Magnitude 4.6, Sun May 28 2023 2:53 PM


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Origin


PublicID 2023p397630
UTC Time 2023-05-28T02:53:02Z
Latitude -30.80 (± 28.7 km)
Longitude -178.95 (± 62.5 km)
Depth 100 km (± 0 km)
Depth Type operator assigned
Earth Model iasp91
Used Phase Count 10
Used Station Count 7
Standard Error 0.77 (s)
Azimuthal Gap 187.98 (degrees)
Minimum Distance 1.77 (degrees)

Magnitudes


Type Magnitude Station Count
Preferred (MLv) 4.6 (± 0.4)  
mB 4.7 1
MLv 4.6 (± 0.4) 2
Mw(mB) 3.9 (± 0.4) 0
M 4.6 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


-9.0-7.0-5.0-3.0-1.01.03.05.07.09.0residual (s)0246810Distance (degrees)Pick Residuals

Station Magnitudes (mB)


0.01.02.03.04.05.0MagnitudeDistance (degrees)Station Magnitudes (mB)

Station Magnitudes (MLv)


0.01.02.03.04.05.0Magnitude234567Distance (degrees)Station Magnitudes (MLv)

Magnitude Residuals (mB)


-1.00.01.0ResidualDistance (degrees)Magnitude Residuals (mB)

Magnitude Residuals (MLv)


-1.00.01.0Residual234567Distance (degrees)Magnitude Residuals (MLv)