Magnitude 4.3, Sat May 5 1951 9:15 AM


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Origin


PublicID 1544154
UTC Time 1951-05-04T21:15:46Z
Latitude -38.73 (± 0.4 km)
Longitude 175.57 (± 0.4 km)
Depth 166 km (± 43 km)
Depth Type free
Earth Model nz1d
Used Phase Count 6
Used Station Count 5
Standard Error 0.80 (s)
Azimuthal Gap 232.00 (degrees)
Minimum Distance 1.24 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (ML) 4.3 (± 0.3)  
ML 4.3 (± 0.3) 2

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


-4.0-3.0-2.0-1.00.01.02.03.04.0residual (s)012345Distance (degrees)Pick Residuals

Station Magnitudes (ML)


0.01.02.03.04.05.0Magnitude0Distance (degrees)Station Magnitudes (ML)

Magnitude Residuals (ML)


-1.00.01.0Residual0Distance (degrees)Magnitude Residuals (ML)