Major Quake, South Island, New Zealand

A major earthquake struck the South Island of New Zealand overnight. Latest estimates put the quake at magnitude 7.8 at the shallow depth of 12 km, onshore in Fiordland National Park.

Thursday 16th July 2009

A major earthquake of magnitude 7.8 struck 100 km south-west of Te Anau, 160 km north-west of Invercargill at 9:22 p.m. last night. The quake was located on-shore in the Fiordland National Park in New Zealand’s South Island at the shallow depth of 12 km according to GeoNet.

Initial estimates put the quake’s magnitude at between 6.6 and 8.2 and the Pacific Tsunami Warning Centre issued a bulletin for the event at 9:42 p.m. indicating that a magnitude 7.8 event had occurred off the western coast of the South Island, calculating arrival times for a possible sea wave.

As authorities analysed the event and finalised the magnitude and location, it emerged that a wave of 17 cm was recorded at Jackson Bay at 10:18 p.m. and an oceanic measurement in the Tasman Sea of 5 cm allowed the warning to be cancelled at 10:51 p.m.

The main earthquake was felt throughout the South Island and as far north as Hamilton and at various centres in the Bay of Plenty. At midnight, power was still out in some areas of the South Island near the earthquake epicentre, and damage has been reported from several centres in the southern part of the South Island.

A magnitude 6.1 aftershock was recorded at 9:41 p.m., shallower at 5 km, located 200 km west of Invercargill, according to GeoNet. This event had attracted more than 500 felt reports from the public by midnight, with damage being reported in Otago and Southland.

[Compiled from data provided by the U.S. Geological Survey and its contributing agencies; and the GeoNet project and its sponsors EQC, GNS Science and FRST.]

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