West Coast Earthquakes

Some West Coast residents were woken by a pair of undersea earthquakes this morning.

Sunday 28th June 2009

GeoNet reports a pair of earthquakes struck off the South Island’s West Coast this morning. The 6:32 a.m. quakes were of magnitude 5.0 and 4.8 at depths of 12km and 90 km. The larger event was located 100 km north-west of Ross, the other 90 km north-west (120 and 110 km west of Greymouth respectively).

An examination of GeoNet’s database shows the events timed 1 second apart, and further analysis may combine them as the same event, part of a shearing along a deep fault structure under the Tasman Sea.

Shaking from the events was felt along the West Coast from Westport to Fox Glacier and inland at Reefton, attracting 99 reports from the public by midday.

[Compiled from data provided by the GeoNet project and its sponsors EQC, GNS Science and FRST.]

One Response to “West Coast Earthquakes”

  1. Ken says:

    As expected, reference to the smaller event has been removed from the GeoNet website, leaving just one earthquake. The mag. 5.0, 12 km deep, located 120 km west of Greymouth.

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