Magnitude 4.2, Fri Dec 2 2022 1:14 PM


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Origin


PublicID 2022p905434
UTC Time 2022-12-02T00:14:07Z
Latitude -31.54 (± 35.2 km)
Longitude -179.36 (± 94.3 km)
Depth 170 km (± 45 km)
Depth Type free
Earth Model iasp91
Used Phase Count 13
Used Station Count 9
Standard Error 0.72 (s)
Azimuthal Gap 186.70 (degrees)
Minimum Distance 2.59 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (mB) 4.2 (± 0.1)  
mB 4.2 (± 0.1) 3
Mw(mB) 3.2 (± 0.4) 3
ML 3.8 1
MLv 4.5 (± 0.1) 3
M 4.3 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


-8.0-6.0-4.0-2.00.02.04.06.08.0residual (s)0246810Distance (degrees)Pick Residuals

Station Magnitudes (mB)


0.01.02.03.04.05.0Magnitude78Distance (degrees)Station Magnitudes (mB)

Station Magnitudes (ML)


0.01.02.03.04.0MagnitudeDistance (degrees)Station Magnitudes (ML)

Station Magnitudes (MLv)


0.01.02.03.04.05.0Magnitude7Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (mB)


-1.00.01.0Residual78Distance (degrees)Magnitude Residuals (mB)

Magnitude Residuals (ML)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (ML)

Magnitude Residuals (MLv)


-1.00.01.0Residual7Distance (degrees)Magnitude Residuals (MLv)