The Fiordland earthquake of 10 August, 1993: a reconnaissance report covering tectonic setting, peak ground acceleration, and landslide damage

On 10 August, 1993, a M L 6.7 (M s 7.1, M w 7.0) earthquake occurred c. 10 km offshore of western Fiordland, New Zealand (45.2°S, 166.7°E). Its hypocentre is approximately 20 km deep which places it on, or close to, the interface between the subducted Australian plate and the overriding Pacific plate. The focal mechanism for the mainshock indicates reverse faulting on either a steep west-dipping, or shallow southeast-dipping plane. Analysis of a subset of the over 7,000 recorded aftershocks defines a shallow (c. 15°) southeast-dipping plane, roughly 25 km long and 15 km wide, that probably represents the rupture surface of the mainshock. The earthquake was strongly felt by fishermen offshore in the epicentral region. Onshore, there were no reports of damage to man-made structures