand

Abstract

ABSTRACT Recent damaging earthquakes in New Zealand ruptured faults that were not known to be active. We analyzed New Zealand historical moderate‐to‐great magnitude earthquakes since 1845 ( M w 6–8.2) to estimate the level of completeness of earthquake fault sources in the National Seismic Hazard Model (NSHM) and the paleoseismic record. Our analysis assumes that the historical earthquakes are representative of the paleoseismic record and, due to the small number of events (45 M w ≥6), is qualitative. We find that about half of all historical earthquakes M w ≥7.0 ruptured faults that, based on today’s state of knowledge of active‐fault locations, would not have been identified as active prior to the event. The majority of historical events on faults previously not identified as active were M w