M 5.8 Seddon Sat, Apr 23 1966

This shock was centered near Cape Campbell, but was felt as far away as Hokitika and Taranaki.

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PublicID 1549063
UTC Time 1966-04-23T06:49:39Z
Latitude -41.64 (± 0.1 km)
Longitude 174.54 (± 0.1 km)
Depth 12 km (± 0 km)
Depth Type operator assigned
Earth Model nz1d
Used Phase Count 11
Used Station Count 6
Standard Error 0.80 (s)
Azimuthal Gap 179.00 (degrees)
Minimum Distance 0.40 (degrees)


Type Magnitude Station Count
Preferred (Mw) 5.8  
ML 5.8 (± 0.1) 8
MS 5.6 0
Mw 5.8 0

GeoNet combines magnitudes into a summary magnitude, M, which consists of a weighted average of the individual magnitudes and attempts to be a best possible compromise between all magnitudes for a range of earthquake sizes. Summary magnitude for GeoNet is then defined as:

M = (2 * MLv + (0.4 * number_of stations(Mw(mB)) - 1) * Mw(mB)) / (2 + (0.4 * number_of_stations(Mw(mB)) - 1))

Where MLv is local magnitude calculated on the vertical component and Mw(mB) is a Mw estimation based of mB by Bormann and Saul (2008).

Origin Map

Map of New Zealand.

Map showing stations with picks used to locate the earthquake. Stations with picks that have a zero weight in the solution are shown as small grey circles. Those with a higher weight are shown as larger circles. The quake is shown by the largest circle.

Pick Residuals

-3.0-2.0- (s)012Distance (degrees)Pick Residuals

Station Magnitudes (ML) (degrees)Station Magnitudes (ML)

Magnitude Residuals (ML)

- (degrees)Magnitude Residuals (ML)