Magnitude 5.3, Tue Apr 22 1947 11:11 AM


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Origin


PublicID 1543023
UTC Time 1947-04-21T23:11:17Z
Latitude -39.81 (± 0.1 km)
Longitude 176.73 (± 0.1 km)
Depth 20 km (± 0 km)
Depth Type operator assigned
Earth Model nz1dr
Used Phase Count 5
Used Station Count 4
Standard Error 0.22 (s)
Azimuthal Gap 184.00 (degrees)
Minimum Distance 0.18 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (ML) 5.3 (± 0.1)  
ML 5.3 (± 0.1) 3

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


-1.00.01.0residual (s)01234Distance (degrees)Pick Residuals