Strong Quake, Central New Zealand

A strong, shallow earthquake struck central New Zealand at 2:31 this afternoon, New Zealand time.

Friday, 16th August 2013

A magnitude 6.6 earthquake struck the central part of New Zealand at 2:31 this afternoon. The quake was centred onshore, 10 km south-east of the town of Seddon in the county of Marlborough at the northern part of the South Island, according to GeoNet. They report that the quake was 8 km deep.

The United States Geological Survey reports the event as magnitude 6.5, located 29 km south-south-east of Blenheim, 80 km south-west of Wellington, at a depth of 10 km.

The Pacific Tsunami Warning Centre, which issued one bulletin for the event, reported the quake as magnitude 6.8 at a depth of 10 km. It noted that a widespread tsunami threat did not exist based on historical data.

Geoscience Australia reported the earthquake as magnitude 6.8 at a depth of 5 km. It noted that the quake would have caused damage up to 80 km from the epicentre, and would have been felt up to 1,000 km away.

The main quake was quickly followed by several strongly-felt aftershocks of magnitude five, overloading New Zealand’s commercially-funded geological reporting website, GeoNet. It is not clear how many magnitude 5 events have been felt in the area, but 7 were reported by GeoNet between 2:54 p.m. and 3:51 p.m. Alarmingly, GeoNet’s automated reporting system, which went live last year, reported earthquakes radiating out from the centre of activity, with events of magnitude 5.5 at Waverley (Taranaki) at 3:52 p.m., magnitude 4.4 near Levin (Horowhenua) at 3:27 p.m. and magnitude 4.9 near Taihape (central North Island) at 3:10 p.m. It is presumed that GeoNet, which has admitted to these analysis errors following recent significant earthquakes, has now eliminated these apparent errors from its database.

These events were reported as workers tried to head home from New Zealand’s capital city by foot or hitchhiking because the city’s commuter rail network was shut down by the quakes at the end of the working week, and alternative public transport was formally announced as “unavailable.”

Eight hours after the event, GeoNet’s website offers a brief summary of the main earthquake, and suggests following a link to a private media organisation called “Stuff” for more information. Analysis of the relevance of today’s earthquake sequence following the magnitude 6.5 event of the 21st of July and its damaging aftershocks is conspicuously absent.

[Compiled from data supplied by GeoNet, the United States Geological Survey, the Pacific Tsunami Warning Centre, and Geoscience Australia.]

One Response to “Strong Quake, Central New Zealand”

  1. Lizzie from Gizzie says:

    I tried to report the quake, but couldn’t get through, and I see later that they didn’t have any reports from Gisborne, so I guess others couldn’t get through either. BUT felt it, I did, was quite strong here and the rocking went on for some time. I knew someone had copped it!

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